No start unless power is ran to the green fuel pump wire.

[LSX55]

I've changed the fuse near the relay, but my engine will only start if I feed power to the green fuel pump output wire. What am I missing?

[Danny Cabral]

I've changed the fuse near the relay, but my engine will only start if I feed power to the green fuel pump output wire. What am I missing?

1) Fused +12V & Switched +12V:
Since the fuse is fine, I'd start troubleshooting the system relay. Have you performed a TPS Autoset?
Also, ensure the Switched +12V red/white wire (pink wire - Sniper EFI) is powered in the "Run" and "Crank" key positions.
The ignition switch must have a wire that's powered in "run" and "crank" key positions leading to the ignition system.
The ignition switch can't start the engine, if there isn't a circuit that's powered in the "Run" and "Crank" key positions.
The easiest way to find this wire, is to look at the wiring schematics in a factory shop manual or even a Haynes manual.
As a test to determine what's at fault, connect the Switched (keyed) +12V wire directly onto the battery positive terminal.
https://www.msdperformance.com/suppo...s/#EngineRunOn (MSD Troubleshooting - Engine Run-On)
http://forums.holley.com/showthread....5760#post45760 (Scroll down to "Typical No-Start Checks".)
http://forums.holley.com/showthread....4352#post44352 (ECU/Main Power Harness Troubleshooting Post)

2) System Relay Troubleshooting:
Troubleshoot the system relay & its wiring. The system relay's coil is grounded at terminal #85 by the loose black wire.
The ECU's J1A-A2, (22 AWG red wire) energizes +12V the system relay coil at terminal #86,
during the 5 second Fuel Pump Prime time, when cranking, and when the engine is running.
There's a fuse next to the system relay, that powers the relay (14 AWG red wire) at terminal #87.
The system relay activates the fuel pump, and powers the fuel injectors (& ignition coils - LSx, MOD & HEMI) from terminal #30.
The ECU pulses the ground side of the injectors to spray fuel. Which of the above actions isn't happening?
http://documents.holley.com/techlibr...10555rev17.pdf (Holley EFI Wiring Manual - Sections 2.1 "Pin-Outs" & 13.0 "Wiring Appendix")
https://forums.holley.com/showthread...7668#post87668 ("Test Relay" for troubleshooting/diagnosis.)

3) Injector Wiring Troubleshooting:
You can use an injector noid light (LINK), an injector probe (LINK), or even a long screwdriver used as a stethoscope (placed between
an injector and your ear, listening to each working injector). Ensure the spark plugs aren't fuel saturated and therefore won't fire.
An injector noid light only indicates if the circuit is active or dead; it's just a convenient (quick connect) test light.
It doesn't indicate if the +12V or Ground pulse is the problem; you'll need a multimeter (volts) to determine this.
If you're working alone, use a remote starter switch (LINK) to jump the starter and crank the engine (key-on).
To check for constant +12V while cranking, connect the positive multimeter probe on the injector connector +12V pin, and the negative multimeter probe on battery −.
To check for pulsed Ground while cranking, connect the negative multimeter probe on the injector connector ground pin, and the positive multimeter probe on battery +.
Another possibility, is if one of the fuel injectors is shorted out and incapacitating the ECU's injector drivers. Try unplugging all fuel injectors and test one connector.
http://documents.holley.com/techlibr...10555rev17.pdf (Holley EFI Wiring Manual - Section 13 "Wiring Appendix", Figure 18, Page 31)
http://forums.holley.com/showthread....4352#post44352 (ECU/Main Power Harness Troubleshooting Post)

The Terminator, HP & Dominator ECUs are compatible with both high & low impedance fuel injectors.
The Terminator X & X Max ECUs are only compatible with high impedance fuel injectors.

HIGH IMPEDANCE INJECTORS — Most injectors can be divided into two major categories: high impedance 12 to 16 Ohms and low impedance 1.2 to 4.0 Ohms. The high impedance injectors are used with ECUs that are designed with saturation drivers. The advantage of using saturation drivers is that the currents running through the ECU circuits and the injectors are relatively low thus generating less heat. The disadvantage of saturation drivers is that the driver has a slower response time, which could affect the full utilization of such a system at very high engine RPM. LOW IMPEDANCE INJECTORS — The low impedance injectors are designed to be run with an ECU that employs peak & hold drivers (also called current sensing or current limiting drivers). The current ratio (peak to hold) is generally 4:1, and the most common drivers available are 4A peak/1A hold or 2A peak/0.5A hold. The peak current is generated to overcome the inertia of the closed valve and once the valve is open the driver cuts down to 1/4 of the peak current to hold the injector open until the end of the metering event. Low impedance injector designs are mostly used in high flow applications.

