tiddlywinkler on Nostr: That van should have a 4L60E with a lock-up torque converter. I wonder if the lock up ...

That van should have a 4L60E with a lock-up torque converter. I wonder if the lock up engagement solenoid is sticky. I'd think if the torque converter was slipping, you'd see the engine RPM go up without the van accelerating. When it's locked, the torque converter is not doing its torque converter magic, anyway.

Sometimes it can be hard to diagnose a bad engine mount. One way to check it is park at the top of a hill and have somebody rev the engine while you watch it from underneath.

But I think a lock-up clutch that was engaging or disengaging at the wrong times (or not engaging or disengaging at the right times) could cause those symptoms.