Low Idle when cold

[rseeley]

I have recently purchased a '91 Explorer with 238,000 miles. The motor runs very strong. However when I first start it I have to hold the gas down to keep it running until it is warm. Even when warm it seems to idle a bit low (less than 1000 rpm). I think it might be the idle cellenoid or the throttle position sensor. However these are non-refundable electronics, so my guesswork could prove to be expensive. I thought this might be a common problem and would appreciate any assistance.
Thanks....

 

[TPLYNCH]

Welcome to the board! Hopefully we can answer all your questions. First guess would be the Idle Air Control valve. You can try cleaning it. Also, you can clean the Throttle body too. Replacing the IAC is not a big deal. Search for it and you find lots of threads. The following site has lots of great info, especially for the older models. Bookmark it!
Dead Link Removed

Good luck!

 

[Jag]

It could also be a defective air temp. sensor or a water temp. sensor, either one of which could be "fooling" the computer into thinking that the engine was warmed up.