Engine Performance problem
1998 Other GMC Models V8 Four Wheel Drive Automatic 218000 miles
1998 gmc 6.5 turbo, disconnected batt's and cleaned terminals due to alternator problem. Reconnected batt cables, had hard time staring truck, driving down the road at highway speed and all of a sudden it would go into passing gear. Come to a stop and the engine would stumble then rev up. Don't know if it's the computer trying to reset itself or there is a problem with it. No engine servce light or codes.
Whenever you disconnect the bateries, the computer has to relearn what to do. It may be doing this now so you'll have to keep your eye on it. If it continues it may be a trans problem then have a trans pro run a scan onit.