hey my cel light came on today after i got done cleaning the iac and removing my throttle body and cleaning that as well. I changed my fuel filter in the process. I was getting high idle and the serching yesterday but since i clean it, the idle has dropped down to normal. now i have developed a very rouch engine. I though it was just carbon and dirt that was falling in to the engine so i red lined her to get all that crap threw..ran fine for a little bit. on the way home the cel light came on and started flashing. i got a #3 cyl missfire code (superchips tuner) and cant figured out what the cause is? any ideas where to start?? before this it never mised just had the high idle help plz fast

 

I think you have a new problem. Your old problem was probably the IAC. You have fixed that at least temporarily.

The new problem is the #3 misfire. The most common reason for a cylinder specific misfire appears to be a coil. I'd at least pull the coil and plug to see if there's a visible reason (like water in the well) before buying another one. But then I probably would buy another and try it. If you can read your own codes, try swapping two coils and see if it followed the coil to another cylinder. If it does, replace it.

 

if you have the 5.4 your miss is most likely caused by the super common heater hose drip. your #4 coil won't be far behind.

look above the #4 coil and you will se a rubber heater hose attached to an aluminum one. if it has a factory climp style clamp replace it with a screw type hose clamp. if it has a screw type on it loosen it and push the rubber hose further onto the aluminum one then tighten the cr@p out of it.

good luck!

 

yes i do have the 5.4 from 2000. I am going to take the coil off see whats up and then check the heater hose, any other ideas???? i didnt buy a motocraft filter, its was some other brand for cheaper that wouldnt make just one cyl missfire tho would it?

 

well i switched my missing #3 coil with my #1 coil...it did have like 2 tiny drops of water which i blew off.... then i put it back together and went for a test drive. I had the neg battery cable off while i switched coils.. now my truck doesnt miss (at least it doesnt yet) im guessing it got wet when i sprayed tb cleaner everywhere...but now i have serching idle again! i cleaned the iac and tb and intake elbow to the mani earlier today it fixed it for a short time now when i get the coil problem fixed its back to the problem i started with!!! any ideas??

 

after disconecting the neg. battery the PCM was reset and has to relearn. the idle should smooth out.

 

oh ok how long does that approx take? i have heard anywhere from 200 miles to only 3 decent distance trips like say 20 min each.

 

http://www.obdii.com/drivecycleford.html

 

hey everyone i just replaced the thermostat and cleaned the tb one more time to make sure..sprayed starting fluid on vaccum lines and gasket areas, no leaks and now it runs fine