Car "bucks" when heat soaked

[rob350]

My car started doing this earlier this spring. When I get in traffic, or park it when the engines hot, the car will start bucking/stumbling right when you start to push in the throttle. As soon as you push it down more, it clears up and runs great. Once you start moving and the car cools off, the problem is gone. Something is getting heat soaked and I think it might be my mass air flow sensor. I replaced it last fall right before I put it away for the winter with one I had laying in the barn and I never really drove the car with the new/used one. Does this sound like the problem? My TPS/IAC are in spec.


Thanks,

Rob

 

[83ttypecooled]

stumble

Hi,
Are you certain the tps is ok? It takes no time at all for tp sensor voltage to drop to idle or 0 on tip in throttle. That is where all the wear occurs on the potentiometer contacts. Without a graphing multimeter, you will never see the glitch. It will often not set a code 22. The sensor is cheap and easy to change.Why not give replacement a try? Good luck with your trouble.

 

[87gninpa]

TPS is possible, but as 83ttype said, it is very hard to detect with a normal scantool. It could also be the MAF as you stated, but I had that issue and it turned out to be an ignition module/coilpack (replaced both at same time). When one or both goes, its usually more noticeable when hot.

 

[mongoose87]

I had that problem

Hey bud I had the same issue, and it was my Transmission silenoid its about a $30 part. Good luck