engine hesitation..

[Kingkong]

well about two weeks ago my check engine light came on and i could not acclerate hard at all, so i changed the spark plugs and wires and cleaned the maf. while i was taking out the spark plugs i noticed one of my spark plugs had broke into two pieces, that's what was probably causing the problem. but after i changed all that, the check engine light went away and the power was back and everything. but now if the engine is under stress, like if it was in second gear at 1500 rpm and i was going to acclerate 1/2 or more on the pedal, it would hesitate while speeding up until it hits about 2500rpm. by the way it's a manual transmission. it never use to do that until the check engine light came on and i changed all those. i've already check for tightness in the spark plug wires and they're on tight. could a wrong gap cause this? because i gapped them at .045 because i saw that in a search i did. and the motor is the 4.0 ohv. well any help would be greatly appreciated.

 

[Kingkong]

anybody??

 

[Kingkong]

oh and when the engine is cold it doesn't seem to hesitate. but after a few minutes of driving then it'll start doing it. somebody must of had this problem before or am i the first....? well any help would be appreciated..

 

[sonik]

There are a ton of sensors, valves, and filters that can be checked. Since the problem is temp-related I would check the sensors that relate to temperature. Have you tried searching the archives? Try this thread: http://www.explorerforum.com/forums/showthread.php?s=&threadid=78885&highlight=engine+hesitation

.045 might be too small. The "book" says .052-.054 and I see suggestions on here down to .048

 

[TPLYNCH]

Did you reset the computer after you did all the work?

 

[AlmostaBronco]

How many miles on it? More than 75K i suggest you sell it and get yourself a Japanese car