Holley 550-407 User manual

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4 BBL THROTTLE BODY
FUEL INJECTION SYSTEM
WITH TRANSMISSION CONTROL
550-407 950 CFM 200-600 HP
Polished Aluminum
550-408 950 CFM 200-600 HP
Hard Core Gray™
INSTALLATION MANUAL –199R10772
NOTE: These instructions must be read and fully understood before beginning installation. If this manual is not fully
understood, installation should not be attempted. Failure to follow these instructions, including the pictures may
result in subsequent system failure.
NOTE: Fits all standard square flange and most aftermarket universal flanged spread bore intake manifolds.

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TABLE OF CONTENTS:
1.0 INTRODUCTION......................................................................................................................................................................3
2.0 WARNINGS, NOTES, AND NOTICES.....................................................................................................................................3
3.0 PARTS IDENTIFICATION........................................................................................................................................................4
4.0 ADDITIONAL ITEMS REQUIRED FOR INSTALLATION.........................................................................................................5
5.0 TOOLS REQUIRED FOR INSTALLATION ..............................................................................................................................6
6.0 COOLANT TEMPERATURE SENSOR INSTALLATION..........................................................................................................6
7.0 REMOVAL OF EXISTING COMPONENTS..............................................................................................................................6
8.0 TERMINATOR™ EFI TBI SYSTEM INSTALLATION...............................................................................................................6
8.1 Throttle Body........................................................................................................................................................................6
8.2 Throttle Connections ............................................................................................................................................................7
8.3 MAP Sensor Installation and Vacuum Line Connections.....................................................................................................8
8.4 Fuel Pump, Fuel Line, and Filter Installation........................................................................................................................8
8.5 Oxygen Sensor Installation...................................................................................................................................................8
8.5.1 Oxygen Sensor Mounting Procedure.............................................................................................................................9
8.6 ECU Mounting......................................................................................................................................................................9
9.0 WIRING..................................................................................................................................................................................10
9.1 Important Wiring “Do’s and Don’ts” ....................................................................................................................................10
10.0 WIRING HARNESS INSTALLATION...................................................................................................................................10
10.1 Main Power/Battery Connection.......................................................................................................................................10
11.0 PRIMARY HARNESS INSTALLATION AND SENSOR CONNECTIONS.............................................................................10
11.1 ECU Connectors ..............................................................................................................................................................11
11.2 Harness Routing...............................................................................................................................................................11
11.3 Sensor Connections & Outputs........................................................................................................................................12
11.3.1 Throttle Body Bulkhead Connector (Bulkhead)..........................................................................................................12
11.3.2 Coolant Temperature Sensor (CTS)..........................................................................................................................12
11.3.3 Wide Band Oxygen Sensor (WB02)..........................................................................................................................12
11.3.4 Fuel Pressure (Fuel)..................................................................................................................................................12
11.3.5 CANbus –Handheld (CAN) .......................................................................................................................................13
11.3.6 Ignition (IGN)..............................................................................................................................................................13
12.0 LOOSE WIRES....................................................................................................................................................................13
13.0 IGNITION/ENGINE SPEED INPUT......................................................................................................................................14
13.1 Ignition/Engine Speed Input Wiring..................................................................................................................................15
14.0 ADDITIONAL OUTPUTS......................................................................................................................................................19
14.1 Transmission Wiring.........................................................................................................................................................19
APPENDIX 1.0 PINOUT................................................................................................................................................................21
15.0 PREVIOUS INSTALLATION REQUIRED.............................................................................................................................21
16.0 TERMINATOR™ INSTRUCTIONS AND TUNING ...............................................................................................................21
17.0 INITIAL POWER-UP............................................................................................................................................................22
18.0 HANDHELD NAVIGATION & USE.......................................................................................................................................22
18.1 Making Adjustments..........................................................................................................................................................22
19.0 HOME SCREEN...................................................................................................................................................................23
20.0 CALIBRATION WIZARD......................................................................................................................................................24
21.0 TPS AUTOSET ....................................................................................................................................................................26
22.0 TRANSMISSION SETUP.....................................................................................................................................................27
22.1 Transmission....................................................................................................................................................................27
22.1.1 Trans Setup ...............................................................................................................................................................27
22.1.2 Speed Calc ................................................................................................................................................................28
23.0 SENSOR VERIFICATION....................................................................................................................................................28
24.0 STARTUP.............................................................................................................................................................................29
25.0 SETTING IGNITION TIMING................................................................................................................................................29
26.0 AFTER-STARTUP................................................................................................................................................................29
27.0 IDLE SETTING/THROTTLE PLATE SETTING ....................................................................................................................29
28.0 SELF-TUNING .....................................................................................................................................................................30
29.0 GAUGE SCREENS..............................................................................................................................................................31
29.1 Monitor .............................................................................................................................................................................31
29.1.1 Multi-Gauge ...............................................................................................................................................................31
29.1.2 Monitors .....................................................................................................................................................................32
29.1.3 Diagnostics ................................................................................................................................................................32
30.0 Custom Setups.....................................................................................................................................................................32
30.1 Dash Setup.......................................................................................................................................................................32
30.2 Channels Scaling .............................................................................................................................................................33
31.0 FILE SAVING/LOADING......................................................................................................................................................33
31.1 File.....................................................................................................................................................................................33
31.1.1 ECU Overview............................................................................................................................................................34
31.1.2 ECU Globals ..............................................................................................................................................................34
31.1.3 ECU Data Logging.....................................................................................................................................................35
31.1.4 ECU Hardware/Firmware (HW/FW)...........................................................................................................................35
31.1.5 Local Setup................................................................................................................................................................36

