Holley Sniper EFI Stealth 4500 User manual

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
Sniper Stealth 4500 (550-841 Shiny, 550-842 Black, & 550-843 Gold)
Holley Sniper EFI FUEL INJECTION INSTALLATION MANUAL

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Read this manual before using this product.
WARNING!
This instruction manual must be read and fully understood before beginning installation. If the instructions
are not fully understood, installation should not be attempted. Failure to follow the instructions may result in
subsequent system failure and could result in serious personal injury and/or property damage. Keep this
manual.
For the safety and protection of you and others as well as your vehicle, only a trained mechanic having
adequate fuel system experience should perform the installation, adjustment, and repair.
While undertaking any work involving the fuel system, 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. All work involving this product and the fuel system generally 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.
Any components damaged due to failure to follow these instructions will not be covered by the warranty.
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, please call Holley Technical Service at 1 [phone].

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TABLE OF CONTENTS
INTRODUCTION & SYSTEM REQUIREMENTS...........................................................................................................5
Engine Requirements................................................................................................................................................5
Fuel System Requirements .......................................................................................................................................5
TOOLS REQUIRED FOR INSTALLATION....................................................................................................................5
PARTS IDENTIFICATION..............................................................................................................................................6
PREPARING THE THROTTLE BODY FOR INSTALLATION........................................................................................7
THROTTLE BODY INSTALLATION...............................................................................................................................7
OXYGEN SENSOR INSTALLATION.............................................................................................................................8
COOLANT TEMPATURE SENSOR INSTALLATION....................................................................................................9
FUEL SYSTEM CONNECTIONS.................................................................................................................................10
ECU WIRING OVERVIEW...........................................................................................................................................11
BASIC WIRING INSTALLATION..................................................................................................................................12
GENERAL WIRING REFERENCE...............................................................................................................................13
Throttle Body Connections ......................................................................................................................................13
Pigtail & Loose Wire Connections............................................................................................................................13
Connecting Sniper EFI Touchscreen LCD to Sniper EFI.........................................................................................14
NON TIMING CONTROLLED IGNITION SYSTEM WIRING .......................................................................................17
Coil (-) [no timing control].........................................................................................................................................17
Ignition Box Tach Output (No Timing Control).........................................................................................................18
TIMING CONTROLLED IGNITION SYSYEM WIRING................................................................................................20
Timing Control Preface:...........................................................................................................................................20
MSD (Magnetic) Distributor [Timing Control] ...........................................................................................................20
Holley Dual Sync Distributor [Timing Control]..........................................................................................................25
Sniper EFI HyperSpark Distributor [Timing Control] ................................................................................................31
HANDHELD NAVIGATION ..........................................................................................................................................32
Possible Screens.....................................................................................................................................................32
INITIAL EFI SETUP .....................................................................................................................................................34
Calibration Wizards..................................................................................................................................................34
Sensor Verification...................................................................................................................................................38
Prestart Checklist.....................................................................................................................................................39
First Startup.............................................................................................................................................................39
After Startup.............................................................................................................................................................39
Ignition Timing Check (without Timing Control) .......................................................................................................40
Ignition Timing Check (ECU Controlling Timing)......................................................................................................41
THROTTLE BLADE ADJUSTMENT ............................................................................................................................42
SYSTEM SETUP .........................................................................................................................................................43
Ignition System Setup..............................................................................................................................................43
BASIC TUNING............................................................................................................................................................44
Basic Fuel................................................................................................................................................................44
Target AFR..............................................................................................................................................................45
Acceleration Enrichment..........................................................................................................................................45
Fuel Prime ...............................................................................................................................................................46
Closed Loop Enable/Disable ...................................................................................................................................46
Learn Enable/Disable ..............................................................................................................................................47

