Hi,
This is a tough one. I suspect it is related to the TPS, but it just doesn't set a code. What really needs to be done is to have a live data scan tool plugged into the DLC and drive the vehicle while a helper watches the TPS signal for variations that could cause this.
I do have another question. When this happens, if I understand correctly the engine keeps running but doesn't respond to the throttle. Do you notice anything such as a strange odor, any smoke from the exhaust, any sounds, or anything that may help us figure this out?
The interesting thing here is the throttle valve is operated by a cable. Is anything loose with the cable? Also, have you checked the signal from the TPS? The TPS should receive a 5V signal from the PCM. At an idle, it should signal approximately 0.6V. At wide-open throttle, it should be very close to 5v. If the TPS fails, the computer goes into a pre-determined setting allowing the vehicle to continue running. But in that case, it should set a code.
Let me know anything you can think of. Also, please confirm that when this happens, the engine just idles and doesn't stall.
Take care,
Joe
Saturday, August 28th, 2021 AT 9:13 PM