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32.0 BASIC TUNING....................................................................................................................................................................36
32.1 Basic Fuel.........................................................................................................................................................................37
32.1.1 Target AFR ................................................................................................................................................................37
32.1.2 Acceleration Enrichment............................................................................................................................................38
32.1.3 Fuel Prime..................................................................................................................................................................38
32.2 Fuel Learn........................................................................................................................................................................39
32.2.1 Learn Enable/Disable.................................................................................................................................................39
32.2.2 Learn Speed ..............................................................................................................................................................39
32.3 Basic Idle..........................................................................................................................................................................39
32.4 Spark................................................................................................................................................................................40
32.5 Transmission.....................................................................................................................................................................40
32.5.1 Shifts..........................................................................................................................................................................40
32.5.2 WOT Shifts ................................................................................................................................................................41
32.5.3 Torque Converter Clutch (TCC) Parameters .............................................................................................................42
32.5.4 Torque Converter Clutch (TCC) (Un) Lock ................................................................................................................42
32.5.5 Line Pressure.............................................................................................................................................................43
33.0 SYSTEM SETUP..................................................................................................................................................................43
33.1 System Tuning .................................................................................................................................................................43
33.1.1 Outputs ......................................................................................................................................................................44
33.1.2 Engine Setup .............................................................................................................................................................44
33.1.3 Ignition Setup.............................................................................................................................................................45
34.0 ADVANCED TUNING...........................................................................................................................................................46
34.1 Advanced Fuel .................................................................................................................................................................46
34.2 Closed Loop .....................................................................................................................................................................46
34.3 Advanced Learn ...............................................................................................................................................................47
34.3 Advanced Idle...................................................................................................................................................................48
34.3.1 IAC Rampdown..........................................................................................................................................................48
34.3.2 IAC Speed..................................................................................................................................................................49
34.3.3 IAC Startup ................................................................................................................................................................49
34.3.4 Idle Spark...................................................................................................................................................................50
APPENDIX 2.0 SENSOR DIAGNOSTICS AND STATUSES........................................................................................................51
1.0 INTRODUCTION
Holley Performance Products has written this manual for the installation of the TERMINATOR™ EFI TBI fuel injection system. This
manual contains the information necessary for the installation of the hardware contained in this kit, which includes the ECU, wiring, throttle
body, and sensors. It also contains all tuning information. This instruction sheet does not include installation instructions for the fuel
system (pump, filters, regulators and lines). Please read all the WARNINGS and NOTES, as they contain valuable information that can
save you time and money. It is our intent to provide the best possible products for our customer; products that perform properly and
satisfy your expectations. Should you need information or parts assistance, please contact our technical service department at 1-270-
781-9741, Monday through Friday, 8 a.m. to 5 p.m. Central Time. By using this number, you may obtain any information and/or parts
assistance that you may require. Please have the part number of the product you purchased when you call.
2.0 WARNINGS, NOTES, AND NOTICES
NOTE: This system does not contain fuel system components that are required including the fuel pump, fuel filters, fuel
pressure regulator, and lines. These kits can be purchased separately (526-1, 526-2, 526-3, & 526-4).
NOTE: This system is designed for naturally aspirated V8 engines between 250 –600 HP.
WARNING! The TERMINATOR™ EFI systems consist of a number of sophisticated components. Failure of any one component
does not constitute, nor does it justify, warranty of the complete system. Individual service items are available for
replacement of components. If assistance is required or if you need further warranty clarification, you can call
Holley Technical Service at the number shown above.
WARNING! To preserve warranty, these instructions must be read and followed thoroughly and completely before and during
installation. It is important that you become familiar with the parts and the installation of the TERMINATOR™ EFI
system before you begin. Failure to read and understand these instructions could result in damage to
TERMINATOR™ EFI components that are not covered by the warranty and could result in serious personal injury
and property damage.
WARNING! The oxygen sensor in this kit is recommended for use with ONLY unleaded fuel. Use of leaded fuels will degrade
the oxygen sensor and will result in incorrect exhaust gas oxygen readings and improper fuel delivery. Failure to
follow these directions does not constitute the right to a warranty claim.