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Basic Idle.................................................................................................................................................................47
Spark.......................................................................................................................................................................48
SYSTEM TUNING........................................................................................................................................................48
Outputs....................................................................................................................................................................49
Engine Setup...........................................................................................................................................................50
Sniper Setup............................................................................................................................................................50
Ignition Setup...........................................................................................................................................................51
Static Timing............................................................................................................................................................51
ADVANCED TUNING ..................................................................................................................................................52
IAC Rampdown........................................................................................................................................................54
Idle Spark ................................................................................................................................................................55
Idle Speed ...............................................................................................................................................................56
Advanced 2..............................................................................................................................................................56
SNIPER EFI MONITOR...............................................................................................................................................57
Monitors...................................................................................................................................................................57
Multi-Gauge.............................................................................................................................................................58
Changing Monitor Channel Scaling .........................................................................................................................58
Custom Configuring Dash 1 Dash 2 or Dash 3........................................................................................................60
NITROUS TUNING ON HANDHELD ...........................................................................................................................60
BOOST CONTROL ON HANDHELD...........................................................................................................................60
ADVANCED TABLES ON HANDHELD .......................................................................................................................61
TUNING DEFINITIONS................................................................................................................................................61
DATALOGGING & FILE TRANSFERS ........................................................................................................................70
Taking a Datalog with the 3.5” TSCLCD..................................................................................................................70
Triggering an Automatic Datalog .............................................................................................................................70
Changing Diagnostics Type of Datalog....................................................................................................................70
Downloading Global Configuration from Sniper EFI Throttle Body to SD card: .......................................................71
Loading Calibration into Sniper EFI ECU.................................................................................................................71
LAPTOP SUPPORT.....................................................................................................................................................72
Viewing Global Configuration with Sniper EFI Software without USB Cable: ..........................................................72
Viewing Datalog with Sniper EFI Software: .............................................................................................................73
TROUBLESHOOTING.................................................................................................................................................74
Troubleshooting Guide ............................................................................................................................................74
Sensor Verification...................................................................................................................................................74
Sensor Diagnostics and Statuses............................................................................................................................74

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INTRODUCTION & SYSTEM REQUIREMENTS
Holley Performance Products has written this manual for the installation of the Sniper EFI TBI fuel injection system.
This basic manual contains the information necessary for the installation of the throttle body, wiring, and sensors.
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.
Engine Requirements
Before moving forward with the installation, please verify your vehicle meets the engine and fuel system requirements
below:
Engine is in sound mechanical condition
Engine horsepower is between 800-1500
Engine is an 8 cylinder
Engine has a 4 barrel, 4500 style flange intake manifold*
Unleaded fuel only
Any RTV silicone sealants used on the engine are sensor safe
* Any 4500 flange intake manifold will work. Make sure to use proper gaskets to seal the throttle body to the intake
manifold and ensure that there are no vacuum leaks.
Fuel System Requirements
The Sniper EFI system requires a high pressure fuel pump capable of operating at 60 psi with at least 50 gallon per
hour of fuel flow (more fuel flow may be needed for higher horsepower engines). When selecting a pump, and lines, be
sure each component is designed to perform at high pressure. Holley offers a variety of fuel pumps, hoses and
accessories to complete your installation. For best results, Holley strongly recommends an in-tank pump. Installing the
fuel pump in the tank results in quieter operation, less chance of cavitation and a reduction in pump temperature. If
mounting the pump in the tank is not an option, install the pump as close as possible to the tank. Within 2-feet of
sending unit is recommended. Once the fuel system is installed checking the fuel pressure on the inlet side of the
Sniper EFI is recommended, fuel pressure needs to be between 55-65 PSI.
TOOLS REQUIRED FOR INSTALLATION
Standard Wrench Set Small Blade Screwdriver Allen Wrench Set
Medium Blade Screwdriver #2 Phillips Screwdriver Digital Voltmeter
Drill and Assorted Bit Sizes Terminal Crimping Tool
Factory Service Manual for your vehicle 7/8” Drill Bit (step-bit recommended)
An assistant is necessary for some installation and adjustment procedures and should be present for safety reasons.
WARNING! Before disconnecting the battery, we recommend locating a Clean Switched 12 volt ignition source.
This source needs to have 12 volts while cranking and with the key in the run position. Disconnect battery
before proceeding with any work to the vehicle.

