Pontiac Repair: RPMS surging up and down at normal driving speeds, mass air sensor, mass air flow sensor

Question
QUESTION: I have a 2001 Pontiac Bonneville SLE with the 3.8 V6. I just started noticing that the RPMS have started surging up and down in normal driving speeds. Any ideas?

ANSWER: Hey Herman:

does it isle smoothly at a stop and on a cold start up? Does the engine speed surge at all speeds if you try to hold it stead in aeach gear or does it only do it at cruising speeds in 4'th gear? try this if it only does it at a cruising spped when the trnamission is up in 4'th gear say 45 MPH and up hold the gas steady and just lightly depress the gas pedal makse sure no one is riding on your back bumper when you try this and see is the surging stops. If it does I would suspect a transmission torque converter cluth slipping issue. Has and service engine soon lamp come on when it does this?
Good luck :)


---------- FOLLOW-UP ----------

QUESTION: Sometimes I have to come to a complete stop before I can go or it surges up and down again.

Answer
If that is the case I'm now thinking more of an engine running issue. You could have a dirty mass air flow sensor that in the major engine load input for the engine computer. next time it's acting up unplug the snesor and try driving it. it will hesitate from a stop but see if the surging at speed stops. the MASS Air sensor is on the top of the throttle body it has 1 3 wire connector going to it the colors are pink/yellow/black. This will turn on the engine light when you do this don't worry about that. if the surging stops the sensor is either dirty or bad. you can try a product called mass air flow sensor cleaner made by a company called CRC it is in a red spary can take the sensor out and clean the sensor wires off with that stuff and try it again. just follow the dorections on the can. A can of that is way less then a new sensor. if you do indeed have a bad sensor do not go aftermarket on the party get a Reman unit from any GM dealer.