Okay ford Gurus ,

My 5.4 is missing again , its starting to get to me , especcially when my friends are riding with me and I am telling them how good ford products are . Miss , miss , miss , that all this motor seems to do . Okay , I will stop whining , Last year I washed the motor and it missed for three days , okay , my fault here , it stopped after 3 days and all was well ,btw , it was a dead miss , at idle , at speed , everywhere . Six months later , after a bad week of rain , does the same thing , but goes away after a couple of days , cool!! Meanwhile , I have replaced all my plugs , inspected my coils , changed the pcv , etc. This work was all done about three months ago while the motor was runnin good and stayed that way until 5 days ago , the miss started again , but this time it is a little diffrent . The last two times it was a dead miss , it set my check engine light off almost right away and then went off after miss disappeared . This time , it is not a dead miss , its like a sputter , . Like the other people on this board , its at about 1500- 2000 rpm . If youare doing 40 and you accelerate faster but do not get the trans to drop down to third , it misses like hell , but if you do get it to jump down , it does not seem to miss . Also it does not miss every time I do this , sometimes it runs perfect for a stretch of road and then starts up again . I also have no check engine light either , so I don't even know which plug it is . It will also missfire at idle sometimes , but genrally it idles perfect . I know this is a common prblem , what steps should I take ??? The plugs and coils are such a pain that I hate to dive in with out knowing which one it is . Any help would be appreciated . I haven't cleaned any of the sensors yet , It seems to run okay , idles almost perfect and runs out when its not stumbling and missing . Would the tps or the Iac have anything to do with it , or what about a wire harness plug coming from the pcm ?? Also , can you buy the spark plug boots for the COP seperately ?? I noticed a few of mine where cracked a little near the end , which could be the source of the problem . Also , I have heard very little on this board of the effects bad fuel , it happened almost right after I filled up . Any Suggestions for a fast fix ???

 

If you can find out what the ohm reading is supposed to be on the coils, you may be able to check them that way. One could be weak.
Jimmy

 

if you can scan the engine it will tell wich cyl is missing and you probably will have to replace the coil make sure you check the plug I carry a spare coil with me on long trips just in case one goes bad in the middle of montana some times if you can get to coil wiring or injector wireing you can unhook each one while the truck is missing and the one that doesnt make the motor run worse is the culpret from past experience 3 and 4 are most common

 

Go to Autozone and they'll get a read out on your error codes, it will narrow down the possibilities real quick. Just to much going on with the electronics in these engines to make an easy diagnosis.

I have a 4.6 in a Merc and was on the CROWNVIC.NET site to ask questions about my 4.6 blowing white smoke. I had suggestions on everything from blown head gaskets to leaking valve seals to it just being cold. Suggestions to fix ranged from buying a new engine to ignoring it - maybe it will go away. Pulled into one of the few Ford service stations I trust, manager unhooked the battery for a minute, turned then key to make sure all the juice drained from the system then hooked it up again. Computer was screwing up the fuel air mixture and it reset after unhooking the battery. Car was back to running like it should - NO CHARGE. He said you see it once in a while, engine is nine years old and this is the first time it had done it, probably never see it again.

 

What your discribing could not even be a miss at all. If the check engine light flashes a "miss" code then your right. If the code has something to do with running to rich or too lean, then I would have ford put it on the wds diag machine, about $100. I had the same symptoms with my 1999 f150 5.4l with 130k miles. I replaced spark plugs, Iac, cleaned egr, checked for vacum leaks, did fuel filter, cleaned and almost bought a new maf, in the end the problem turned out to be electrical, I had a lead coming from the TPS or MAF that was grounding out on the chassy. Fix cost me about $200 with wds scan included. Now my truck runs better than ever.