[noluckwithcars]

I have been experiencing misfire problems with my Nissan Altima. I have changed the plugs, air filter and just a week ago had fuel injector service done.
Car still misfires. The only things that seem to be consistent is that it happens after a cold
Start. Sometime the car idles rough.. actually shakes.. this though goes away if I let it warm up enough. Sometimes I can be stopped at a light and the engine is so quiet I can hardly
Feel it.. then it suddenly shakes.. then stops shaking.

I have never stalled or failed to start. On two or three occasions when the misfires started
I parked the car , shut it off and restarted after a minute. The problem went away and did
Occur again until the next cold start. The misfire has never occurred when I start a still
Warm engine. Gas mileage does not seem to be affected.

There was one time that this happened and I parked the car and I could swear that I smelled an odor very similar to that of a burnt circuit or wire. But that could just be my imagination.

The car is getting very scary to drive. I really need to solve this problem.