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WARNING! Failure to follow all of the above will result in an improper installation, which may lead to personal injury, including
death, and/or property damage. Improper installation and/or use of this or any Holley product will void all
warranties.
WARNING! Use of some RTV silicone sealers will destroy the oxygen sensor used with this product. Ensure the RTV silicone
sealant you use is compatible with oxygen sensor vehicles. This information should be found on the RTV package.
WARNING! For the safety and protection of you and others, only a trained mechanic having adequate fuel system experience
must perform the installation, adjustment, and repair. It is particularly important to remember one of the very basic
principles of safety: fuel vapors are heavier than air and tend to collect in low places where an explosive fuel/air
mixture may be ignited by any spark or flame resulting in property damage, personal injury, and/or death. Extreme
caution must be exercised to prevent spillage and thus eliminate the formation of such fuel vapors.
WARNING! This type of work MUST be performed in a well-ventilated area. Do not smoke or have an open flame present near
gasoline vapors or an explosion may result.
3.0 PARTS IDENTIFICATION
ITEM DESCRIPTION QTY SERVICE PART
1 TERMINATOR™ Throttle Body Assembly, Polished (no harness) 1 534-216
TERMINATOR™ Throttle Body Assembly, Hard Core Gray™(no harness) 1 534-217
2 TERMINATOR™ EFI ECU & Hand-Held Controller 1 554-114 (ECU) 553-108 (Controller)
3 Main Power Harness 1 558-308
4 TERMINATOR™ EFI Main Wiring Harness 1 558-414
5 Wide Band Oxygen Sensor 1 554-101
6 Coolant Temperature Sensor 1 534-2
7 Input/Output Harness 1 N/A
8 Air Cleaner Gasket 1 108-4
9 Flange Gasket 1 108-10
10 Manifold Flange Studs 4 N/A
11 Oxygen Sensor Weld Ring 1 534-49
12 Throttle Bracket, Throttle Only 1 20-151
13 Throttle and Cruise Control Stud 1 N/A
14 Throttle Lever Ball 1 N/A
15 Throttle Lever Stud 1 N/A
16 Transmission Kickdown Stud 1 N/A
17 Grommet 1 N/A
18 Washers 4 N/A
19 Lock washers 3 N/A
20 1/4-28 Nuts 2 N/A
21 5/16-24 Nuts 4 N/A
22 Ignition Adapter 1 N/A
23 ¼-20 x 5/8 Socket Head Cap Screw 1 N/A
24 Transmission Harness 1 558-405
TBI Service Parts:
TERMINATOR™ Throttle Body Sub-Harness 1 558-418
Air Charge Temperature Sensor 1 554-121
Terminator 80PPH Fuel Injector (requires purchase of 4) 1 522--801
MAP Sensor 1 554-120
Idle Air Control (IAC) Motor 1 543-105
Throttle Position Sensor (TPS) 1 9920-110
40 AMP Relay 1 534-26
Optional Parts:
Small Cap GM HEI Ignition Adapter 1 558-304
Ford TFI Ignition Adapter 1 558-305
Ford Transmission Kickdown Bracket Kit 1 20-152

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Item 1 Item 2 Item 3
Item 4 Item 5 Item 6 Item 7
Item 8 Item 9 Item 10 Item 11 Item 12
Item 13 Item 14 Item 15 Item 16 Item 17 Item 18 Item 19
Item 20 Item 21 Item 22 Item 23 Item 24
4.0 ADDITIONAL ITEMS REQUIRED FOR INSTALLATION
Fuel System Return Fuel Lines
A 0-100 psi fuel gauge or pressure transducer is recommended to check for proper fuel pressure. PN 554-102 is a 0-100 PSI pressure
sensor that can be purchased as well that will plug into the TERMINATOR™ harness to check and monitor fuel pressure. It requires a
1/8” NPT port for installation (Holley fuel pressure regulators have an 1/8” NPT port)
In addition to the above list, the engine must be equipped with a four barrel intake manifold and the vehicle must be in good operating
condition. Any square flange Holley type intake manifold will work. A spread bore intake manifold may work with no adapter as long as it
is an aftermarket “universal flange” (meaning it has dual bolt patterns), and as long as it has enough material such that no vacuum leaks
occur along the perimeter of the throttle body. If there is not enough material, a sealing plate (Weiand® PN 9006) can be used. Factory
dual plane intakes will require an adapter (PN 17-6).

