Stalling Problem

[Floordry]

totaled brought his car over- jumped the pump direct to battery- got 10PSI on fuel press gauge hooked to fuel rail. Going to get a new fuel pump to replace this one and will report back- any thoughts would be great

[Floordry]

So just for the heck of it, we put the old fuel pump back in, jumped it direct to batt, got 45 PSI on gauge, car started up after a few seconds of cranking. This morning it also started after a few seconds of cranking, but stalled- started right up again- going to go for a drive here in a few to see what happens.....

[Floordry]

So now we are back to the original discrepancy- car cranks about 10-15 seconds before starting, but starts and idles- sometimes it dioes, sometimes not- went for a drive, engine died about 40 MPH, pulled over, started up, drove on, all other indicators/gauges appear normal.

CPS replaced, idle air control valve replace, throttle position sensor replace, MAF Cleaned, Fuel Press reg replaced, 45 PSI fuel pressure at rail. Long cranking could come from check valve in fuel pump, not concerned with long cranking at this time.

Any more thoughts?

[Archon]

Is the pump still direct wired? If you can, get an extension cable for the fuel pressure tester, so that you can tape the tester to the windshield and observe the pressure when the car dies.

[Floordry]

Not still direct wired- I'll try to get an extemsion- is this an auto parts store item or a custom hyd shop manufacture?
It occassionaly dies in the drive way just after starting, but starts right up and seems to run. I'm going to put on jacks and bang the cat to see if it rattles - while it is cold.

I'll post if I can get an extension- are we trying to identify if the pump is bad/overheating or it is in fact an electrical problem with this test?

[Archon]

I believe that most have made their own, but I have seen some here and there on the internet. However, I don't recall where.

If it is stalling in the driveway, check the pressure there when it stalls. Does it drop? If so, you may want to either bypass, or purchase a replacement for the fuel pump control module.

[Floordry]

Where is the fuel pump control module located? is it the piece hidden on the pass side truck support with a large heat sink?

I believe that most have made their own, but I have seen some here and there on the internet. However, I don't recall where.

If it is stalling in the driveway, check the pressure there when it stalls. Does it drop? If so, you may want to either bypass, or purchase a replacement for the fuel pump control module.

[madisonguy]

I am having the same issue, but I am several steps behind you. Mine is very recent and so far have only replaced the fuel filter and cleaned the MAF sensor with no luck either time. I am interested in your results. I have not noticed the issue with the boost gauge, but will check that one out too. Keep me posted with how things turn out for you. If I get any results here, I will be sure to post. Thanks.

[Archon]

Where is the fuel pump control module located? is it the piece hidden on the pass side truck support with a large heat sink?

That sounds like it.

[Floordry]

Well, spent the $300 at AZ for a fuel pump assy- the whole thing this time- put it in, turned key- got 45 PSI at rail- car started in less than 2 secs. Went for a 20 mile drive- ran great, got lots of boost when needed, no stalling, no stumbling, great idle. I'm calling this repair complete.

[Floordry]

And thanks to everyone for all their support and technical info.

[Archon]

Glad that you got it fixed.

[madisonguy]

Sorry to add on to someone elses thread. I will start a new one if you want me to. I just had all of the same symptoms (other than the boost seems to be fine) and thought this would be a good place ask another question.
Is the fuel pressure supposed to vary with engine rpm? I turned key to on, fuel pressure at 8 psi. Started vehicle and ran at idle with fuel pressure at 8psi. Revved up engine a few times, fuel pressure 40-45. Return to idle, fuel pressure at 40-45. During revving, fuel pressure goes up with rpm, varies between 40-55 (looks like a tach during revving).
If this is not normal, would this be fuel pump or regulator?
Thanks

[Archon]

I'd suggest a new thread, and we'll deal with your specific problem there.