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PARTS IDENTIFICATION
ITEM #
IMAGE
DESCRIPTION
QTY
SERVICE P/N
NOTES
1
Bosch Wide Band
Oxygen Sensor
1
554-155
Use of leaded fuel will degrade sensor.
Prolonged use will require periodic
replacement.
Mounting procedure below is critical for system
performance
2
Clamp-on Oxygen
Sensor Bung
1
534-58
Requires 3/4” hole to be drilled
Mounting procedure below is critical for system
performance
In order to help prevent condensation in the
exhaust from damaging the sensor, ensure
that the sensor is installed with at least 10
degrees of vertical angle.
3
Coolant
Temperature
Sensor
1
543-120
3/8” NPT Threads – Adapters to ½” NPT are
available
Must be installed in a coolant passage in either
the intake manifold or cylinder head. Do not
install in thermostat housing.
4
Sniper EFI
Throttle Body
Assembly
1
N/A
4500 Flange Sniper EFI Throttle Body
Includes ECU, fuel injectors, Manifold Air
Pressure (MAP) sensor, Throttle Position
Sensor (TPS), Manifold Air Temp Sensor
(MAT), and an Idle Air Control Valve (IAC)
5
Air Cleaner
Gasket
1
Gaskets for mounting throttle body to intake
manifold
6
Open & 4 Hole
Flange Gaskets
1
7
3.5” Touch
Screen Controller
1
553-115
Includes harness to connect directly to CAN
connector
8
Output Harness
1
558-491
Mates to Input/Output connector on Main
Wiring Harness and can be used for A/C
Shutdown, Electric Fan #1 Output, and/or
Electric Fan #2 Output.
9
Main Harness
and Ignition
Adapter
1
558-490

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PREPARING THE THROTTLE BODY FOR INSTALLATION
If the Sniper EFI will be used on a N/A engine, no changes need to be made to the throttle body.
Draw through Supercharger Applications: When using the Sniper EFI on a draw through boosted application (I.E.
positive displacement blower such as an 8/71), the throttle body must be converted to read manifold pressure from a
remote source that sees manifold pressure. To do this, remove the 1/16” NPT plug nearest the wires on the front of
the throttle body. Thread in a 1/16” NPT barbed nipple. Next, install the supplied 10-32 set screw into the machined
port on the bottom of the throttle body. It is also recommended to take a small punch and peen the casting around the
set screw in 2-3 places. The installation of this set screw is critical to system operation. Failure to do so will cause
false MAP sensor readings.
THROTTLE BODY INSTALLATION
1. Start by labeling all vacuum lines for easy identification, i.e. brake booster & vac advance for distributor. If any
lines appear damaged, now is the time to replace them. Next, remove the carburetor, clean the gasket mating
surface, and install the provided intake flange gasket on the intake manifold.
2. Place the Sniper EFI throttle body on top of the new flange gasket on the manifold. Using the correct length carb
stud and nuts, tighten the Sniper EFI throttle body down progressively in a “criss-cross” pattern (60-80 in.lbs.).
3. Install the throttle linkage to the Sniper EFI throttle body. Be sure to check for any binding conditions and correct
before proceeding. Poorly routed throttle cables & linkages can cause throttle pedal issues. The Sniper Stealth
4500 ships with the unit with a 1:1 throttle linkage. If desired the link between the secondary and primary linkage
levers can be moved to different holes on the primary lever. If the position is changed, the customer must
change settings in the calibration. See section “Sniper Setup” for directions how to change this.