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5.0 TOOLS REQUIRED FOR INSTALLATION
Standard wrench set Small blade screwdriver Allen Wrench set
Medium blade screwdriver #2 Phillips screwdriver Digital Volt meter
Drill and assorted bit sizes Hole saw (2”) (depending on ECU location) Terminal crimping tool
Factory Service Manual for your vehicle 02 Bung Installation (drilling, welding)
An assistant is necessary for some installation and adjustment procedures and should be present for safety reasons.
6.0 COOLANT TEMPERATURE SENSOR INSTALLATION
The coolant temperature sensor (Item 6) must be installed in a coolant passage in either the intake manifold or cylinder head. The sensor
has 3/8” NPT threads. If only a ½” NPT port is available, an adapter will have to be used. It is best to drain the some of the coolant before
the sensor is installed. Do not install the sensor in the thermostat housing, or in an area that will not see a constant flow of coolant.
7.0 REMOVAL OF EXISTING COMPONENTS
1. Disconnect the battery and remove the air cleaner.
2. Before disconnecting any vacuum hoses, it is a good idea to sketch out the vacuum hose routing. Using masking tape and a
permanent marker, mark all the vacuum hoses, vacuum sources, and ports before removing the old fuel delivery system.
3. Remove and discard the fuel line that connects to the carburetor from the mechanical fuel pump. This will not be needed in the
installation. Remove the throttle return springs and keep for later installation.
4. If required, replace the intake manifold at this time. Proceed to step six if this is not required. A 4-BARREL STOCK OR
AFTERMARKET SQUARE FLANGE INTAKE MANIFOLD, AS WELL AS SOME UNIVERSAL FLANGE AFTERMARKET SPREAD
BORE INTAKE MANIFOLDS ARE REQUIRED FOR THE INSTALLATION OF THE HOLLEY TERMINATOR™EFI TBI system. An
option with some GM and Chrysler engines is to use manifold adapter Holley PN 17-6. This adapts the spread bore
carburetor manifold to the Holley square flange.
5. Place clean shop towels or rags into the manifold opening to prevent dirt or debris from entering the engine. Keep exposed ends of
the vacuum and fuel lines free from dirt or debris.
WARNING! Failure to cover the intake opening with a clean towel could result in dirt or debris entering the engine. Dirt or debris
in the induction system can cause engine damage, which may necessitate a complete engine overhaul.
6. Remove all traces of the old gasket material from the intake manifold mounting flange. DO NOT gouge the intake manifold sealing
surface during removal of old gasket material. Failure to remove all traces of the old gasket material will result in vacuum leaks that
will be difficult to detect later. Sealing flanges must be clean and dry before installation.
7. Remove the shop towels from the intake and vacuum out the intake channel to ensure no dirt or debris is left in the intake system.
Place a shop towel over the entire intake opening until you are ready to install the new TERMINATOR™ EFI TBI.
8.0 TERMINATOR™ EFI TBI SYSTEM INSTALLATION
8.1 Throttle Body
NOTE: A 4 barrel intake is required for the installation of the Holley TERMINATOR™ EFI TBI system.
1. Install the four manifold flange studs (Item 10) into the intake manifold. Install the throttle body gasket (Item 9) between the manifold
and the 4 barrel throttle body injection unit. Check for sufficient thread engagement of the throttle body hold down studs and nuts.
DANGER! Check for proper clearance between engine components, such as the distributor, coil, etc., and the throttle body. If
any interference is found, correct the condition before continuing. Failure to do so can result in damage to the
engine components or the throttle body.
DANGER! Check for proper clearance between the air cleaner and the engine compartment cover hood. If any interference is
found, correct the condition before continuing. Failure to do so can result in damage to the compartment cover,
hood, or engine components.
2. Place the throttle body in position over the manifold flange studs with the throttle lever located on the driver’s side.

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3. Tighten the throttle body down in a criss-cross pattern being careful not to over-tighten. Proper torque is 5-7 ft./lbs.
WARNING! Over tightening the TBI manifold flange hold-down-nuts may result in a warped or cracked throttle body. The TBI
hold down nuts should be tightened down progressively in a criss-cross pattern to 5-7 ft./lbs., to prevent leaks and
avoid causing damage to the throttle body. A TBI that has been damaged due to negligence of the owner will void
the warranty.
8.2 Throttle Connections
1. The throttle lever on the TERMINATOR™ is designed to directly connect to most throttle cables. Several throttle studs are included.
It is also designed to directly connect up to GM transmissions including TH350, TH200R, and TH700R4. A stud is included for most of
these transmissions.
2. Install the proper throttle and transmission studs and secure with two of the included lock washers (Item 19) and ¼-28 nuts (Item 20).
Figure 1
3. There is throttle cable bracket included with the kit. Once installed, use ¼-20 x 5/8 SHCS (Item 23) and a lock washer (Item 19) to
secure.
Bracket Installed (Throttle Only –item 12)
4. Once the throttle linkage is attached, have an assistant get in the vehicle and fully actuate the throttle controls. Make the necessary
adjustments to the throttle linkage to ensure that the throttle plates are vertical when the throttle control is wide open. Work the
throttle linkage back and forth several times to ensure it operates smoothly with no binding or sticking.
DANGER! A sticking throttle may result in uncontrolled engine or vehicle speed. This could cause property damage, personal
injury, or death. A sticking throttle may be caused by improperly installed throttle cables, lack of clearance for any of
the throttle linkage, or by a binding throttle linkage. Check all throttle cables for proper installation and alignment and
actuate the throttle to check for any potential binding or clearance problems. Repair any problems before continuing.
5. If the vehicle is equipped with an automatic transmission, ensure that the transmission kickdown is properly adjusted. Follow the
vehicle manufacturer’s procedure for the correct adjustment procedure.
NOTE: On late model GM and Ford overdrive transmissions with a lockup torque converter, make sure the lockup function is properly
retained. Failure to do so will result in premature transmission failure.

