X won't run/fuel pump out?

[swep1]

I have a '96 4.0 cylinder V6 Eddie Bauer edition Explorer. The last couple days, it's been a bit slow to crank and this morning it would turn over but as soon as I released the key it would die. I can keep it running as long as my foot is on the accelerator, leading me to believe that it's the fuel pump dying. Going to try my best to inch it along out to the Ford dealer tonight after the traffic dies down and leave it out there for them to take a look at first thing in the morning, but thought I would check with the Explorer experts here first and see if anyone has dealt with a similar issue. Thanks in advance!

 

[Alec]

How does it run when driving?

Sounds like a faulty IAC or maybe FPR to me, not the fuel pump.

 

[swep1]

That's pretty much the problem...if I take my foot off the accelerator, the car dies or putters like it will die any second. So far, I haven't managed to get it out of the drive way without it dying on me.

 

[Alec]

Try unplugging the IAC and see if the problem goes away.

My reasoning for thinking it's not the fuel pump is that the truck runs with the accelerator. If the pump can supply fuel with the accelerator, then it shouldn't have a problem at idle.

Could also be a clogged fuel filter.

 

[swep1]

I've never had a problem like this before, so I started with the archives on this site...there are at least a couple of old posts that seem to suggest that depressing the accelerator forces the fuel pump to push fuel into the engine, which is partially why I thought it may be fuel pump related, but that's why I thought I'd feel you guys out for other suggestions...

 

[swep1]

I managed to get it out to the local Ford dealer this evening. Same thing, when cold and first starting up, I had to hold down the accelerator to get it started and it puttered along for the first couple minutes, once I got moving, the car seemed to be fine and once I got to Ford, and killed it and restarted it a couple of times, it started smoothly. I don't know if that helps you guys diagnose what's going on, but I appreciate all the help you all can give me.

 

[Alec]

Yup, not the fuel pump or fuel pump relay.

Clogged fuel filter, sticking FPR, or sticking IAC are my top 3 thoughts.

 

[JDraper]

I'd also say IAC is a likely culprit. That or a vacuum leak. The not idling but running ok definitely would point me to the IAC. If it were the fuel filter, you would probably have trouble at speed too.

 

[bipolarbob]

Change the feul filter before you cook the pump

 

[swep1]

Well...the explorer has been with my local Ford dealer's driveability mechanic for the last 2 days now and they can't find a single problem with it. They've connected it to diagnostic computers, to oscilloscopes to check the idle, they've connected recorders to see if it was an intermitant sensor causing the problem and even kept it today to see if the change in temperature (it was cold on Sunday when I had the problem and the temperature here dropped again overnight) might have played a part in it and their overwhelming answer was "come get it, we can't find anything wrong."

The mechanic that drove it did say that he thinks there might be a minor suspension issue on the front driver side (he claims hearing a small knock that might suggest a shock going bad) and a small click coming from the engine that he claims might be bearings in the alternator going out, but otherwise he says it's in perfect running condition for a '96 with nearly 100,000 miles on it with no major problems that are gonna leave me stranded or cost me a small fortune.

So, tomorrow morning, Í'll go pick it up and drive it until it acts up again, but I fear that this issue is far from over.

The only other possible suggestion they could offer, and I'll run it by the experts here, was that there is the possibility that the torque arm was locking up due to a small pressure leak coming from the transmission, but that seems rather unlikely and that was their bottom line as well. Or, that I might have had a small fuel line blockage that cleared itself once I got it running, or that I had a bad tank of gas...

Thanks again for all the suggestions, when I mentioned them to the mechanic and service dept. people, they thought you all were most likely right on target but they never could make the problem re-occur, so now we'll wait until it happens again and hope that they're more successful in tracking down the problem.

Any other ideas???

 

[88vert]

Could be bad gas I have had that same problem and could not figure it out,then all of a sudden it fixes itself