ongoing problem ...make that 4 years.

On my '89 vette, over the past 3 years there is a funny problem - I have been working at it all this time ...plus I gave it to the dealer for a few days and also pep boys. The dealer was smart enough to say they couldn't find the problem and pep boys changed out most of the ignition components and did not fix the problem.
There simply appears to be no spark when starting the engine sometimes. The real problem is that it is intermittent - it fails about every few months or so. The engine turns over but will not 'ignite'. If I wait a few minutes to a few hours, it will start. The distribuor, harnesses, ignition module,cap,rotor all has been replaced.

Now here's the key - if I take the distruber off and regrease the ignition module (ignition module di-electric grease) it always fixes the problem and fixes it for at least a month or so. Now I carry around the few tools I need to do this - but the question is "why does this fix the problem?" Am I just doing something else that seems to fix it. Does the electrical contact grease have to be special (using high-temp 3M ignition module 'clear' grease).

Any sugestions or insights would be helpful - also considering it to be intermittent - is there anything else I can check when the problem occurs again to isolate it. I was able to confirm that no spark was present when the problem occurs.

thanks,
barrypaul

I've had a few good suggestions but nothing that's solves the problem. A few more times I've had the problem (including yesterday). After I take off the distruber cap and regrease the ignition module - it works fine for another 2 months or so. I have noticed only one correlated symptom (besides verifing there is no spark present at the plugs when this occurs) and that is the sound the engine makes when it turns over. I could almost predict the ignition problem by listening to the engine turning over and it sounding very dull. Instead of a Rrrrr Rrrrr Rrrrrrr ...it's more like a steady rrrrrrrrrrrrr. This may be do to the spark not being present ... but it could be related to the source problem. Any more ideas out there ... or any similar problems that would make me feel like I'm not alone.

thanks,

 

Intermits are the toughest. Your best chance to find the culprit is when it won't spark. First check if there is 12v on the pink wire (from my 87 manual) which comes from the ignition sw. I doubt that the removal and replacing of the spark module has anything to do with your problem except for an intermittent spade lug that plug into the terminals on the spark module. I would replace all of them. I would also consider replacing the pickup coil which might be the cause of the intermittent. Hope this helps.

 

Maybe an intermittent connection at the elec connector to the distributor.

 

I'd be suprised if jfb hasn't nailed this one. If the pickup coil hasn't been replaced before, do it.

I'm a bit miffed about the different sound when it won't start though. Is the starter engaging? It's rare, but the solenoid can fail where the pinion won't completely engage, yet the contacts for the starter still make. The start turns, but engine doesn't. The engine is turning when it won't start, right? Just had to ask!

My bet is on jfb.


[Modified by Ray Quayle, 10:54 AM 5/18/2002]

 

Vats?

I had a similar problem on my 90. Mine turned out to be the module. When they replaced the distributor the pickup coil should have been changed. If you have a test light I would check for B+ at the distributor. Take off the coil cover if you have a stock coil. and connect the test light to one of the terminals the red wire goes to. This will help rule out the ignition switch.

On to Mr. Vats. I have heard that the early VATS pre 90 has some issues. You may wish to disable that bad boy and see if the problem surfaces again. With a VATS problem the car will crank but not fire. Heck even try this the next time it happens. Stop cranking. Get out Lock the doors. Shut the doors. Unlock and open the door. Get in and try it again. If it is VATS this may get you going.

Good luck,

V


[Modified by Weird Vettaholic , 12:33 PM 5/18/2002]


[Modified by Weird Vettaholic , 12:36 PM 5/18/2002]


[Modified by 90_roadster, 12:37 PM 5/18/2002]