missfire #3 cylinder

[80shot ranger]

i have a 99 4.0 and at low rpm's it runs pretty rough. at higher rpm's, 2500 or higher, it seems to run fine. ive done a search on the matter and cant seem to find any that meet my specific issues. ive changed the maf and changed the coil. luckily i have another 4.0 laying around. i finally got a code stating that i have a missfire with the #3 cylinder. im gettin ready to go and get new plugs and wires for it and try that out but with my luck, that isnt gonna cut it. i would appreciate any help you guys can provide.

 

[rangerty]

hey i just went through my truck going crazy over this and that as well. it turns out in my case that it was IAC ( i think thats what its called) it contoles the Idal Air Controle valve. Start with the plugs a wires then i would say check that guy out. It is located in the intake man. on the right hand side/drivers side just pased the throtle boddy. here is a thred that has a pic. http://www.ford-trucks.com/forums/136188-idle-air-control-valve.html

 

[snoopdoggie]

If plugs and wires don't help you need to do a compression check

 

[Randy960]

did you figure this out? because I have a similar problem