I have a 1990 Toyota Corolla with the 4a-fe motor, and 5-speed manual. Just recently the motor has been acting up and making some strange noises. First off, when i start it up, it almost sounds like its mis-firing then it smooths out and idles normal. When i rev the motor slowly in neutral it sounds perfect. as soon as i jerk or pop the gas, the motor shakes violently and sounds like a Subaru WRX. When i drive the car it almost feels like something is slipping. It only does it intermittently so ill be driving, with my foot on half throttle and it feels like i'm popping the gas on and off. I have checked the spark plugs, cleaned them. I have cleaned the contact points on the cap and the rotor. I went to the local junk yard and got another distributer and that did nothing. I changed the gas, checked the fuel filter. The only thing i can think of now is possible a sunken valve seat or a bad fuel injector. If anyone has any hint on what the hell this cars problem is please tell me. Thank you..
Danhole