2000 Pontiac Grand Prix GT 3.8 72K Miles
Car has a surging/pulsing problem. When running at highway speeds if I attempt a slight increase in throttle to overcome a grade increase car will surge. Can be seen on tach as it increases & decreases several times per second (I call it pulsing). After grade car runs normally. Vehicle has no other issues and no engine light comes on. Any help appreciated - Bob

I would check your pcv valve. The MAP sensor receives it's vacuum signal thru the pcv, and when the pcv starts to get dirty, it will cause part throttle/high load surges and hesitations before it get bad enough to trip a code.

Rich,
Tnx for the reply. I'll replace the PCV valve and report back the results.

Bob....

Did the PCV replacement fix your car ?
Mine is same car with 80K and doing same problem slight acceleration in 40-50 mph range causes surging that can be seen on tach too .

Any help would really appreciate !! THANX Dave

Did the PCV replacement fix your car ?
Mine is same car with 80K and doing same problem slight acceleration in 40-50 mph range causes surging that can be seen on tach too .

Any help would really appreciate !! THANX Dave

Sorry but please check the date and do not resurrect or slave off of old threads. Best to start a new thread/post to address your issue to the forum. Also, be sure to include the year Grand Prix, model or engine.

Your problem sounds more like a TCC related tranny issue aka "fishbite/"chuggle"or possibly a secondary ignition problem.

This thread has been closed.