Reposting from wrong group. New to group, but searching for answers

[tbgrey2007]

2007 Chevy Tahoe developed an intermittent engine/tranny problem. The vehicle cranks and idles fine, but does not seem to respond to the throttle, rpms will not climb and vehicle lurches, like the throttle response is really delayed and limited. Local shop changed the throttle body and it ran fine. I picked it up and did not make it a 1/4 mile before it started again. Took it back and ended up putting in a remanufactured transmission. Vehicle has 230k so I figured that was coming. Picked it up, drove about 10 miles home, no problem. It sat for a day or two. I went to drive it and the same problem started again. Had the vehicle towed back to the shop and it ran fine on a test drive. Mechanic took it home and the next morning the problem started again (at least they see I'm not making it up). I checked the V4-V8 mode while it was misbehaving and it was show in V8 mode, so I don't think it is the AFM acting up. Shop has been looking at it for several days and seems to be stumped. Had a motor mount changed several weeks ago. Wondering if something could have gotten pinched during that process (wiring or a fuel line). Throttle position sensor checks out. I asked them to check the fuel pump and catalytic converter (maybe it is clogged up). No idea where to go from here. Thanks.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me will chime in.

 

[Doubeleive]

2007 Chevy Tahoe developed an intermittent engine/tranny problem. The vehicle cranks and idles fine, but does not seem to respond to the throttle, rpms will not climb and vehicle lurches, like the throttle response is really delayed and limited. Local shop changed the throttle body and it ran fine. I picked it up and did not make it a 1/4 mile before it started again. Took it back and ended up putting in a remanufactured transmission. Vehicle has 230k so I figured that was coming. Picked it up, drove about 10 miles home, no problem. It sat for a day or two. I went to drive it and the same problem started again. Had the vehicle towed back to the shop and it ran fine on a test drive. Mechanic took it home and the next morning the problem started again (at least they see I'm not making it up). I checked the V4-V8 mode while it was misbehaving and it was show in V8 mode, so I don't think it is the AFM acting up. Shop has been looking at it for several days and seems to be stumped. Had a motor mount changed several weeks ago. Wondering if something could have gotten pinched during that process (wiring or a fuel line). Throttle position sensor checks out. I asked them to check the fuel pump and catalytic converter (maybe it is clogged up). No idea where to go from here. Thanks.

the MAF can be the cause of this exact problem, just something to have them look at, could be a lot of things though could be wiring if it makes a little ways just enough for the wire or module to heat up and loose contact or create resistance. battery cables should be checked, mega fuse, grounds.

 

[tbgrey2007]

Checked in with the shop today. They put in a second transmission thinking they got a bad one, still same problem. Mechanic said when giving it throttle, the computer shows it as being 100%, but the actual throttle input is fluctuating up and down and usually no more than 10%. Computer doesn't show why it is restricting the throttle. They double checked the throttle bottle and position sensor and downloaded the updated software from GM. They checked the fuel pump and for any vacuum or sensor connector wires issues. Not AFM related. I guess the only positive is that the condition seems to be more consistent, rather than intermittent. A mystery wrapped in an enigma. How can I be so lucky? Any other ideas???

 

[Geotrash]

Checked in with the shop today. They put in a second transmission thinking they got a bad one, still same problem. Mechanic said when giving it throttle, the computer shows it as being 100%, but the actual throttle input is fluctuating up and down and usually no more than 10%. Computer doesn't show why it is restricting the throttle. They double checked the throttle bottle and position sensor and downloaded the updated software from GM. They checked the fuel pump and for any vacuum or sensor connector wires issues. Not AFM related. I guess the only positive is that the condition seems to be more consistent, rather than intermittent. A mystery wrapped in an enigma. How can I be so lucky? Any other ideas???

If the throttle input is fluctuating, I would suspect the accelerator pedal.

 

[tbgrey2007]

If the throttle input is fluctuating, I would suspect the accelerator pedal.

Is that a sensor if some sort?

 

[Geotrash]

Is that a sensor if some sort?

More Information for GM GENUINE 25832864

 

[OR VietVet]

Thought I was gonna be a hero for a second, but @Geotrash beat me to it. I would bet, this part is the problem. Called a throttle pedal pressure sensor. Part of the "drive by wire" system.

 

[tbgrey2007]

Thought I was gonna be a hero for a second, but @Geotrash beat me to it. I would bet, this part is the problem. Called a throttle pedal pressure sensor. Part of the "drive by wire" system.

I called the shop and asked them to check it or if they already have. They surely have to be running out of things to check by now. Maybe the it needs a new ECM. Who knows.

 

[OR VietVet]

Something to always remember, ECM can go bad but it is very rare.