Mosin Posted January 4, 2010 Report Share Posted January 4, 2010 Vehicle is a 2002 Pontiac Grand Am GT with the 3.4L V6. 100K on odo. The throttle 'bounces' or 'oscillates' between the RPM's of 1000-3000. At any gear 2nd and up. I don't know any other word to describe what its doing. It's not just the Tach thats bouncing, its the motor too. It seems to do it with a certain amount of pressure on the gas pedal. It began after the starter was recently replaced. What could be causing the 'bouncing' of the throttle? Quote Derp. Link to comment Share on other sites More sharing options...
Stephen Posted January 4, 2010 Report Share Posted January 4, 2010 IAC or TPS sensors Quote you can cook bacon shirtless if you're not a pussy...lol not hatin, but am i wrong here it looks as if the amp is not grounded its hooked directly to the battery. it that the way it should be. DC POWER Link to comment Share on other sites More sharing options...
Mosin Posted January 4, 2010 Author Report Share Posted January 4, 2010 IAC or TPS sensors Isn't the IAC only to help regulate the amount of air that enters the engine at idle? If I remember right..... And wouldn't a bad or faulty TPS sensor indicate problems such as hesitation or stumbling during acceleration? IDK if TPS and IAC problems vary from vehicle to vehicle.... Quote Derp. Link to comment Share on other sites More sharing options...
AR1684 Posted January 4, 2010 Report Share Posted January 4, 2010 i know some of the newer GM vehicles with the cableless throttle bodies have problems like this. not sure if an 02 has this throttle body or not. replaced one on an 06 malibu with 25k on the clock Quote Link to comment Share on other sites More sharing options...
bombout800 Posted January 4, 2010 Report Share Posted January 4, 2010 IAC or TPS sensors You need to try and take the filter and intake tract off. Check the MAF sensor for ANY debris. Actually get some MAF sensor cleaner and clean it anyways. Take the tract off. Inspect around the throttle plate(butterfly valve(s)). If there is any debris, discoloration, or anything causing it to hang or catch clean it!! Find something to snake in a little past the butterfly valve(s) to clean it. Make sure its nice and clean and crank it. May hesitate at first for a few seconds.... Then when it fires. Give it a few revs. Drive around to see if the problem still goes on. If not AWESOME! If so.. I would think the IAC and/or the TPS may be going south on you. Quote 03 350Z Link to comment Share on other sites More sharing options...
jmitch Posted January 4, 2010 Report Share Posted January 4, 2010 when i owned a car i had the same problems and found out all those thing work with 1 another. is ya car throwin a code if so see waht it is and ull find ya problem!! Quote I know a lil about everything so dont call me Mr. Know it All. Link to comment Share on other sites More sharing options...
Shyne151 Posted January 7, 2010 Report Share Posted January 7, 2010 I would try cleaning/replacing the MAF... I had similar issues with my 3800 and a new maf from the junk yard fixed it. You can actually try unplugging the maf(it will just run off a default table) and take it for a drive to see if it goes away... if it does you know it's the maf. Quote -Installer for Duke's Car Stereo 2000 Pontiac Grand Prix - Ported Eaton M90 S/C, 3.5" pulley, XS Power Headers, 1.9 Rockers, FWI, Poly Motor Mounts, Custom Tune. RF T1000-1bdCP and T400-4 Boston Acoustics SPG 555 Kenwood eXcelon 995 RF Punch 6.5" components and MB Quart Premium 6x9"s Powermaster Alternator, YellowTop D34, Vmax CT1000 Link to comment Share on other sites More sharing options...
Mosin Posted January 7, 2010 Author Report Share Posted January 7, 2010 I would try cleaning/replacing the MAF... I had similar issues with my 3800 and a new maf from the junk yard fixed it.You can actually try unplugging the maf(it will just run off a default table) and take it for a drive to see if it goes away... if it does you know it's the maf. That seems like a good idea. I'll give that one a try... The GA GT is leaking coolant which ruined the solenoid thus ruined the starter. It also has a tendency to drink oil. (About a quart a month) There is a possibility that the LIM gasket needs to be changed. I was told that with that gasket leaking while coolant drips out of it, air could be getting into the motor, through the intake runners thus entering the cylinders causing something like a bad vacuum leak. IDK if it has anything to do with the oscillating at mid-range RPM's though... Hopefully this extra bit of info can help solve the problem. Quote Derp. Link to comment Share on other sites More sharing options...
bombout800 Posted January 7, 2010 Report Share Posted January 7, 2010 this would def be causing idle/running problems. I'm surprised it's not worse man. Try to get it fixed asap. I know times are tough! Quote 03 350Z Link to comment Share on other sites More sharing options...
Mosin Posted January 8, 2010 Author Report Share Posted January 8, 2010 I would try cleaning/replacing the MAF... I had similar issues with my 3800 and a new maf from the junk yard fixed it.You can actually try unplugging the maf(it will just run off a default table) and take it for a drive to see if it goes away... if it does you know it's the maf. Wait a minute..... I had to think about this... A faulty MAF would trigger a CEL if I'm right... Which would have to be reset with a scanner tool which I don't have. Quote Derp. Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.