Surging

[Jim P]

Every once in awhile my truck will surge if you lug it down to where it almost stalls. Have any of you guys had this problem?

One day I was pulling into my mother-in-laws driveway and I was just idling along in second gear because she was mowing the grass right close to the driveway. As I started up a very small grade, the engine started to work a little and all of a sudden the engine surged and gravel started flying of the back tires so I clutched it and everything was back to normal. Just the other day I was driving through a guys yard with my trailer on the back and again I was just idling along so I didn't tear up his grass. I just started up another little grade and the engine started to work a little and All of a sudden the engine surged and I gave the guy a nice yard job before I clutched it and it went back to normal again.

I can also get it to do it if I move the gas pedal up and down three or four times real fast. It seams like the computer can't react fast enough and gets confused. The engine will keep surging for two or three seconds after you quit moving the gas pedal.

Is this normal for these drive by wire trucks?

[charliepeterson]

"Is this normal" NO.

The Injection Pump is failing. This is one way for it to fail with out setting any engine codes. Last winter I had one do this at my shop. It's not as common as the other ways to fail.

You're still in the game for time on warranty, how about mileage?

[pannhead]

may want to take a look at the APP..throttle is drive-by-wire..just an idea,could be alot of things like most stuff on these trucks...good luck

[ChevyDooley]

Mine has similer problems but I know its the throttle position sensor thingie for a fact because it never does it with the cruise control on Ive tested this for weeks now. Try that to see.

[Jim P]

The pump was replaced about 6,000 miles ago, just before I bought it. I only have 86,000 miles so I know it would be under warrenty. I have a code pop up know and then and I think it is a 99, which is something about accelerator pedal position

[pannhead]

yup, thats the APP...best to fully test it,they are mega-bucks and dealer only

[Jim P]

I have read that you can take the accelerator position sensor apart and clean it but how do you go about doing that?

I'm sure that it could be dirty because the truck belonged to a company that did blasting in strip mines. When I bought the truck it had about an inch of dried mud on the floor and about 2 inches covering every square inch of the under side if the truck.

[ktobin]

I read somewhere about drilling a couple of small holes in the housing and spraying some contact cleaner in. It was supposed to clear the problem.
Be careful with the drill. Just the housing and not the Guts. Let us know if it clears 99