LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Fuel pressure issues. LT1

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Old 07-20-2008, 05:09 PM
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Default Fuel pressure issues. LT1

1997 camaro z28 6 speed.

Somewhere, the car is losing fuel pressure, very quickly.

41-47 psi is about where it should hold*as per shoebox's website* with the pump primed, ignition on, car not running.

I prime my pump, i get nothing. I prime my pump 6 times, i get 7 psi roughly.
I attempt to start the car, it takes ALOT of cranking, eventually the needle starts to go up as it builds pressure SLOWLY and then it fires. Jumps around from 10-25 psi while the car coughs and almost dies out, then eventually goes to and holds 45psi at idle(This is normal pressure at idle at least lol). Revving the motor yeilds a 2-3psi drop in pressure with no load on it. At WOT the pressure should be again around 41-47 psi. Mine drops to 28 psi and holds there roughly.

When i shut the car off, the pressure drops almost instantly. Doesnt hold any pressure. Also a few times i could hear a hissing noise at the back of the car by the tank. So i have a feeling something is amiss here. Either the pump is going bad, or i have a leak in the line somewhere. Which im assuming as of the hissing noise. So first thing is first, im going to change the fuel filter. Then do a retest and go from there.

Opinions welcome, thanks

P.S What kind of drop in power can be expected with a 15-18 psi drop in pressure?
Old 07-20-2008, 05:53 PM
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change the fuel filter.. possibly the pump
Old 07-20-2008, 08:56 PM
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I ordered the racetronix pump kit from there website. Theres no way in hell its leaking down that fast through injectors, theres no leaks on the ground.Fuel filter wouldnt make it not hold pressure unless it was leaking in which case it would be on the ground.
Ordered the pump and wiring upgrade and will replace the fuel filter at the same time. Going in through the trap door method
Old 07-21-2008, 09:25 AM
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Originally Posted by 97lt1camaro
I ordered the racetronix pump kit from there website. Theres no way in hell its leaking down that fast through injectors, theres no leaks on the ground.Fuel filter wouldnt make it not hold pressure unless it was leaking in which case it would be on the ground.
Ordered the pump and wiring upgrade and will replace the fuel filter at the same time. Going in through the trap door method
Should solve your problems. The Racetronix kit is a nice kit. I too did the trap door method.
Old 07-22-2008, 03:45 PM
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What is the trap door method??? I need to put a new pump in my 95 Hawk and am going with the full racetronix kit. Can it be done without dropping the tank?
Old 07-22-2008, 03:54 PM
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[QUOTE=Hawk465;9786178]What is the trap door method??? I need to put a new pump in my 95 Hawk and am going with the full racetronix kit. Can it be done without dropping the tank?[/QUOTE

^^What he said^^
Old 07-22-2008, 04:01 PM
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Two options:

Option A
Dropping the tank:
https://ls1tech.com/forums/fueling-injection/938621-fuel-pump-dropping-tank-write-up.html

Option B
Trap door method:
http://www.geocities.com/formulapower2/fuelpump.html

Here's a thread debating the two:
https://ls1tech.com/forums/showthrea...thod+trap+door



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