thatsupnow

Hey guys I've got an issue with my 91 Z, so I just buttoned up the rest of my build and wanted to get it running. It's a forged 370 LS 80mm turbo, 4l80e with a Holley Dominator controlling it. I'm also running a Racetronix fuel system dual 340 in tank pumps. So I got all my wiring where it needed to be for the dominator I used all the same conect points I used with my HP system I had on the car years ago.

I finally go to turn the key and I've got power but that's it, there's no crank, and no fuel pump prime. So I pull the starter relay and jump the 2 thick wires together and now the motor cranks, but still no fuel pump prime. I'm still using the factory relay and wiring and just hook my Holley trigger wire up to my grn/wht wire on the factory stuff just like I did with my HP unit. I pull the bulkhead from under the car and test that and no power. I've got power at the orange wire on the relay but I guess that's as far as it makes it. I've even jumped the orange wire to grey wire and checked the rear bulkhead and nothing.

Anybody have any ideas what I should try next?? Granted the car is 30 years old now so if the consensus is to just replace wiring then that's what I'll do. Just a little bummed out as it's taken me like 5 years to get to this point.

Oh and I did take that firewall connector apart and it was pretty black in there but looked like some kind of grease?? IDK but I'm running out of ideas quick and I'm all ears for any new ideas you guys may have. Thanks guys have fun

vorteciroc

I am going to try and help you with the start of your thread:

@thatsupnow
"Hey Guys, I have a Turbocharged Gen-3 SBC, 4L80E swapped 1991 Z28 that is controlled by a Dominator Holley EFI-System.
Also the Car has dual In-Tank Racetronix 340 Electric Fuel-Pumps.

I am trying to finish things up, and attempted to start the Engine.
The Ignition turned on... but the Engine did not crank, and I did not hear the Electric Fuel-Pumps prime.

I removed the Original/ Stock Starter-Motor Enable-Relay to jump the Circuit.
When doing so, the Starter-Motor did crank.

I have the Holley EFI Dominator wired to trigger the Original/ Stock Electric Fuel-Pump Relay.



Instead of the Original/ Stock PCM triggering the Electric Fuel-Pump Relay via the Dark-Green with White-Tracer Wire...
The Holley EFI Dominator now does so.

There is 12V+ present at the "A" Terminal of the Electric Fuel-Pump Relay Connector (Orange Wire).
So I removed the Electric Fuel-Pump Relay to Jump the Circuit (Orange Wire to Grey Wire)...
However the Electric Fuel-Pumps did not turn on.

Does anyone have any ideas, as what I should try to do next...
What to look at, and what to test?"

vorteciroc

Well, first off...
The Starter-Motor should have cranked the Engine; so some time needs to be spent looking at Wiring.
Do you know if the original/ stock VAT-System is operational?

Second, the Electric Fuel-Pumps not turning on...
I would make certain that there is a proper Ground-Connection for the Pumps.

Then I would try to power the Pumps directly.
No Relay, No Dominator... just apply 12V+ and 12V- directly to the Electrical-Connector for the Pumps.
I like to keep a Motorcycle Battery for simple 12V Testing (they are very small and light-weight).
Should the Pumps not turn on... then the Pumps are not good anymore.

Post a Reply when you have gotten this far.

thatsupnow

I've never done anything with the vats system on the car, I didn't touch it when I had the HP and it started up just fine. I checked the grey wire for continuity and found there was a break, replaced and now have 12v to the back. I checked my pump to ground and was good on that. The Racetronix relays aren't being triggered at all for whatever reason. When I pulled their relay and jump pin 30 to 87 the pumps fired right up. I did manage to fire up the motor but I've got fuel level gauge working and it's a brand new sender. I'm now leaning towards the Racetronix harness being wired up wrong

Another question I have is,

Can those bulkhead connector behind the rear seats go bad?? Mine has a lot of rust/corrosion coloration