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NOTE: On Chrysler vehicles, a lever extension will be needed, Holley PN 20-7. Van applications may require the use of throttle lever
extension Holley PN 20-14.
6. Install external throttle return springs that you previously removed from the carburetor. External springs should be used in addition to
the springs on the throttle body itself. Have an assistant get in the vehicle and fully depress the accelerator pedal. Make the
necessary adjustments to the throttle linkage to insure that the throttle reaches wide-open position when the accelerator is depressed.
Work throttle linkage back and forth several times to ensure that it operates smoothly with no binding or sticking.
DANGER! Failure to attach the throttle return spring or a sticking throttle may result in uncontrolled engine or vehicle speed,
which could cause personal property damage, serious injury, or death.
8.3 MAP Sensor Installation and Vacuum Line Connections
1. Connect the vacuum lines that were disconnected in section 7.0. Figures 2 & 3 show the function of the ports in the TERMINATOR™
throttle body.
Figure 2 Figure 3
8.4 Fuel Pump, Fuel Line, and Filter Installation
A complete high pressure EFI fuel system must be installed for the TERMINATOR™. The pump should be capable of supplying 255
liters/hour or 400 lb./hr. of fuel at 45 PSI. If using an in-line fuel pump, there should be a coarse pre-filter before the pump. All systems
should contain a 10 micron post filter after the fuel pump. An EFI fuel pressure regulator is required. It should be installed after the
throttle body. See Figure 4 below for proper fuel system plumbing.
NOTE: The regulator pressure should be set to 43-45 PSI when adjusting the fuel pressure regulator with the fuel pump running.
Holley offers four fuel system kits. These kits contain all components except the return line. They include detailed instructions
(downloadable at www.holley.com). These kits are:
526-1 –Braided Stainless Lines, Billet Pump, Regulator, and Filters
526-2 –Pro-Lite 350 Hose, Billet Pump, Regulator, and Filters
526-3 –Super Stock Hose, Billet Regulator, 12-920 Fuel Pump, and Filter
526-4 –Super Stock Hose, Billet Regulator, 12-920 Pump, and Metal Filters
Figure 4
8.5 Oxygen Sensor Installation
The oxygen sensor should be mounted at a point where it can read a good average of all the cylinders on one bank. This would be
slightly after all the cylinders merge. Do NOT mount the sensor far back in the exhaust as this will negatively impact closed loop
operation response. If you have long tube headers, mount the sensor approximately 1-10” after the collector.You must have no less than
18 –24” of exhaust pipe after the sensor.

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TERMINATOR™ EFI systems come with a Bosch wideband oxygen sensor (Item 5). Make sure your sensor looks like Figure 5.
Figure 5
8.5.1 Oxygen Sensor Mounting Procedure
NOTE: Never run the engine with the oxygen sensor installed if it is not plugged in and powered by the ECU, or it will be damaged. If
you need to plug the hole temporarily, use an O2 sensor plug or a spark plug with an 18mm thread.
NOTE: Someone with experience in welding exhaust systems should install the oxygen sensor boss. Any competent exhaust shop will
be able to perform this task at a minimum cost. (Note: If you weld on the car, make sure all wiring to the ECU is disconnected,
and its best to remove the ECU from the vehicle when welding).
WARNING! Use of leaded fuel will degrade an oxygen sensor. Prolonged use is not recommended unless periodic replacement
is performed.
WARNING! Use of some RTV silicone sealers will destroy the oxygen sensor used with this product. Ensure the RTV silicone
sealant you use is compatible with oxygen sensor vehicles. This information should be found on the RTV package.
1. Locate a position for the oxygen sensor as close to the engine as possible. If your vehicle has catalytic converters, the oxygen sensor
MUST be located between the engine and the catalytic converters.
Figure 6
NOTE: The oxygen sensor should be mounted in such a way that the condensation in the exhaust tubing will not enter the sensor.
Mount the O2sensor in the upper half of the exhaust tubing, with the angle “x”, shown above, being greater than 10°. Figure 6
indicates that the sensor can be mounted on either side of the exhaust tubing.
2. Drill a 7/8” hole in the location picked for the sensor. Weld the threaded boss into the 7/8” hole. Weld all the way around the boss to
insure a leak proof connection. Install the oxygen sensor into the threaded boss and tighten securely. It is a good idea to add anti-
seize to the threads to aid in removal. Do not get any anti-seize on the tip of the sensor.
3. On vehicles equipped with an AIR pump, the oxygen sensor must be mounted before the AIR injection into the exhaust, or the AIR
pump must be disconnected. Holley recommends that if the AIR is injected into both exhaust manifolds, mount the oxygen sensor
into the pipe immediately after the exhaust manifold. Disconnect the AIR pump tube from the exhaust manifold and plug both ends.
Check with local ordinances for the legality of this procedure in your area.
WARNING! Failure to disconnect the AIR pump or locating the oxygen sensor downstream from AIR injection will result in an
extremely rich mixture, which could cause drivability problems and severe engine damage.
8.6 ECU Mounting
The ECU can be mounted inside the passenger compartment (preferable location) or in the engine compartment. If mounted in the
engine compartment, follow these guidelines:
The ECU should be located such that it isn’t being directly hit by water or road debris.
It should also be located such that it isn’t extremely close to exhaust manifolds or headers.
It should be mounted such that it is as far away from spark plug wires, CD ignition boxes, or other “electrically noisy” devices as
is reasonable possible.
Make sure the connector end of the ECU is pointed DOWN such that water can’t make its way into the ECU terminals.

