Car starts then immediately dies

[Windsor58]

Need suggestions. My car will start, go through the short rev up when it fires off. Then as the rpm drops back down and should go to idle, it dies. It dies at the same point every time. Its like the rev after it catches is open loop and after 3 seconds or so, it drops to a closed loop idle, but thats when it dies every time. Checked everything I could (limited) and finally had it towed to a shop I use. The first time they tried it, it was working normally. It didnt die for them at all! (of course-take it in and it aint broke any more... arghhh).
Any suggestions what could be doing this? I dont believe its fuel. Has 60 psi just before trying to start it. The pressure drops but not abnormally when the starter is engaged. And when I tried pumping the gas pedal to keep it from dying a few times and I could smell fuel so I think the fuel is being pumped through but not ignited when it dies. So, I think its electrical but I dont know what would cut the ignition right after it reved up on start.
Yes, its working ok now (at the shop) but when will it fail again? I'd like to figure it out and fix it so it wont let me down later.
Anybody have any suggestions of what could cause this? Maybe relays going bad? Loose connection somewhere, but where could a loose connection cause this kind of symptom?
Thanks

[Dragcity]

Have you done any work on the car since it last worked? Has it been sitting a while?

Out of Air - Fuel - Spark, my guess is air. Is the MAF plugged in? Starts, so you have spark. You smell fuel, so you have fuel, unless you have a leak????

[Windsor58]

No recent work, mine or otherwise (I can't work on it myself anymore due to health issues). Anyway, it had sat less than a week and ran fine last time I drove it.
MAF is a good idea. I'll check that. Thanks.
Other air doesn't seem likely since it fires on all 8 and revs smoothly and normally until it dies. I would expect some roughness on start if the A/F ratio were out of whackk from a vacuum leak or other air i take issue.
No indication of a fuel leak either. I don't smell fuel or see any drips until I pump the throttle trying to keep it running when it dies. When I do that a few times in a row is when I get a mild smell of fuel.
Thanks. I'll check what I am able to when I get it back.

[Turbov6Bryan]

I would say crank sensor, just because you have to pull the ac compressor to do it
It's not the cam sensor, your getting fuel

Check for spark next time your car doesn't start

[Fastbob]

Quick and easy test...When it has the problem unplug the MAF and see if it will start and run. If it does you have found the problem.

[Turbov6Bryan]

Quick and easy test...When it has the problem unplug the MAF and see if it will start and run. If it does you have found the problem.

^^^^---- that works too. If it's running tap the MAF with the heavy side of the screw driver. Not super hard. If the car stumbled, the diode is loose or faulty. Or are these mafs frequency mafs? Idk?

[Windsor58]

Thanks. Good suggestions. I got the car back and its running and starting fine. Just checked for DTCs and it had a P1235, FPDM out of range, so I'm guessing its the FPDM or a relay. Dont know if it has relays for that or not. I'm running a Aeromotive stealth fuel pump but I think the FPDM is the stock unit.
I cant get under the car any more so I'll need to take it back to the guys who installed the pump for me a couple years ago.

[Jrod0208]

The regulator for the alternator! That's what my car was doing too, it took me acouple mechanics to figure that one out


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[Windsor58]

The regulator for the alternator! That's what my car was doing too, it took me acouple mechanics to figure that one out


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What other symptoms did you have?

[FordNut]

Maybe the IAC valve.

[Jrod0208]

It would turn off when idling and or in low rpms!!! The worst time in my life!!


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[FordNut]

Thanks. Good suggestions. I got the car back and its running and starting fine. Just checked for DTCs and it had a P1235, FPDM out of range, so I'm guessing its the FPDM or a relay. Dont know if it has relays for that or not. I'm running a Aeromotive stealth fuel pump but I think the FPDM is the stock unit.
I cant get under the car any more so I'll need to take it back to the guys who installed the pump for me a couple years ago.

Just noticed this.
Could be the fuel hose connected to pump (inside tank) leaking

[Windsor58]

FasttBob, good call. The dtc never came back so I think that was a fluke. But the starting problem did re-occur. I tapped and wiggled all the relays with no affect. Then tapped the MAF and it started up fine. I pulled the connector off and cleaned it and put it back in. Now to see if the problem comes back, indicating a bad sensor or if it stays good. BTW, the car has a Ford GT blow through MAF set up (behind the aftercooler).
Thanks guys. The help is greatly appreciated.

[tbone]

Aeromotive Stealth pump = Upgraded FPDM and 30 Amp relay.

[Windsor58]

Aeromotive Stealth pump = Upgraded FPDM and 30 Amp relay.
Thanks. That makes a lot more sense.

[fastblackmerc]

Aeromotive Stealth pump = Upgraded FPDM and 30 Amp relay.

How / where did you wire in the relay?

[Windsor58]

How / where did you wire in the relay?
If your question was for me, I didn't do it. A shop in Colorado Springs switched the dual Fkrd GT pumps out for a single Aeromotive pump and did all the necessary changes to the wiring at that time. I don't know what all those changes entailed.

[Jtrip]

Need suggestions. My car will start, go through the short rev up when it fires off. Then as the rpm drops back down and should go to idle, it dies. It dies at the same point every time. Its like the rev after it catches is open loop and after 3 seconds or so, it drops to a closed loop idle, but thats when it dies every time. Checked everything I could (limited) and finally had it towed to a shop I use. The first time they tried it, it was working normally. It didnt die for them at all! (of course-take it in and it aint broke any more... arghhh).
Any suggestions what could be doing this? I dont believe its fuel. Has 60 psi just before trying to start it. The pressure drops but not abnormally when the starter is engaged. And when I tried pumping the gas pedal to keep it from dying a few times and I could smell fuel so I think the fuel is being pumped through but not ignited when it dies. So, I think its electrical but I dont know what would cut the ignition right after it reved up on start.
Yes, its working ok now (at the shop) but when will it fail again? I'd like to figure it out and fix it so it wont let me down later.
Anybody have any suggestions of what could cause this? Maybe relays going bad? Loose connection somewhere, but where could a loose connection cause this kind of symptom?
Thanks

Mine did the same thing this morning. Tried to start three times. Gave it gas third time and shot out fuel smelling exhaust.

You ever get this figured out??

[Turbov6Bryan]

Mine did the same thing this morning. Tried to start three times. Gave it gas third time and shot out fuel smelling exhaust.

You ever get this figured out??

Possible it was flooded. Turn key off, floor gas pedal and normally that shut off the injectors, crank until it almost fires up and let off the gas pedal

Mine did it 2 days ago

[Jtrip]

Possible it was flooded. Turn key off, floor gas pedal and normally that shut off the injectors, crank until it almost fires up and let off the gas pedal

Mine did it 2 days agoTried it again this morning. Did the same thing twice, started then died. Floored the gas pedal, turned it over for a while, then tried to start again. Started right up that time. Thanks for the help.

I forgot to mention earlier that she stalled on me coming out of a parking lot. Just bumped the throttle to get out in the road and coasted to the light. Stalled but started right up. Also has a problem starting on first turn after being run for a while.

Any guesses?

[95chickn]

Ive been going through same thing....Ive been replacing everything.....Frustrated over a year and half since i drove my beauty

[tbone]

How / where did you wire in the relay?

Put the 30 amp relay in place of the stock 20 amp relay.