Missing

thunder89

Registered User
My '89 SC has an ignition miss. Occasionally the car will run smoothly for a few minutes at a time. I have tried replacing the plugs and plug wires, but that did not fix the problem. The miss is usually accompanied by incorrect tachometer readings, or wild swinging of the tachometer needle. Should I try replacing the DIS module? What other causes could there be?
 
Describe the circumstances where the miss occurs. Is it always, or intermittant?

Replacing parts in hope of finding the problem rarely works.

The DIS controls the ignition system in general. It wouldn't be my first thought for a miss that is isolated to one cylinder.

I would certainly get a timing light and work to narrow down the miss to one or two cylinders.

If it's two cylinders, depending on which two, it may point directly to the coil pack. Our coil pack has 3 coils with 6 connections. Each coil fires two cylinders. When one cylinder is fired, the other is on the exhaust stroke.

Are there any codes? Check engine light? I would reset all of the connections on the Crank and Cam sensor. As well as reseat connections on the DIS and coil pack.
 
Since you mentioned that the tach goes way wacky that just screams of either Cam Sensor or DIS. I'd say it's highly likely it's one of those 2.

I'd start by replacing the cam sensor (since it's only like $30 or so and about 5 minutes to replace yourself). If that doesn't fix it, then it's your DIS.

Dale
 
Back
Top