2002 Exp sputtering/hesitating/stalling at speed

[mdcc]

It is correct that I am a new member... and this is my first post - hello... but I have read all of the posts I can find on my particular situation and am looking for some additional input.

2002 Explorer XLT, 6 cyl/auto no modifications, owned since new.

I live in the mountains of Colorado and on a trip to Vail (200 miles - mostly uphill) last weekend the truck started mildly sputtering while driving 70-80 mph, up the mountain highways, 90 degree day, with the AC on. All gauges read OK, and no dash/warning lights came on.

I pulled over and the truck stalled. It took about minute of cranking and waiting and the truck came to life again. Idle was a little rough - 700-1200 rpm, but then settled back at 700. Pulled back on the road and continued to feel the mild sputtering/hesitation until the truck died while going through a tunnel at 45ish mph. I was able to pop it into neutral and coast while trying to restart it. It did fire back up and I again continued my drive to Vail.

Couldn't have it looked at in Vail because no stations are open on the weekend. Drove it maybe 5 miles in Vail over the weekend and then started home. Felt the same hesitation all the way home (200 miles - mostly downhill) but the truck never stalled.

My initial thought was the fuel pump/filter/regulator and I've done allot of work on my other vehicles but I need the truck for another trip next weekend and didn't have the time to fully investigate the problem... so I took it to the dealership and $100 later they tell me there is no problem... I advised them the people following me in the tunnel when it stalled would tell them otherwise.

I have read about the MAF and IAC problems - but those don't seem to explain exactly what I experienced. It is not throwing ANY codes. The sputtering/hesitation is faint and seems to occur most under load (ie going up a mountain highway). Plugs, wires, and filter are 30k+ old, so the first order of business is a new filter. Premium gas (91), and just stuck in a bottle of STP fuel injector cleaner on the previous fill up.

Should I pursue cleaning/replacing the MAF and IAC - or is there another suggestion? I have never experienced vapor locking in any vehicle, but a mechanic that I met in Vail said he sees cars do it all the time - especially under load on a hot day.

Thank you for your help.

 

[rumpledoll]

Really sounds like a clogged fuel filter. When a fuel filter gets clogged it only lets through a small amount of liquid. The fuel pump is able to eventually supply enough pressure post filter to power the engine for low power demand but when you try and get more power out of the engine and demand more fuel, the pressure at the injectors quickly drops as the fuel pump can't supply that much fuel through the restricted filter.

Only fix is to change the filter.

 

[mdcc]

Yea... propably should not have let that go for 30k+... I think I will replace tonight as that is a quick 20 minute job and see how plugged it is.

 

[mdcc]

Well... got the fuel filter changed last night and it was more difficult to blow through it than the new one... but not as difficult as it should have been given the hesitation and stumbling I was experiencing. It has not done it again - but of course I dont drive the mountain highways every day.

Unless any other thoughts pop up, I will end my search for now and resume should it happen again...