Expert Needed: Fuel Pump signal NOT coming from ECM - hair pulling!
Forum: C3 Electrical, Body and Interior
Hi, Bought a 1982 with a fuel pump signal problem... if I jumper the relay pump works and engine pops off!
What I have tried so far:
- confirmed orange wire by battery (20amp fuse) is ok
- replaced ecm same condition
- replaced the fuel pump relay
Can somebody tell me where to look for possible issue with wiring? I have probed to connector on ecm and no signal
also confirmed that ground has continuity to ecm.. Please help 🤒
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Moderator
Without looking at a wiring diagram. or knowing what specific code(s) you have, I would venture to guess you have an oil pressure sending unit problem. The ECM looks for oil pressure to ground the fuel pump relay, as well as an ignition signal. One or the other...or both, can cause the pump to play dead.
Joel Adams
C3VR Lifetime Member #56 
My Link 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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Thank you Joel! been trying everything, and it was tough to track down! ended up being corroded fuse for ECM power! what the hell LOL My journey just beginning with this one 😂
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Moderator
It's always something silly, right? lol
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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