Is it possible that fuel pump primes but doesn't flow?
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Joined: Mar 2011
Posts: 114
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From: Chicago, Il
Car: 1986 Iroc Z28
Engine: 305 TPI
Transmission: 700R4
Is it possible that fuel pump primes but doesn't flow?
Just did a tpi to Carb swap and now the oem fuel pump doesn't appear to flow fuel when running, I hear it prime and if I fill the carb bowl it'll run until the bowl goes dry. Fuel pressure gauge that I can't confirm if correct is reading 0psi. Not sure if bad pump or if additional wiring is needed to keep it flowing when running due to the swap? ECU is plugged in.
Edit: it is possible, when swapping to Carb you need to run 12v hot wire to the green wire on the pump relay, I did this and everything works! Apparently the ecm primes but doesn't do anything after that. If you use the wiper motor like everyone says to, good luck...had to have the wipers on to get power.
Edit: it is possible, when swapping to Carb you need to run 12v hot wire to the green wire on the pump relay, I did this and everything works! Apparently the ecm primes but doesn't do anything after that. If you use the wiper motor like everyone says to, good luck...had to have the wipers on to get power.
Last edited by mdtoren; Apr 10, 2016 at 10:11 PM. Reason: New info
Supreme Member
Joined: Jun 2011
Posts: 2,036
Likes: 6
From: knoxville tn
Car: 86 IROC
Engine: 5.0 TPI
Transmission: 700-R-4
Axle/Gears: 2.73 open
Re: Is it possible that fuel pump primes but doesn't flow?
what an impossible can of worms you have there, people dont realize chucking their TPI set up for a flintstone tech carb causes ALL SORTS of additional issues. at present i have 3 TPI cars here that the owners tryed to convert to carb and gave up . you guessed it . im putting the TPI back on all of them
Supreme Member
Joined: Mar 2009
Posts: 1,402
Likes: 3
From: Sussex County, NJ
Car: 1994 Z28
Engine: 355 LT1
Transmission: T56
Axle/Gears: 3.42
Re: Is it possible that fuel pump primes but doesn't flow?
Do those cars have a fuel pump cutoff when low or no oil pressure is detected?
It's not a pump issue if it worked prior to the conversion, it's a wiring issue.
It's not a pump issue if it worked prior to the conversion, it's a wiring issue.
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