low fuel pressure at idle
04-27-2009, 09:58 PM
#1
low fuel pressure at idle...bad FPR? when my car is at idle my fuel pressure is at 32psi. I have changed the fuel filter and the fuel pump. My car is a 93 so my question would be what kind of aftermarket FPR would be my best selection and or would just replacing it w/ a factory one work? I am doing a cam swap right now (230/236) with LS7 lifter 1.6rr and matching springs. So i will already have the fuel rail and intake off.
Any advice will help out.
Any advice will help out.
Last edited by litch2004; 04-27-2009 at 11:30 PM.
04-27-2009, 11:55 PM
#2
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I have a similar problem with mine idling at around 35 psi. I don't know whether to go with an adjustable fuel pressure regulator or a stock one. My fuel system is all stock.
04-28-2009, 07:43 AM
#4
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Are you disconnecting the vacuum port when checking it? The pressure will change (increase) a good 6-8 lbs., make sure your doing this when checking the FP, Now if your looking for a decent inexspensive FPR, i got one from O'Reillys, it was cheaper then the factory (non adj.) unit, it worked fine, never had an issue with it, plus it came with a good warr.
04-28-2009, 11:09 AM
#6
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41-47 key on not running
at idle, should decrease 3-10 psi.
so anywhere between 31-44 at idle.
this is according to my chilton manual, 1997 and earlier. 1998+ has higher numbers.
is there a problem with the car, or do you just feel its too low? everything you said shows a proper pressure holding fuel system.
at idle, should decrease 3-10 psi.
so anywhere between 31-44 at idle.
this is according to my chilton manual, 1997 and earlier. 1998+ has higher numbers.
is there a problem with the car, or do you just feel its too low? everything you said shows a proper pressure holding fuel system.
Last edited by trippinholyman; 04-28-2009 at 11:14 AM.
04-28-2009, 11:36 AM
#7
As stated, disconnect the vacuum line to the fuel pressure regulator and test your fuel pressure. You also should test if your fuel pressure holds while under load at high rpms. If it checks out, you're good.
Another thing, don't waste your money on any adj fpr's. Fuel delivery is computer controlled.
Another thing, don't waste your money on any adj fpr's. Fuel delivery is computer controlled.
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04-28-2009, 07:30 PM
#8
41-47 key on not running
at idle, should decrease 3-10 psi.
so anywhere between 31-44 at idle.
this is according to my chilton manual, 1997 and earlier. 1998+ has higher numbers.
is there a problem with the car, or do you just feel its too low? everything you said shows a proper pressure holding fuel system.
at idle, should decrease 3-10 psi.
so anywhere between 31-44 at idle.
this is according to my chilton manual, 1997 and earlier. 1998+ has higher numbers.
is there a problem with the car, or do you just feel its too low? everything you said shows a proper pressure holding fuel system.
Thanks for your help
04-29-2009, 03:31 AM
#9
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The PCM will only adj. the fuel tables so much, after that your on your own, i bought my adj. reg. because to my surprize it was cheaper then the non-adj. unit, but i found that setting the pressure higher slowed my car down (MPH) at the track on back too back runs, so the PCM couldn't currect the tables in a 8-10 lb. difference, the non-adj. unit was 76.00, the adj. unit was 55.00, plus it was fun playing with the pressure to see if it helped or hurt.
