My car started doing this yesterday. It was the first really hot day here in NE so far this year. It got to around 89 degrees. But anywho, my car will kinda stutter when I try to get on it a little. If I am driving and I slow down for something to about 20 then step on it again, it will choke and sputter, then kick in and go. What could cause this. At night when it cools down, the problem goes away and it runs strong so it HAS to be because of the heat outside. Any ideas???

 

bad gas, combined with higher heat, causing some knock...and the engine is pulling timing?

it's not throwing any codes?

 

scan the car. Has the SES light came on? Could be opti, ICM, plugs, wires, coil, O2's/.....Mine did this, and it throw the SES light, turned out my o2's are/were running lean, and they are about to go..Best thing to do is scan it....

 

I put in a new opti about a year ago so I wouldnt think that is it. The gas should be good. Its the gas that I always get and it has never had problems before. I thought about changing my plugs and wires since I kinda have a rough idle every now and then. Any other ideas??

 

I had same problem 5 or 6 months ago and it turned out to be the Opti. That wasn't cheap either...

By the way, if you let it go like i did, then your car is going to start jumping in RPM's from about 200 to 2500 in about .2 seconds. This happened on the freeway and then my car stalled. Turned right back on but would just keep the RPM's jumping.

 

Yeah that opti was pricey. But I dont think thats it since I just changed that a while back.