Hey folks, my g/fs 99 Explorer Sport with the 4.0 SOHC is having so issues with starting/running/stalling. The other day after she got off of work, the truck would not stay running, it would turn over get up to idle, and then start stumbling and died. This process continued for a few tries, until she decided to give it gas once it turned over. At this point it would stay running but only until she released the gas, once she got off the pedal the truck would die out again.

Upon getting the truck home, we ran a scan tool on it, which revealed no codes, either active or pending in the ECM. At this point the truck was starting up fine. We were all a bit confused to say the least. I suggested perhaps it was in need of a tune up. But decided it would be best to do it step by step, so I sent her out to buy only spark plugs. We properly gapped the plugs and installed them. The truck ran better, and got a bit better gas mileage. We thought this had solved the problem, however 2 days later the problem returned.

This time the truck didn't start at all. Being that I was at work at the time, i came home on my break, checked it out, it wouldn't start, so I told my g/f I would look at it when I got back. Then when I got back, the truck started right up, no problems.

At this point I'm thinking perhaps it's getting intermittant fuel delivery. I decided to change the fuel filter, last night. This morning the truck started fine, but about 2 miles down the road it began to stumble, but didn't stall. The problem appears to still be around, any ideas? I don't want to play guesswork. Thanks!

-Anthony

 

Put an IAC valve in it, will probably fix the issue.

 

What was/is the weather condition when the problem occurs? Damp? Cold? Being a 99, it could be in need new plug wires and you're getting spark leakage around the plug boots. Use a dab of dielectrical grease on both ends when installing the plug wires.

 

Hello again folks, I just got off the horn with my g/f and she tells me again the problem occurred, without keeping the foot on the gas it simply will not stay running. Keep in mind that this problem is intermittant. In case you're wondering the weather here today is rainy, and humid.The weatherhas been like this on an off of the last few weeks. A ford tech I just spoke to also advised that it might just be the "Idle Air Motor"? I'm guessing he meant the IAC Valve? Also where might this be located on the truck, if possible I'll get at it tonight. Thanks!

-Anthony

 

replace the cheapest things 1st


IAC

but check your starter connections or have it checked it could have a loose sileniod. or your a;ternator is dying or your fuel pump is going bad etccccc.

 

IAC valve is located under the splash shield on very top of engine, 4 7mm head screws hold it down, take shield off and is only silver colored item under there, on very top of intake.