Expert: Rob Painter - 3/24/2011

Question
My car is cranking but not turning over.  There is no spark so I had the distributor coil replaced but still nothing....what should I check next....oh and the check engine light has come on before this happened.

Answer
Hello,

I no longer remember how to check these old computer systems and they are old because the OBDII standard which is still used today started in 1994 on GM.

We used to just cross 2 wires with a paper clip on the computer diagnostic port below the steering column, but I no longer remember which two wires on the connector. Parts stores sell cheap code readers for this car and hopefully there is a chart that denotes what the code stands for. Once the check engine light comes on it stores a diagnostic code indicating what is wrong in the emission/computer system and this could very well be why the engine is not running.
If the ECM (Computer) blew up, you won't have spark or fuel. Instead of guessing, you need to find out exactly what is going on.

since the later half of 1980 GM started using computers. Computers changed everything when it came to diagnostics. Not always for the good either. These cars were no longer simple. Yes, mileage and performance was better, but so many people would replace perfectly good parts on a guess and not fix the problem.

Fortunately, a 1990 car has nowhere near the amount of sensors that a 2000 would have, but it is still easy to be baffled.

The good part about computer systems is that with the proper diagnostics, it is easier to pin point the problem from the onset. You cannot work on these cars in the blind though.

You are not alone. Everyone trying to save money tries to repair these cars themselves which is fine and a 1990 car does require specialized equipment for fuel pressure and other aspects, but in the case of not getting spark, the first consideration I would go to is to find out why the check engine lite was on.

Good Luck!

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