I've got a new problem on my 2001 4.0 guys.. Sometimes when I turn my truck will either slow the idle to about 500rpm and get a little harder to turn or die mid-turn. It only happens on pavement but sometimes it does slow down in RPMs when turning to enter my gravel driveway. Today the engine died for the first time while in mid-turn on pavement. Completely off the throttle and turning. Just coasting. Dangerous to say the least, but more annoying for me.

I have noticed that since I got the 31" mud tires that it did seem harder on the rack & pinion. Just seemed harder to turn than before.

So does this just sound like a worn out rack and pinion making the truck bog down in RPMs or is it something else that I'm not aware of??

P.S. It's an automatic just so you know.. Also, the power steering pump makes no noise and uses no fluid at all.


GB :)

 

Sounds to me like the IAC (Idle Air Control) isn't doing it's job. It may be gummed up. You can try taking it off and cleaning it or you may have to replace it.

 

Would the IAC only affect the engine RPMs during a load such as turning with no throttle being applied? Because otherwise the engine runs perfectly at all other times..

Also, do you know where I can find a picture of the IAC so I know what I'm looking for?? I'll keep searching on here in hopes of finding one but so far I haven't found any. I've been reading on the subject lately.. EDIT: Found it in my Haynes manual.

EDIT: The Haynes also mentions this: POWER STEERING PRESSURE SWITCH - The pressure switch may close before the load from turning and may cause an idle problem. It goes on and on about the switch and the PCM.

ANYONE ever had Ford work on their powersteering pressure switch or replace it? I searched here already....


GB :)

 

Well, I cleaned the IAC and put it back on after drying. After that I hooked the battery back up and idled the truck in park for 3 mins, then in park with AC on for 3mins, then parking brake on and in drive for 3mins, then the same with the AC on. A member told me to do that to re-learn the idle..

If anything, the idle is now lower than before. Looks to be somewhere around 600-750rpm by the tach. It used to idle at around 900-1000 or so, I think. It still slows the idle when braking around/through corners but hasn't died on me just yet. So we'll see if anything improves or changes.

If I can find the idle re-learn process on here, then I'll try it all over again. Also, if I can find the specs on the IAC then I'd like to check it with an ohmeter.. Resistance through the connector to the case, and through the electrical connector itself.


Any other ideas guys??



GB :)

 

Braking causing it to stall may be an engine vacuum problem or a bad brake booster.


To see if the IAC is functioning, simply remove its electrical connector while the engine is running, see if the idle changes. Change means it's working. Might try with the AC on/off.

 

I'll try that with the IAC but at this point I'd say it's functioning correctly. It wasn't even very dirty at all.

I wasn't really applying the brakes when it died. It was just after releasing the brakes and coasting through the turn. When hitting the brakes it doesn't change the idle. It's only while turning, or turning and hitting the brakes at the same time while the truck is already at a low idle speed.

Thanks again for the help guys. Seems like I'm not getting much action here besides you two.. I appreciate it.


GB :)

 

Well, I was driving around in town today with the A/C OFF and the truck died again at a stop sign. This time I wasn't turning. I've cleaned the IAC and it's spotless so I guess I have to find the resistance values for it and check it with a multimeter.. IF I can find the numbers..

Anything else that I may be overloooking guys? Easy way to search for vacuum leaks that won't make an oily mess?? I thought about turning my handheld propane torch on super low and holding it around the vaccum lines, etc.. The idle would quickly change if it sucked in propane. We do this regularly on classic Honda motorcycles...

Dirty MAP or MAF or whatever it's called, sensor? O2 sensor? I'm at a total loss here guys. :(


GB :)

 

Any ideas anyone???


GB :)

 

Hey i just read your post and i am having the exact same problem. Have you found out what was causing your problem yet? Any help would be greatly appreciated man!

 

if I remember correctly it was a cracked vacuum hose on the upper left side of the intake. a hose with a 90 degree bend in it. I did clean the IAC valve again though, as well as the inside of the upper intake and intake hose, all the way to the mass air flow sensor.

apparently the cracked hose is common on Ford Rangers and explorers

GB

 

Any updates here? I am having the same problem on my 1993 ranger. It will stall when stopping quickly or turning.