HT4100 4.1, 4.5, 4.9 Discussion, car surges badly when stopping in Cadillac Engine Technical Discussion; after driving on freeway for short period of time and coming to stop car surges and tries to speed up, ...
after driving on freeway for short period of time and coming to stop car surges and tries to speed up, put in neutral and settles down, idles high at 1000 rpm or so. it is a 85 with the pig motor 4100 v8, anyone got any ideas on this???? thanks a bunch guys/gals.
Could also be stuck TCC solenoid. If you search this forum for TCC you'll find lots of info. I have this problem on my Eldorado. Easiest way to tell if it is TCC is to drive your car on the highway while in 3rd gear (and not in Drive). That won't allow the TCC to engage and the car will idle smooth when you exit the highway and stop. That'll be your clue. BTW, it is ok to have it in 3rd gear on the highway. The engine will just rev a bit higher and your gas milage will be lower. But you're doing this just for this test, so it's ok.
If you've checked everything, I'd pull the distributor and check the gear. You can just buy a new gear, you don't need a new distributor assembly. You simply punch out the pin on the bottom of the housing to remove it.