4) Multiple Sensors Display Erroneous Values:
This is sometimes a bad ground, or shorted, chaffed or burnt wiring. This may be caused by a defective sensor (since some share +5V reference and all share a common ground) or a failed actuator (IAC motor, fuel injector, etc.). Disconnect each sensor and actuator one at a time, while watching the Data Monitor (laptop "Online" with ECU). If one unplugged sensor restores the system to proper sensor values, then that's the culprit. Also, try completely disconnecting the battery for 20 minutes (or 2 hours for some severe faults), this "resets" some unusual ECU issues.
https://forums.holley.com/showthread...ensor-Problems (Related Forum Thread - Read This!)

Originally Posted by Danny Cabral • EFI Software Problems: Often times, when EFI software related functions don't work properly, it's caused by a corrupted software download/installation. I suggest completely removing the Holley EFI software from the "Control Panel", "My Documents" (Holley folder) and the "C:Drive" (Program Files, Holley folder) and install a fresh EFI software download. Save your Global Folder somewhere. • ECU Firmware Problems: Conversely, often times, when actual ECU related functions don't work properly, it's caused by a corrupted ECU firmware installation. As a last resort, you can try reflashing the ECU firmware version (LINK). The ECU firmware is in with the software download (LINK). Also, try completely disconnecting the battery for 20 minutes (or 2 hours for some severe faults). This "resets" some unusual ECU issues.

Originally Posted by Danny Cabral Crank & Cam Sensor Wiring Tips: The 10-pin Ignition Connector has one "Chassis Ground" (loose black wire ground) and two "IPU Grounds" (clean ECU ground). Don't use "Chassis Ground" to ground an ignition module (or crank & cam sensors). It's quick & easy to move the ignition module ground wire from (cavity) pin D "Chassis Ground" to pin C or G "IPU Ground", where it should be. If you don't have the actual Metri-Pack terminal release tool, a "safety pin" will work. It just needs to be a stiff wire between .030"-.035" in diameter to release the terminal tab. Then reopen (bend) the terminal tab before reinsertion, so it will clip (lock) into the cavity. http://www.whiteproducts.com/removal_tools.shtml (T-6 Micro Terminal Release Pick Tool) Also, don't use (cavity) pin E "Switched +12V" from the 10-pin Ignition Connector, to power an ignition module (or crank & cam sensors), unless you've modified the wiring source to connect from pin B20 - EST 12V Output (P1B ECU Connector). This LINK explains why & how to do it. http://documents.holley.com/techlibr...10555rev17.pdf (Holley EFI Wiring Manual, Sections 2.1 "Pin-Outs" & 13.0 "Wiring Appendix")

Originally Posted by Danny Cabral Clamping a timing light on each cylinder, works well for misfire detection (watch for consistent flashing). Test drive it with a timing light taped to the windshield if necessary. Ignition misfires cause false lean spikes. Sometimes people are shocked at what they see. Also, ensure all the fuel injectors are operating. You can use an injector noid light (LINK), an injector probe (LINK), or even a long screwdriver used as a stethoscope (placed between an injector and your ear, listening to each working injector). Other less definitive methods for MPFI applications, include infrared temp gun readings on header primary pipes, or a wet rag on header primary pipes. However you do it doesn't matter, just confirm combustion on all cylinders.

Originally Posted by Danny Cabral I've never used the ECU's fuel pump trigger wire to directly power the pump (even if it is less than 10 amps). I've always used a separate relay (shown below) because that green wire is still only 14 AWG. The 2nd fuel pump relay is used so the fuel injectors aren't subjected to the pump's amp draw. It's only a 20 amp fuse and it also feeds power to the fuel injectors (& ignition coils - LSx, MOD & HEMI). I prefer to use 10 gauge wire due to its long length, especially for high output race pumps. Simply use the green fuel pump wire (+12V) to trigger your additional fuel pump relay's coil (+) terminal # 86. https://www.holley.com/products/fuel...s/parts/12-753 (Holley 12-753 Fuel Pump Relay Kit) http://documents.holley.com/199r10059.pdf (Holley 12-753 Fuel Pump Relay Kit Instructions) https://www.holley.com/products/fuel...arts/30-199QFT (Quick Fuel 30-199QFT Fuel Pump Relay Kit) https://www.holley.com/products/fuel...s/parts/40100G (Mr. Gasket 40100G Sealed Relay Kit) https://www.summitracing.com/parts/pco-5593pt/overview/ (Pico Wiring 5593PT Sealed Relay Kit) Delphi Metri-Pack 630 Pull-To-Seat female terminals for retrofitting to a sealed relay socket connector: #12033997 10/12 AWG (3.0 mm²), #12066614 14/16 AWG (2.0-1.0 mm²), #12020156 18/20 AWG (0.80-0.50 mm²)