Funky problem (to me)

[AKJDL]

Brand new to the forum and I'm lost...

I've a '91 2dr V6 Explorer 'Sport' 4X4 - a beater with a heater... Normal driving, 15-20 miles, no problems noted. Finally took it to town (50 miles) and got an intermittent check engine light. At the first stop light, stuck it in N to listen to engine and it idled at 3K rpm. Back in D and seemed to run fine. Return trip ran normally for 35 miles, then int. check engine light - high rpm again in P or N and I noticed continual shifting/down shifting over last 15 miles. I bet it shifted 50 times with rpm change between 1700 - 2300 at 60mph on a flat surface. Finally, and for the first time, when cold it seems to be unable to catch the idle when shifting into gear - rpm drops and it dies. Warms up it's fine. Anybody have any helpful hints, I'd be obliged... Thanks!

 

[natenkiki2004]

That is odd and I recall another member having a similar issue. I believe it was mentioned in the other thread too but it might be your idle air control valve. If it's frozen or not working right, it will cause chaos.

It'd be best to pull the trouble codes and see what the computer has to say. Usually when it goes on and off, there's something barely functioning that fails and then the computer corrects for it. Poor connections would be a good example of that, intermittency. Anyone here will say to pull the codes, it's quick, free and tells both you and us more about the problem you're having.

 

[madbutcher]

might be the TPS.. That was the problem with my old 91 Explorer

 

[swshawaii]

How To: Pull Trouble Codes on a 1st Gen Explorer (paperclip method)
http://www.explorerforum.com/forums/showthread.php?t=255962

 

[AKJDL]

I'm told the codes aren't retrievable on that old a model bc the check engine light doesn't remaom illuminated... Thanks for the reply, I'll replace that valve first thing... Thanks again

 

[natenkiki2004]

You don't have to replace the valve, though they are cheap. Take it off & clean it, worth a shot.

With the paperclip method posted above, the codes are output via the check engine light with flashes. Works on a LOT of Fords and many other pre-OBD-II vehicles (just different methods). A reader/test light/multimeter will do the same exact thing that a paperclip will, it just uses something else to display the info.