Fuel pressure loss when hot?

Pantera1

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When the car is at operating temp (15 minutes on the highway) and just cruising the car will randomly stop accelerating. If I tap the gas pedal itll sputter and go back to the power loss. If I turn the key and bump the starter itll drive normal again for a minute before losing power again. I've gotten it to do it at idle a few times and my fuel pressure gauge on my regulator reads 0 and will idle bad before eventually killing itself. My tuner says it looks like the ecu just freaks out right before it happens. Car has gen 4 whipple, also did id1050x, aem 320 pumps and new lines at the same time.
Does anyone have any leads on where to look?

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wkornf

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for what it's worth I had similar issue and it was the pump. however it's just as likely anything electrical upstream. do some diagnosis



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01yellercobra

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Sounds like a problem I had with my AEM pumps. But my issue was at WOT. At part throttle it was fine. I could watch the fuel pressure drop when I punched it. Turned out one of the pumps went bad. I thought I could use them in a returnless set up, but that wasn't the case.
 

P49Y-CY

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i think I have the same problem, the car only shuts down after it runs for about a half hour or so.
 

P49Y-CY

fomocomofo
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That's exactly what's going on

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in my case i have another identical car that i have been able to swap parts with and so far i have tried just about everything except the fuel pumps... injectors, cop's, maf, tb, fpdm, frps, etc.

i am now in the process of dropping the fuel tank to check it out. my car has 126k and still has the stock eaton.

(i understand that the better, more professional way to diagnose this kind of problem would be to datalog and scan different parameters, but i am not too good with computers and swapping these parts has not cost me any money)

edit: it is not my pumps, and since your pumps are new op i doubt that they will be the problem in your case either. did your tuner say anything else other than your ecu "freaks out"? it is a very strange issue - in my case the car runs fine for about a half hour each time before stalling.
 
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Pantera1

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in my case i have another identical car that i have been able to swap parts with and so far i have tried just about everything except the fuel pumps... injectors, cop's, maf, tb, fpdm, frps, etc.

i am now in the process of dropping the fuel tank to check it out. my car has 126k and still has the stock eaton.

(i understand that the better, more professional way to diagnose this kind of problem would be to datalog and scan different parameters, but i am not too good with computers and swapping these parts has not cost me any money)

edit: it is not my pumps, and since your pumps are new op i doubt that they will be the problem in your case either. did your tuner say anything else other than your ecu "freaks out"? it is a very strange issue - in my case the car runs fine for about a half hour each time before stalling.
That all he said to me. My car runs fine for 20-30 minutes then dies randomly

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MG0h3

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Could be vapor lock.

Go pull the cap after it happens and see if you get a big woosh of air.

If you could log you could monitor FPDC when this is happening.

ECM failure is incredibly rare.


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Pantera1

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Could be vapor lock.

Go pull the cap after it happens and see if you get a big woosh of air.

If you could log you could monitor FPDC when this is happening.

ECM failure is incredibly rare.


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I had read something that said maybe having the regulator exposed in the engine bay may introduce too much heat to the fuel system, maybe that's my problem

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MG0h3

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I had read something that said maybe having the regulator exposed in the engine bay may introduce too much heat to the fuel system, maybe that's my problem

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Doubtful. All foxes had it. Plenty of Cobra guys run that way. Possible that the pumps are going out and the heat adds load and they don’t like it.


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MG0h3

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Did you delete the Evap system by any chance?


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Wings65288

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Yeah I've heard flow through is better for preventing vapor lock. Thats what im going with. Just a thought.
 

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