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The ECU comes with mounting hardware (stainless steel screws and nuts). The ECU has plastic shoulders on the mounting ears. DO
NOT REMOVE THEM. Do not over-tighten the mounting hardware if the ECU is not mounted on a flat surface.
9.0 WIRING
This section overviews how to properly install the wiring harnesses for this system.
9.1 Important Wiring “Do’s and Don’ts”
An EFI system depends heavily on being supplied a clean and constant voltage source. The grounds of an electrical system are just as
important as the power side.
TERMINATOR™ ECU’s contain multiple processing devices that require clean power and ground sources. The wiring harnesses for them
must be installed in such a manner that they are separated from “dirty” power and ground sources.
DO’S
Install the main power and ground directly to the battery. To the POSTS/TERMINALS, not to any other place.
Keep sensor wiring away from high voltage or “noisy/dirty” components and wiring, especially secondary ignition wiring (plug
wires), ignition boxes and associated wiring. It is best that the plug wires not physically contact any EFI wires.
Properly crimp or crimp and solder any wire connections. Apply quality heat shrink over any of these connections.
It is critical that the engine has a proper ground connection to the battery and chassis.
DON’TS
NEVER run high voltage or “noisy/dirty” wires in parallel (bundle/loom together) with any EFI sensor wiring. If wires need to
cross, try to do so at an angle.
Do not use the electric fan outputs to directly power a fan. They must only trigger a relay.
Do not use improper crimping tools.
Don’t use things like “t-taps”, etc. Use proper crimpers/solder and heat shrink.
It is never recommended to splice/share signal wires (such as TPS, etc.) between different electronic control units (i.e.
“piggyback”).
Do not connect the red/white switched +12V wire to “dirty” sources, such as the ignition coil, audio systems, or 12V sources
connected to HID head lamps.
10.0 WIRING HARNESS INSTALLATION
The TERMINATOR™ throttle body comes with sensors pre-wired for easy installation.
10.1 Main Power/Battery Connection
The TERMINATOR™ ECU has a main battery power and ground connector on the right side of the ECU. The bottom position, Terminal
“A” is the ground (black wire). The black wire should go to the negative post DIRECTLY on the battery. The upper position, Terminal “B”
is the positive terminal (red wire). The red wire should go to the positive post DIRECTLY on the battery. If you have a “dual post” battery,
it is a great idea to purchase separate posts/studs to connect the ECU power and ground to the non-used terminals. Always use the
fused power cable (Item 3) with the proper connectors supplied by Holley only. Don’t connect to the ECU until after ALL wiring and
installation is performed.
Figure 7
11.0 PRIMARY HARNESS INSTALLATION AND SENSOR CONNECTIONS
These sections review the Main Harness installation and sensor connections that must be completed. The Main Harness (Item 4) is the
primary harness that supports all the primary engine sensors, fuel and ignition. There are two main connectors for this harness that plug
into the ECU.

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Figure 8
11.1 ECU Connectors
TERMINATOR™ ECU –The TERMINATOR™ ECU has six connectors (three are unused). The main harness plugs into the J1A & J1B.
J1A - The first connector next to the USB connector is the “J1A” connector (34 pin). This connector is primarily an “Input”
connector. It contains all the sensor inputs and wide band oxygen sensor control.
J1B - The second connector is the “J1B” connector (26 pin). This connector is the “output” connector. It has 8 injector outputs
and outputs for other devices.
J4 –Transmission Harness Connection - Connect the transmission harness into J4.
Figure 9
*USB is not used on TERMINATOR™ EFI
11.2 Harness Routing
If the ECU is mounted in the interior, it will have to be routed through the firewall into the engine compartment. Use a 2” hole saw to
create a hole in a desired location if no other point of access is available. A grommet is supplied for a 2” hole to seal this area.

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If the ECU is mounted in the engine compartment, the hand-held tuning module cable will have to be routed to the “CAN” connector on the
main harness (located near the ECU connector main connector). This is assuming you want to access the hand-held module after
startup. This will require routing the small CAN connector somewhere through the firewall.
Connect the J1A and J1B connectors of the main harness into the ECU.
About 18” from the ECU main connectors is a 40A Relay. This powers the injectors and fuel pump. There is also a 20 amp fuse for the
injectors and fuel pump pre-installed in this location.
The transmission harness should be routed as desired.
11.3 Sensor Connections & Outputs
The following indicates the primary sensors that are required to be connected. Each connector on the main harness is labeled with the
sensor name. The name on this label for each sensor is in parenthesis below.
11.3.1 Throttle Body Bulkhead Connector (Bulkhead)
Connect the 14 bin bulkhead connector in the main harness to the connector of the throttle body.
11.3.2 Coolant Temperature Sensor (CTS)
Connect to the Coolant Temperature sensor which should have been installed in an engine coolant passage.
Figure 10 CTS
11.3.3 Wide Band Oxygen Sensor (WB02)
Connect to the oxygen sensor connector to the oxygen sensor previously installed. If you need an extension cable, one is available from
Holley (P/N 534-199). The TERMINATOR™ systems are intended to be used with a Bosch wide band oxygen sensor supplied by Holley.
Figure 11 WBO2
11.3.4 Fuel Pressure (Fuel)
A fuel pressure transducer connector is pre-installed in the main harness. The system is plug-and-play configured for a Holley 100 PSI
pressure transducer (can be purchased under PN 554-102). If these are not connected to a pressure transducer, the Fuel Pressure will
read “LEr” on the hand-held display. This will not cause any issues. Connect to the transducer (if installed).
Figure 12 Fuel

