Strange problem

[Gregg1LE]

My '00 XLT is experiencing a surging / slipping on the highway after it is traveling for a while.....it does not do it any other time. Sort of a slipping /loss of power at highway speeds.....I can't figure if it is the tranny,
bad fuel or filter or what.

The only variables are that the battery has needed a jump twice a few months back and my wife just filled it up with gas.

No check engine lights.

Any ideas? Thanks.
Gregg

 

[AUTOTECH SON :)]

Well its a bit harder when im not presint but I would have somethings to say that may help you may have a vacume leek which is sentralized on the throtol body. Also u said that u have had a jump twice please go in to detail on that as u may have damaged ur computer.

 

[Gregg1LE]

Well its a bit harder when im not presint but I would have somethings to say that may help you may have a vacume leek which is sentralized on the throtol body. Also u said that u have had a jump twice please go in to detail on that as u may have damaged ur computer.

I don't think it is a vacuum leak, as the truck drives good until it has been on the highway a while. It is fine when it is cool.

 

[AUTOTECH SON :)]

give me detail how did u jump ur x and also when u say sliping do u mean to say that the trany is hunting for gears or that ur engins rpm is pulsing holding reving or droping. o 1 more thing i suffer from a sleep disorder si forgive incoharentcys tiypos etc.

 

[Gregg1LE]

give me detail how did u jump ur x and also when u say sliping do u mean to say that the trany is hunting for gears or that ur engins rpm is pulsing holding reving or droping. o 1 more thing i suffer from a sleep disorder si forgive incoharentcys tiypos etc.

I don't know how it was jumped. Both times my wife had it done.

The tranny runs fine through the gears and these incidents only happen once the truck is warmed up and hot. But nothing on the guages indicates a problem and again no codes.

To me it feels more like a RPM drop.

Don't worry about the typos, I have no problems reading and understanding.

 

[AUTOTECH SON :)]

ok when the rpm drops dose it go back to normal then drops? Like a teter toter? O and when u start ur x have u ever hurd a backfire from under the hood not loud but muffild or have u seem a small amount of smoke ome from under the hood?

 

[TPLYNCH]

Does it happen/correspond with when the a/c compressor is running? If you have the control set to Panel, does it do it?

 

[Runnin'OnEmpty]

Tom suspects it's 'surging' because of the A/C clutch cycling, and so do I. Any other problem that would cause those symptoms would surely trigger a MIL. Maybe it only needs some R134a added.....?

 

[AUTOTECH SON :)]

hmm well porcess of ilimination. a friend of min had the same isue but it was a vacume leek. I wish i could see and hear it in person as i have better tools to diagnose it.