Ford F150 issues

[ToadHill]

I have a Ford F150 4.2L with auto trans. Recently it has developed a problem I can't seem to figure out. When I get up to 55mph or above and cruse along I suddenly get what feels like a high speed miss, or momentary hesitation. If I kick it into passing gear, the miss goes away but will come back when I slow back down. I never have the problem at speeds around town.

I've changed the plugs within the last 300 miles. The fuel filter has only a couple thousand miles on it. The miss doesn't seem to cause the check engine light to come on.

Anyone have any suggestions?

 

[Tig]

If you have an electric locking torque converter, it may be acting up. Locking and unlocking, which isn't really abnormal in the Chevys I have owned. It will cause the truck to lurch a bit and you will see engine speed go up and down a hundred RPMs or so. I used to notice it on my Chevys at 50 MPH. So I would drive 55. When my converter locked up and would not unlock, I found the wire that went to the bell housing and pulled it off. Never had another problem. You may want to disconnect it as a test.

 

[tallyho8]

Even though your check engine light does not come on, I would put a code reader on it and see if any codes show up.

 

[caver]

I had a problem like that recently and it turned out to be plug wires.

 

[Soundguy]

Check your throttle position sensor. I had my dodge ram 1500 doing exactly that.. went to the dealer they did a trans service.. didn't fix it. Later on I was setting at a stop light and the engine surged in rpm BIG time. had i not had my foot ont he brake good, the truck would have lurched. I took it IMMEDIATLY to the dealer again.. who then repalced the TPS... that fixed it.. never has done it again.

soundguy