Idle trouble

I have a 86 Marquis. I've changed all the filters and PCV. Whilst idling at a red light the engines shakes. Does anyone know why? Is the fuel mixture screw set wrong? Also when the engine does this and I start accelating again, I get a nice cloud of exhaust for a sec or two. Help?!?

did u try turnin the idle up from the throttle positioning screw?

Yep, the engine just shakes faster. Its now booked to go in for some service.

the idle air sensor or a vacuum leak could be your problem; see the thread for "stalls at lights" above.....I had all these problems which went away once replaced the parts....good luck!