4.9 misfire
Thread Starter
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Junior User
Joined: Jan 2007
Posts: 99
Likes: 0
From: Southern Md.
4.9 misfire
I have 94 e-150 4.9 auto, traveling at highway speed it has an occasional miss or stumble, it is noticeable at idle, idles smooth then just hesitates and goes back smooth. Has new plugs, distributor, wires,.
Thanks,
Thanks,
Lead Driver
Joined: Feb 2003
Posts: 8,140
Likes: 4
From: Oak Harbor, OH
It sounds like the TPS or IAC may be going bad. Pull the codes and see what the computer is telling you. Then go from there. Also just because the CEL isn't on does not mean there aren't codes stored.
Thread Starter
|
Junior User
Joined: Jan 2007
Posts: 99
Likes: 0
From: Southern Md.
Thanks! I might try one , Did your 4.9 stumble and hesitate going down the road and also at idle. It does run better at idle and the miss stops when I pull the plug out of the MAP sensor, would this indicate a bad sensor?
Lead Driver
Joined: Feb 2003
Posts: 8,140
Likes: 4
From: Oak Harbor, OH
Possibly, usually when the MAP sensor goes bad it won't run at all. Mine had a 351w in it, and yes it did the same thing. We put a new fuel pump in it, and a complete tune up including filters and it went away. If the TPS voltage is dropping it will cause was feels like a miss too.
