a couple months ago. i had a pretty bad misfire problem with check engine code on. i had a tune up done. changed plugs wires rotor cap and car ran great for a bit. now. after ive driven the car for a while. a couple hours of stop and go it will misfire when at a stop or slowly accelerating under 5 mph. the car will shudder, buck, shake, the idle will jump between 500 and 800, a couple times it has stalled. if im at a stop and its doing this if i hold my foot on the gas and keep rpm around 1000 the problem goes away. there is no check engine on.
now. this is only after the car has been driven for a while and it is fairly hot. i use it for delivery so im doing alot of stop and go. turning the engine off and on etc. any suggestions or ideas would be greatly appreciated

thank you

 

Since you mentioned a "rotor cap" I'm going to assume that we are talking about a coupe here with a 2.5 or 3.0 L engine. If you browse the forum here you'll probably find that most of the problems with that engine seem to come out of the distributor. Other possible issues might be a bad injector, gummed up throttle body or vacuum leak. Given the relation to heat, I'd suspect the distributor. It contains the cam sensor and the ignition coil in addition to the distributor parts. People have reported bad results with aftermarket distributors.

 

it is the 3.0 after paying close attention this is what i can tell it is doing and when it is doing it. after a couple hours of driving. when i start it when it is already hot and been running for a while, the tach will bounce between 800 and 1200 and the car will finally settle at a normal idle after about 30 seconds or so. during this time when its searching for the idle if i put in in drive and give it gas it bucks. if i let the idle smooth out before taking off it is fine. once in a while it will randomly stall. once in a while when i step on the gas it will hesitate for a moment. it feels like the car has lost all power and then will take off. if when it is running rough if i drive a long distance, about 15 minutes or so non stop it seems to go away. again this only happens when its warm outside and after ive been driving the car for a couple hours. the other night it was in the 50s and the car ran fine all night without a problem. the next night it was in the upper 60s and the car acted up after a couple of hours

 

You ever figure it out mine is doing the same thing