Fuel Pressure Problem
11-27-2010, 05:50 PM
#1
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Fuel Pressure Problem Know this is FI fourm but its somewhat related
Trying to get my ls3 swap started, when i turn on the key the pump primes, fuel pressure gauge on rail goes up to 48 then as soon as the pump shuts off drops down to 0-10 within 2 secs. A1000 pump, fuel cell in trunk, -8 feed line into a y then goes into each rail and the FPR(boost ref) is in between rails with a -6 return to cell. I blocked off the return on the FPR and it still dosent hold pressure. My vac port on the FPR also does not have fuel comming out of it. The fuel filter is also a brand new big aeromotive inline one. Theres no fuel leaking anywhere. Anyone have any ideas? Im going nuts!!!
Trying to get my ls3 swap started, when i turn on the key the pump primes, fuel pressure gauge on rail goes up to 48 then as soon as the pump shuts off drops down to 0-10 within 2 secs. A1000 pump, fuel cell in trunk, -8 feed line into a y then goes into each rail and the FPR(boost ref) is in between rails with a -6 return to cell. I blocked off the return on the FPR and it still dosent hold pressure. My vac port on the FPR also does not have fuel comming out of it. The fuel filter is also a brand new big aeromotive inline one. Theres no fuel leaking anywhere. Anyone have any ideas? Im going nuts!!!
11-27-2010, 06:52 PM
#2
Know this is FI fourm but its somewhat related
Trying to get my ls3 swap started, when i turn on the key the pump primes, fuel pressure gauge on rail goes up to 48 then as soon as the pump shuts off drops down to 0-10 within 2 secs. A1000 pump, fuel cell in trunk, -8 feed line into a y then goes into each rail and the FPR(boost ref) is in between rails with a -6 return to cell. I blocked off the return on the FPR and it still dosent hold pressure. My vac port on the FPR also does not have fuel comming out of it. The fuel filter is also a brand new big aeromotive inline one. Theres no fuel leaking anywhere. Anyone have any ideas? Im going nuts!!!
Trying to get my ls3 swap started, when i turn on the key the pump primes, fuel pressure gauge on rail goes up to 48 then as soon as the pump shuts off drops down to 0-10 within 2 secs. A1000 pump, fuel cell in trunk, -8 feed line into a y then goes into each rail and the FPR(boost ref) is in between rails with a -6 return to cell. I blocked off the return on the FPR and it still dosent hold pressure. My vac port on the FPR also does not have fuel comming out of it. The fuel filter is also a brand new big aeromotive inline one. Theres no fuel leaking anywhere. Anyone have any ideas? Im going nuts!!!
I had a Racetronix/Walbro 255, it held pressure. I now run a Magnafuel EFI Pro Tuner 750, it will prime and then drop to 0 unless you actually start the car. I called Magnafuel concerned about it and they said thats just how they are supposed to work, I bet that A1000 is the same way.
11-28-2010, 12:23 AM
#3
x2 though I would also make sure you don't have a stuck injector. Not likely but can happen and if enough fuel flows into a cylinder you can hydralock the motor when starting and bend a rod (ask me how I know). Better safe than sorry. If everything checks out ok and you don't like how the pressure bleeds down aeromotive makes a check valve that you can add to the pressure side of the pump to keep from bleeding down.
11-28-2010, 01:11 AM
#4
if I recall, the A1000 has an internal bypass poppet. Therefore after it primes or it is shutoff, it will bypass the pressure back to tank resulting in guage/pressure drop.
I had this problem once, the diaphram in the regualtor busted, which fed fuel back into intake via boost reference line, needless to say, when I started car up next moring I wound up with a snapped connecting rod!!! double check your vaccuum/boost ref. hose to be sure !!!!
I had this problem once, the diaphram in the regualtor busted, which fed fuel back into intake via boost reference line, needless to say, when I started car up next moring I wound up with a snapped connecting rod!!! double check your vaccuum/boost ref. hose to be sure !!!!
