96 model has very odd rough idle

today i have just bought a 96 explorer with a 4.0 v6 that has an odd ilde that i havent been able to find and read about in any other thread. when i start it it revs to about 1500 down to allmost stalling about once per second. after i put it in drive and give it gas for about 10 seconds it stops, then while idling for about 2 minutes it starts doing it again. after about 15-20 seconds it stops by itseslf. it hasnt stalled yet but its just irritating. I dont really have the money to replace much or the knowlege. if there is any idea of my problem please let me know. also the temp meter stays at about 3/4 the way up. it is full of antifreeze and the fan constantly runs. it may not be a big issue but i just dont want it to over heat.

Matt

Welcome to the forum!

So even when you first start the Explorer, the temp gauge is 3/4 of the way up? If so, it sounds like you need to check and/or replace the coolant temperature sensor and the coolant temperature sender. Is the fan on your '96 belt driven, or electric? I figured it was belt driven, in which case it would appear to run all the time the engine is running.

If your coolant temp sensor is not reading accurately, it will cause your PCM to modify the air/fuel ratio in ways that could cause erratic idle, not to mention poor fuel economy.

Also check your air filter to make sure it is not nearly plugged. If you are comfortable dinking with the Mass Air Flow sensor, pick up a can of CRC Mass Air Flow Sensor cleaner and follow the instructions to clean the MAF sensor. If you happen to have an oiled air filter (such as a K&N), cleaning the MAF would be high on my list of items to check.

Also, make sure all the air intake tubing is secure and consider checking the back side of the throttle plate for carbon build up as well as cleaning the Idle Air Control passages.

-Rod