89180sx

ok so previosly head gasket was changed than mechanical timing was out of wack car run on 2and3 than didn't want to start so timing cover was removed timing was adjusted now car runs on all 4 cylinders the problem now is when car warms up the idle loops from 500 to 800rpm and every few seconds there is a shake also when you drive at steady speed every few seconds car shakes but rpms are steady when i come to full stop prms drop to 500 and starts looping.The car has brand new air filter and new fuel filter doesn't seem that there is any vaccum leak. Another problem that occuring is when car is on windshield wiper goes on once nd clock in the cluster flashes 5 times and than clock desapears and it happens every time i start the car So can someone give me some gudies i am running out of ideas plz!!!!