I have an 89 Chevy Suburban 4x4 3/4 ton w/AT.  Sometime it will start and sometimes it won't.  Everything turns over.  It just won't start.  It acts like a car out of gas, but, there's gas.  Fuel pump works.  It just doesn't get spark every once in a while.  I replaced the Module, the cap, rotor, coil, etc.  The funny thing is that it's intermitant, It won't start and then I'll wait 5 minutes and rub the dash and talk nicely to it and bammo - IT STARTS.

HAS ANYBODY EVERY HAD THIS PROBLEM WITH THIS PARTICULAR CAR OR SIMILAR CHEVY OR GMC??

IT'S DRIVIN' ME CRAZY.  I can't go off roadin' and feel safe.

maybe? in a plymouth 91 model it would spit a sputter some or not start it ended up being an electronic piece in the distributer.  But what is the chance of a wire around the distributer or a bad connection some other wire there cannot remember for certian what my chevy distributer looks like inside but one of the wires that go into the side under the edge of the cap may be grounding out sometimes.

Have you checked the trouble codes? Sometimes the ECU store trouble codes even if the CHECK ENGINE LIGHT is not on.  The computer might be able to tell you what is wrong. The sell a diagnostic code reader for about $40-50, or you can just use a short jumper wire to short the top two terminals on the upper right of the diagnostic port just under the dash below the steering column (the diagnostic terminal (B) to the ground (A)). With the ignition switch on, the check engine light will flash (one flash, pause, 2 flashes = 12) any codes that are stored. Refer to a Haynes manual for a list of al the codes. You might try disconnecting the battery for a few minutes to clear the ECU, then try to start your engine, then check codes again.  

I have checked the codes and there are none stored.  It has been running fine for the past week, so I haven't done anything else.  But, today, and of course, on the way to my daughters soccer game, it did it again.  This time it didn't start at all and still hasn't.  This is actually good though.  At least I can now try to chase down the answer.  I am going to start by replacing the distributor (Complete)  A few months ago I replaced the module and the pick-up coil along with the ignition coil and cap and rotor.  The coil tested good, but the pick-up coil is kind of iffy.  I am unable to test the module because I don't have the equipment.  Since the prices to replace these and put them in my existing distributor is only slightly less than the price of a whole new complete distributor, I am going to replace the distributor.

Does anyone else have anymore ideas, If this doesn't work do I replace the ECM?  They're only about a $100 but, the thing that gets me is that I can't figure this thing out.  If it was an older car from the 60s-70s I would have no problem at all.  Isn't technology wonderful???

Thanks!!

LOL  My method of working on newer CPU controlled vehicles is to randomly choose a sensor and replace it. Usually after I replace all the sensors I finally find the right one. Hope I helped. LOL  

Yes, I have the same problem, and I know I have a weak spark, but I don't know why for sure. My solution is the same, i.e. new dist. from accel. Let me know if it works for you. I suspect the coil is not getting the proper voltage, it needs a full 12v from the ign. hot solenoid post. If it doesnt get 12v it will not spark properly. Mine only runs until it gets warmed up, then dies.  

I did change the distributor and it works now.  But we'll see how long it lasts.  I'll keep everyone posted. 

As far as the replacing of the sensors.   I have a very hard time just replacing things randomly.  I like to know the why, how, and inner workings of things.  I hate replacing something when I'm not sure whether or not it will work.  I did test the coil, it's ok - the pick-up coil-it gave some wierd readings - it fluctuated -which makes me think that this was the culpret.  I can't check the module because I don't have the equipment that the dealership has.  So it could be that too.  Since I've already replaced them once and I'm back to square one after a few months.  I decided that something inside the distributor (off balance - maybe a shimmer in it) could be causing them to go bad.  Also if you don't put the right kind off grease under the module it will get hot and fail.  That could be it.  We'll see.

Thanks for the suggestions.  I'll let everyone know if it continues to work.  It's been two days and still working.

Thanks.

Auto Zone can check your ignition module and many other sensors for free, that might help track down the offending part  

Hey everyone, It's still working and it's been almost 2-3 weeks.  I think that I got the culprit, I wonder whcih component that it was.  The Ignition module (likely), the pick-up coil, or the coil itself.  Next time I'll take the module to AutoZone to test.

Thanks.