Fuel Pump Issue

Gravy · 05-01-2009

Removed the rewire and ran straight from battery to fuel pump for testing as well to eliminate anything from point A(battery) to point B(Pump). This post IS the cliff notes. I've tried all three pumps i have(Stock, 190 and 255 walbro) in and out of the vehicle, all three give the same results. And the pump works 100% of the time when the ground wire is supplied directly to the pump, but when the whole assembly is bolted down, i get nothing. Positive is fully covered and there are no exposed wires on it. I've got it working as of now, but with only three bolts holding the fuel pump in the back on, with one more holding it down with electrical tape between it and the mounting plate. Remove it, and the electrical tape it's fine. Put the bolt back down with no electrial tape(metal on metal) and i get nothing. I laughed so hard workin on it i started to cry.

Thanks for the idea though, i'll be checking voltage(resistance and ground) soon as i get a volt meter to rule out a bad wire on either the positive or the ground.

munchgsx · 05-01-2009

Have you tried a different sending unit? Did you do your rewire by the book?
Relay triggered by stock power wire.

Gravy · 05-01-2009

I don't have access to another sending unit, but i know the ground from the factory does work, and i have a secondary ground going to the frame of the sending unit as well.

I did the rewire by the book, and it will run now both in stock format, and with the rewire on there. And with the rewire on if i hook up a stock mass i still get the same issues when it acts up, and works both ways when the problem presents itself. I run with a GM maf and when i start it with the stock hooked up, with out metering the air, the relay clicks on and off like it should. When the car is running with only the three bolts holding it down, i can let it idle, rev it up, and it runs just fine. And it would technically work if i didn't mind the smell of gas following me everywhere.

Febo · 05-02-2009

Quote:

Originally Posted by munchgsx

Have you tried a different sending unit? Did you do your rewire by the book?
Relay triggered by stock power wire.

He has a bat relocate to the trunk too so it deff is a grounding issue as we were running power straight to the pump, and also grounding the sending unit straight to chassis or the negative terminal to show that it wasnt the pump. It is deff a weird ground issue, havent touched it with a volt meter yet, but we will tomorrow.

Cliff notes are his stealth is possessed.