I get five OBDII codes: cylinder misfire 1-4, and multiple cylinder misfire (p030# and p1300). The car also shakes a bit when at a stop. If the accelerator is pushed all the way down, the RPM needle goes nuts, flipping to and from the maximum (although the engine seems fine and not actually going that much.) Also, when driving at about 75+ mph and about 3.25 RPMs, then RPM needle begins to fluctuate slightly. PLEASE HELP!!! I've been trying to fix this car forever.

Someone suggested it was the ignition control module (icm) and another one said check the throttle position sensor (tps). What do you think? These symptoms must point to a specific cause I would hope. THANKSS!!!

 

Forgot to say a couple things:

When changing gears, the car jerks a little.
Also, when the RPM needle starts to fluctuate, almost all the time the CE light begins to blink (indicating a misfire). The car also only gets about 21 mpg HIGHWAY. And, lastly, the car drives at about 2.75K RPMs while going sixty and begins to pass 3K RPMs while going passed about 67.

 

When looking at misfire codes it could be one or more of the following;
-Ignition system
-Fuel system
-IAC valve
-EGR system
-Bad fuel

However, with the erratic RPM symptom it points more toward the ignition system (distributor/ICM).

Edit.

Just saw your post about white marks on your computer. Has your car ever been in a flood or had the passenger side flooded by any chance? This could be an ECU issue.

 

Thanks for replying!

Actually I happen to know that it is not an ECU issue. I had bought a new one (the ne with the streaks), and all the issues stayed the same. No more issues came up and no old ones disappeared. So you think it is with the ignition then? I have just recently replaced the plugs and wires with new ones, and made sure the injectors were clean. I replaced the distributor cap with a different used one, I might try using a new one.

 

The tach receives it's signal from the ICM inside the distributor. Usually when the tach starts acting up it's a good sign that the ICM is going bad. Or it could be a short in the wiring.

There are tests that you can do on the ignition components instead of just replacing parts.

PM sent