my 1996 plymouth voyager cranks but wont start checked the coil by jumping it and couldnt see any spark what could be the problem????

 

Could be bad coil but from a similar problem I had I would take the Computer control box to get it checked. It is the brain of the car. Mine would start sometimes and not other times. Maybe same day maybe next day. The computer box was going bad in it. I found a place that rebuils them. Had mine rebuilt and it lasted 3 days. Got my money back and old box from them and went to dealer and bought a new box for less than rebuild cost me.

 

It used to be, in the good ole days, that you could very systematically find out what was going on between the coil and distributor, and even before the coil.

First you had to find out if you had 12 volts going to the +terminal on the coil. Then if you did, you took another reading on the (-) terminal to determine if you were getting 12 volt fluctuation as you should (a pulsating of volts) from the dwell angle.

If you had no incoming 12 volt to coil, you knew to look BEFORE the coil.

And if you DID have +12volts, but no fluctuating (-)volts, then you had a distributor problem (like bad points, which would cause poor or no spark). And if both the + and - coil terminals were behaving properly, yet you still had no spark out of the coil wire, then either the coil wire was bad or the coil was bad. The fluctuating (-) terminal is what causes the 12 volt primary windings in the coil to build up charge during the certain phase of dwell, and create the transformed secondary windings to create 10,000 to even 50,000 volt charge (in racing coils)

But can anybody weigh-in here on if similar tests are performed on the newer cars, in basic same fashion, so one can pinpoint the problem without taking guesses? Personally I haven't had to try to make the diagnosis the poster is hoping to do on a newer style car engine (post-points era ) But the day might come.