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11.3.5 CANbus –Handheld (CAN)
The handheld controller is used for create of an initial calibration for the system, allows for simple tuning changes to be performed, and is
also used to view various information of the EFI system. It should be installed such the handheld controller can be easily used in the
passenger compartment. The handheld has a single four pin connector that connects to the main harness. Plug the connector into the
main wiring harness into the plug marked “CAN”. This plug is located 21 inches from the ECU connector. The handheld does not have to
remain in the vehicle or utilized after the vehicle is set up and running properly.
There is a second connector marked “CAN 2”. This is for additional CAN devices. See Figure 13.
Figure 13 Harness to Handheld
11.3.6 Ignition (IGN)
There is a 10 pin connector marked “IGN”. This is to connect to various ignition systems. This is not required for some applications.
Figure 14
12.0 LOOSE WIRES
Figure 15
The following loose wires in the main wiring harness should be connected as follows on all systems. All of these wires come out of the
harness about 40” from the ECU connectors except for the “12V Switched” wire.

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12V Switched –Color = Red/White –Should be connected to a clean +12 volt power source. Power source should only be active when
the ignition is on. Make sure source has power when engine is cranking as well (check with voltmeter). Not all sources apply power when
the ignition switch is in “cranking” position. This wire is located approximately 7” from the ECU connectors. DO NOT connect to a
“DIRTY” source like an ignition coil! Refer to Figure 15.
12V Battery –Color = Red –Should be connected directly to the battery. This powers the fuel pump and fuel injectors. This wire is
protected by a fuse in a sealed fuse holder. The fuse holder is located about 18” from the ECU connector. A fuse is pre-installed (20A).
12V Fuel Pump –Color = Green - Used to directly power a fuel pump (+12 volt). Do not use this wire to power fuel pumps that require
over 15 Amps. For high current pumps, use this wire to trigger a separate relay and use larger gauge wire to feed the pump - 10 gauge is
recommended. The pump that include with TERMINATOR™ systems draws less than 10 Amps and can be powered directly by this wire.
The fuel pump also requires a ground wire. Run a wire from the negative side of the fuel pump. Connect it to a solid chassis/frame
ground.
Chassis Ground –Color = Black –Connect to a chassis ground point that has excellent connectivity with both the engine and battery.
This ground should not be connected at the same location as other grounds.
“Coil – ”–Color = Yellow –See section 13.0 below. This is an RPM input wire used for some applications.
13.0 IGNITION/ENGINE SPEED INPUT
The most important signal for the ECU is the Engine Speed input. It is critical that this is configured and wired correctly or poor
performance will result.
There are 3 engine speed options on the TERMINATOR™ systems. Each one is wired differently. If these are wired incorrectly, it is
easily possible to permanently damage the ECU so pay close attention to proper wiring. These options are described below and wiring
diagrams are supplied below the descriptions:
OPTION 1) “Coil -”engine speed input –Use this if:
You are using a stock type mechanical advance distributor with a stock inductive ignition coil. Examples of this would be any
older style points distributor, a 1974-1981 GM large cap HEI.
Do NOT use this input if you are using an aftermarket Capacitive Discharge (CD) ignition system such as a MSD, Mallory, or
others. The ECU will be damaged if you connect to a capacitive discharge type ignition coil.
NOTE: Using this input, the EFI will NOT control the ignition timing of the engine. The timing will be based on the distributor initial,
mechanical, and vacuum advance, just like it did with a carburetor.
OPTION 2) “Tach Out” engine speed input -
If you are using an aftermarket Capacitive Discharge (CD) ignition system such as a MSD, Mallory, or others, you need to
connect to the “Tach Out” connection or wire these systems provide. This is a 12 volt square wave output.
CAUTION! NEVER, NEVER connect any of the EFI wires to the coil on any CD type ignition system. The ECU will be permanently
damaged!
NOTE: Using this input, the EFI will NOT control the ignition timing of the engine. The timing will be based on the distributor initial,
mechanical, and vacuum advance, just like it did with a carburetor.
OPTION 3) “GM Small Cap HEI” Computer Controlled Distributor (Requires Holley Ignition Adapter PN 558-304) –
Small and Big Block Chevy engines can use a small cap GM HEI computer controlled distributor that was available on factory GM
vehicles from the 1980’s through mid-1990’s. This distributor provides an engine speed signal to the EFI, as well as allowing the
EFI to control the ignition timing.
Figure 16 Distributor and Close Up of Distributor
OPTION 4) “Ford TFI” Computer Controlled Distributor (Requires Holley Ignition Adapter PN 558-305) –
Ford Sequentially Injected 5.0-5.8L engines from 1987-1995 used this distributor.

