Just kinda curious as I am seeing my BLM's sitting at 137 left bank and 140 right. And I am currently having an issue that seems to be Check valve in the fuel pump as I am having hard starts and my pressure immediatly drops to 0 soon as I shut the car off, and the FPR is showing no signs of being ruptured nor are the Injectors leaking. Was wondering if the Fuel pump which shows about 31-32 psi at idle be running lean enough to cause my car to raise the BLM"s like that when im not having really any other issues other than the hard starts and rapid fuel line bleed off?

I do notice coming to a stop my rpms seem to linger around 1300 but drop back to 800 pretty quickly. It had me wondering if I had a vac leak somewhere but I haven't the tools to check that to be sure atm. Scan tool shows nothing of concern but I can't say for sure about Vac. Basically thats what I have to go on as of now.

So... whaddya think?

 

The PCM holds the idle RPM elevated until the car actually stops (VSS = 0).

31psi at idle is low, even with the vacuum compensation line hooked up. But do a complete fuel pressure test.....

1. At idle, pull the vacuum line off (hold your finger over the end to prevent a vacuum leak) - fuel pressure should be in the range of 41-47psi (ideal is 43.5psi).

2. Reconnect the vacuum line, and fuel pressure should drop proportional to intake manfold vacuum - about a 6-8psi drop with a stock cam.

3. Tape the gauge to the outside of the windshield, take it out on the road at max load/RPM. Pressure should not drop below 40psi.

If your pump passes all three tests, the pump and regulator are healthy.

As a point of reference, a 140 BLM means the PCM ishaving to add 9.4% extra fuel. To get a 9.4% loss in fuel flow based ONLY on low fuel pressure, your fuel rail pressure would have to be about 7psi lower than it is supposed to be.

 

Thanks alot for the help Fred


1) Did this and was seeing 41 psi plugging the line with my thumb

2)reconnected it dropped to 31-32 psi

3) was seeing 38-39 psi



The only culprit I really have to point at for my hard starts and line pressure bleed off atm seems to be the Check valve as I tested the FPR for fuel on vac line and the Injectors I pressurized and elavated them over the ports with no drips. Maybe pump is on its way =/.


EDIT: thanks for clearing up the Idle issue, that gives me peace of mind.

EDIT: Also noticed although not drastic, my IAC counts seem to be going up to 42-43 on occassion. I always have understood the norm to be 20-40 at idle. Dunno if a couple over 40 is enough to entertain.