Why is my truck kicking at 35 and 45 mph?
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Joined: Jul 2011
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Why is my truck kicking at 35 and 45 mph?
I have a 2001 Ford F-150 with 115K miles. In the last year it has starting kicking and bumping really bad at 35 and 45 mph,, I tried replacing the plugs but that didn't work,, it rode smoothly for a few days after that then went back to kicking and bumping. I was told maybe try to replace to coils but I would bet you all know what you all are talking about so I was wondering what you all thought I should do. I haven't really replaced anything major since I bought the truck brand new in 2001,, thanks!
Lead Driver
Joined: Sep 2006
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Pay close attention.
Yes indeed you have one or more coils with low output.
The reason the plugs cleared it for awhile is they covered up the faulty marginal coil until they aged enough to require more voltage to fire the very lean A/F during cruise conditions and light throttle application, then you back to the missfire conditon cycling all over again.
Amazing how fast plugs will deteriorate and be detected under these conditions.
Leave the plugs in. Changing them again won't buy you anything more.
The reason you got no CEL, or code is the coil fault of low output is not a
'hard' fault because the drivability issue come and goes with the driving condition and the PCM cancels the record of it temporary memory.
The next trick is finding which cylinder it is.
Either cycle a new coil through each cylinder and test run each change or have a dealer stress test all of them.
Good luck.
Yes indeed you have one or more coils with low output.
The reason the plugs cleared it for awhile is they covered up the faulty marginal coil until they aged enough to require more voltage to fire the very lean A/F during cruise conditions and light throttle application, then you back to the missfire conditon cycling all over again.
Amazing how fast plugs will deteriorate and be detected under these conditions.
Leave the plugs in. Changing them again won't buy you anything more.
The reason you got no CEL, or code is the coil fault of low output is not a
'hard' fault because the drivability issue come and goes with the driving condition and the PCM cancels the record of it temporary memory.
The next trick is finding which cylinder it is.
Either cycle a new coil through each cylinder and test run each change or have a dealer stress test all of them.
Good luck.
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