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OXYGEN SENSOR INSTALLATION
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. If disconnecting AIR
pump, check with local ordinances for the legality of this procedure in your area.
Your vehicle may already have an O2 sensor bung welded into the exhaust. This bung location needs to be verified
before using it with the Oxygen sensor included in the Sniper EFI system. Ideally the bung will be 6-10 inches after the
collector for a true reading of all cylinders and have a minimum of 18” length past the sensor location. If the vehicle is
equipped with a catalytic converter, the bung must be between the engine and the catalytic converter. The bung also
must be on the top side of the tube so moisture cannot collect on the oxygen sensor. If there is an acceptable bung
already present, go ahead and tighten the oxygen sensor supplied with your Sniper EFI in the bung. If there is not an
acceptable bung already in the exhaust, please plug all poorly placed bungs and follow the following instructions for
the included Clamp-On O2 bung.
If needed, Hooker Blackheart offers different diameter Clamp-On O2 Bung kits:
2.25” Diameter: 71014303-RHKR
2.50” Diameter: 71014302-RHKR
3.00” Diameter: 71014301-RHKR
1. Locate a position for the oxygen sensor as close to the engine as possible. 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. If you have long tube headers, mount the sensor approximately 6-10” after the
collector. You must have at least 18” of exhaust pipe after the sensor.
2. If your vehicle has catalytic converters, the oxygen sensor MUST be located between the engine and the
catalytic converters. It is also CRITICAL that the oxygen sensor is NOT installed in the bottom of the exhaust
tube. This will help prevent condensation in the exhaust tubing from entering the sensor. The clamp-on kit
installation requires a 3/4 hole to be drilled in the exhaust system. Refer to main installation manual for more
details. NOTE: Verify that the O2 cable is supported correctly and away from heat sources such as the
exhaust. If the O2 cable has melted it is not something fixed under warranty and will require the
unit to be sent back to Holley to be repaired at customer cost.
3. Ensure the location for the sensor is at the angle in Figure 1. This will help prevent condensation in the exhaust
tubing from entering the sensor. The sensor can be mounted on either side of the tubing.
Figure 1
4. Mark the center of the casting on the exhaust tube and drill a 3/4" hole. Deburr the hole after drilling (Figure 2).
Figure 2
5. Place the gasket on the tube (Figure 3), then the casting on the tube (Figure 4). Slip a clamp on one side and
lightly tighten. Slip the second clamp on and lightly tighten (Figure 5). It is necessary to use a small amount of
anti-seize on the threads of the T bolt clamps to prevent thread damage.

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Figure 3 Figure 4
Figure 5
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.
COOLANT TEMPATURE SENSOR INSTALLATION
Install the Coolant Temperature Sensor into a 3/8” NPT coolant passage in either the intake manifold or cylinder head.
Do not overtighten or damage to the cylinder head or intake may occur. It is best to drain thesome of the coolant before
the sensor is installed. Use thread sealer or a small amount of thread tape. Do not install the sensor in the thermostat
housing, or in an area that will not see a constant flow of coolant.

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FUEL SYSTEM CONNECTIONS
Connect fuel feed and return hose. It is mandatory to use an external fuel pressure regulator and feed both front and
rear fuel injector covers. Holley 12-848 or 12-851 are the recommended bypass fuel pressure regulator based on
how much HP the application makes. Reference Figure 3 & 4 for plumbing diagrams and recommended fuel system
components.
NOTE: Fuel pressure should be checked on the inlet fuel line before initial start up during the fuel pump prime. We
recommend Earl’s Part Number 100187ERL (0-100 psi Liquid filled gauge) & AT100199ERL (-6AN Gauge Adapter) to
check fuel pressure.
Fuel Fitting Overviews
HP Rating
Fuel Pump
Regulator
Pre
Filter
Post
Filter
Feed Line
Size
Return Line
Size
Up to 800 HP
12-1600
12-848
162-570
162-572
-6 AN
-6 AN
800 HP to 1000 HP
VR1 12-1500
12-851
162-577
162-575
-8 AN*
-8 AN*
Greater than 1000 HP
VR2 12-3000
12-851
162-577
162-575
-8 AN*
-8 AN*
*Use 3/4”-16 Male O-Ring to -8 AN Male Fitting, PN AT985008ERL, on the Sniper Throttle Body, Purchased Seperately
DANGER! Take precautions to ensure that all fuel components are away from heat sources, such as the
engine or exhaust pipes. A fire or explosion hazard could cause serious injury or death!
DANGER! Before disconnecting or removing fuel lines, ensure the engine is cold. Do not smoke.
Extinguish all open flames. An open flame, spark, or extreme heat near gasoline can result in a
fire or explosion causing property damage, serious injury, and/or death.
DANGER! Never get under a vehicle supported only by a jack. Serious injury or death can result from
vehicles falling off of jacks. Before working underneath a vehicle, support it solidly with jack
stands.