bad idle

ok i have an old 1992 4cyl. corsica 245,000 km on it ,its still alive but the only problem i have is when i turn it on, it run so rought as if the motor is going to pop out but when temperature is colder outside it kinds of run better meaning the idling because when driving it runs beautifully, when arriving on a stop it starts again shaking,no engine soon light coming on had spark plug and cable change,injector clean,the problem is only when idling i;ve seen posting about coil pack but would that part work better when driving and defect, on idle , if you guys have an answer i would appreciate it but would more if youre would suggest me what part and what that part does so i can understand the function better. thks all JUST LIKE TO MENTION THIS CAR IS A LEMON GOT IT NEW GOT TRANS. REBUILD MOTOR REPLACE CAR REPAINT DEFECT PRIMER ABS BREAK NEVER WORK, I ATE IT SO MUCH ITS $^%@^ BUT CAN'T AFFORD ONE THIS MOMENT THIS CAR HAS BEEN BUILD ON A CANADIAN FRIDAY.

First guess would be the Idle Air Control, which will carbon up badly on these cars, or a vacuum leak. Romove the IAC and clean it(don't push the sping in, just clean the end of all carbon) and the area it connects into. With that many miles it probably needs cleaned badly if it never has been before. Vacuum leaks, just check all hoses, and make sure no cracks, splits in intake rubber hose. If the ignition module was bad it would have weak spark and be hard to start on damp or cold days. A coil COULD be failing, but need to check spark on all four cylinders to figure that out. If they are easy to get at you could remove them(coils AND module) and have them tested at Advance (at least the module) and the coils can be tested with an ohmmeter when removed. One thing that is common on these 4 cylinders is failed head gaskets, head bolts, and cracked heads. Could be loosing compression on one cylinder. Get a compression test to see about that. If you are loosing coolant that could be a sign also. Since you are not getting any trouble codes I cannot think of anything else off hand...