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13.1 Ignition/Engine Speed Input Wiring
OPTION 1 –“Coil -”–Option one uses the “Yellow Wire” for engine speed input. The yellow wire is a loose wire located 52” from the
ECU connectors. It is bundled with several other loose wires. The following two diagrams show how to wire to the two most common
applications which are:
1) Any General Motors engine equipped with a factory large cap HEI distributor equipped with mechanical/vacuum advance (Figure
17).
2) Any engine equipped with a factory mechanical advance distributor and separate canister style coil. This would include any
points style distributor (Fig. 18).
Figure 17 below shows how to connect to a large cap HEI distributor.
Figure 17
Figure 18 below shows how to connect to a factory style ignition with a canister style coil.
Figure 18

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OPTION 2 –“Tach Out” –If using an aftermarket Capacitive Discharge (CD) ignition system, you need to connect to the “Tachometer
Output” connection on the ignition box. To do so, you need to install the included ignition adapter that comes with your kit. This adapter
will have a single “yellow/black” wire (yellow wire with a black stripe) that you will connect to the tach out on the ignition box. This output
usually is typically a spade type connector on the side of the box, or a wire coming out of the box. This adapter looks like this:
Figure 19
Connect it to the main EFI harness to the connector marked “IGN” (Ignition). Connect the yellow/black wire to the “tach out” connection on
your ignition box. If you don’t know what wire this is, contact the tech service department for the ignition system you purchased.
Figure 20
OPTION 3 - “GM Small Cap HEI” Computer Controlled Distributor – An ignition adapter to connect to a computer controlled small cap
HEI distributor. This adapter looks like:
Figure 21
Connect this adapter to the main EFI harness to the connector marked “IGN” (Ignition). Connect the other end to the 4 pin connector on
the HEI distributor. You will need to supply the wiring to connect the distributor to the coil.

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Figure 22 shows how to wire when NOT using an aftermarket CD box. Figure 23 Shows how to wire when using an aftermarket CD box.
Figure 22
Figure 23

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OPTION 4 –“Ford TFI”- Small Block Ford engines can use a TFI distributor from sequentially fuel injected 5.0/5.8L Ford engines. This
requires adapter P/N 558-305. Use one of the two following diagrams to wire the ignition.
Figure 24
Figure 25

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14.0 ADDITIONAL OUTPUTS
There are 3 optional outputs available on the system that can be used for the following features:
Air Conditioning Shutdown at wide open throttle
Electric Fan #1 output
Electric Fan #2 output
There outputs are located in the “Input/Output” connector. This is a 3 Pin connector is located about 52 inches from the ECU. A mating
harness is included with the system.
The following indicates proper wiring for these features.
A/C Shutdown –This output will provide a +12 volt output a defined throttle position. This output can be used to trigger a relay that
deactivates the A/C at higher throttle positions. This may require the installation of a 5 pole relay in the existing A/C wiring. This wire is
located in pin A of the 3 pin Input/Output connector and is Gray with a Yellow stripe.
Electric Fan #1 output –This output will provide a ground output to trigger a relay used for a cooling fan. This output should never be
directly connected to a fan, but the relay that powers the fan. It should be connected to the ground trigger of the relay. This wire is
located in pin B of the 3 pin Input/Output connector and is Gray with a Black stripe.
Electric Fan #2 output –This output will provide a ground output to trigger a relay used for a cooling fan. This output should never be
directly connected to a fan, but the relay that powers the fan. It should be connected to the ground trigger of the relay. This wire is
located in pin C of the 3 pin Input/Output connector and is Gray with a Green stripe.
Figure 26
14.1 Transmission Wiring
The transmission harness can be used on 4L60E, 4L65E, 4L70E, 4L80E, and 4L85E transmissions. Each connector should be labeled.
Transmission ECU Connector (P4) –Plugs into the ECU. Plugs into the last connector opposite the main harness.
Main Transmission Connector –Simply plugs into the connector on the transmission. Located on the driver’s side of a 4L80E (installed
horizontally) and the passenger side on a 4L60E (installed vertically).
Vehicle Speed Sensor (VSS)/Transmission Output Speed Sensor (OSS) –Located on the rear drivers side on a 4L80E and the rear
passengers side on a 4L60E
Turbine Speed Sensor –The 4L60E does not have a turbine speed sensor. It is located towards the front driver’s side on a 4L80E. Note
that a 4L70E has one internally wired, but is not connected to the Holley harness. The turbine speed sensor is not used for any
calculations in the ECU, just for monitoring purposes.
Brake Switch (Grey) –Wired to the brake light switch. This must be installed to a +12v source (as most brake light switches are). This
input is used to unlock the torque converter when the brakes are applied.
Ground (Black) –Connect to a good chassis/engine ground source
Power (Red) –Supplies power to the transmission solenoids. This should be connected to a +12v switched power source (must be
capable of supplying 5 amps).
NOTE: The power supplying this wire must NOT be tied to the same point that the ECU switched power wire (red/white wire) is
connected to. If they are tied together, the transmission power could back-feed power to the ECU and the ECU/engine will not
shut off when the key is turned off. Use a relay or separate switched ignition power pickup point to supply power to the
transmission harness.

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Main Transmission Connector
Vehicle Speed Sensor Turbine Speed Sensor
Transmission ECU Connector Loose Wire Bundle