Fuel pressure will not hold or go over 15 psi
#1
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Car: 87 iroc and 88 k2500 tbi truck
Engine: l98 and lo5
Transmission: 700 r4's babby
Fuel pressure will not hold or go over 15 psi
I have a holley 670 tbi part 502-6 and a wallbro 195 pump that is about 2.5 years old i changed the fuel regulator diaphragm and even with the screw bottomed out it will not go over 15 psi and under load it dips to 11 psi i am looking for about 18 psi and holding. I have no clue where to go now. if i had the stock pump I know that i would need a new one but I am running a good pump unless it has started to fail.
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Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
Re: Fuel pressure will not hold or go over 15 psi
Bottoming out the screw will close off teh return passage, which should cause teh fuel pressure to soar to around 90 PSI. It sounds like the pump may be bad or there may be a leak in the tank on the supply side. As a test, get a set of hose pliers and slowly close off the return line. If teh pressure does not rise (dont let it go higher then 40 PSI), then there is an issue. Also, the stock replacement holley TBIs only could support up to around 15 PSI. Youll need a stronger spring to go higher.
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Car: 87 iroc and 88 k2500 tbi truck
Engine: l98 and lo5
Transmission: 700 r4's babby
Re: Fuel pressure will not hold or go over 15 psi
well i have no leaks and i pulled the pump to check inside the tank and its ok so you think my pump is shot. can I use a tpi pump as a replacement
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Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
Re: Fuel pressure will not hold or go over 15 psi
If it cant make over 15 PSI with the return blocked then its likely hosed. The TPI pump will also work fine so long as your not getting too crazy with the demand. With the stock holley injectors, though, you should be fine.
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