Hello
I'm usually over in the C2 section but I need some help. A friend has a 96 with the gen 2 Optispark ignition. He has replaced the distributor 3 times. He says he gets about 3000 miles out of them. They keep failing. He has a shop replace them and the part has been covered each time under parts warranty, GM part, but he has to keep paying the labor. Is there an inherent problem with these or do you think the shop is missing something? I don't know if it affects it but he drives the car little and often has to charge the battery. Would high charge rate of a charger cause them to fail?

Thanks
Tom

 

The most inherit cause of premature optispark failure is moisture/ water damaging the inside of optispark. This is usually caused by a leaking waterpump or someone washing the engine and soaking the optispark. Now, from what I know of Optisparks having to replace it every 3000 miles is not normal unless caused by the above stated issues. Can you verify the brand of optispark, perhaps that may shed some more answers.

 

I can't believe the cap would be going bad in 3000 miles. What I don't know is what kind of failure he is having.

But going under the assumption the optical unit is going bad, I would want to know if it is a Mitsubishi optical unit. Some of the cheap replacements are using something else and having problems with units that are not Mitsubishi units.

Did they check for any water pump leaks and any poor pin connections in the connectors related to the opti.

 

3K miles is Definitely to soon! My original GenII lasted well over 100K. As stated above; water/antifreeze can be a problem.

- Is he washing down his engine by chance?
- Is he jump starting the car? ive read in the past were this procedure can cause electrical issues

 

Thanks for the replies!

I'll check on the brand of the unit and about engine cleaning.
He does charge the car often because it sits allot. I don't know if he starts it off the charger or not. I will find out. I will also confirm the symptom but I believe it is a crank no start.

Thanks!
Tom

 

Advise your friend to drive the car more, C4's seem to last longer and run better the more they are driven. They are such attention ****** its unreal.

with the above regarding the Opti-Spark especially a 96 Gen 2 unit. Something is amiss with this situation.

 

Ok. Symptom is always a no start. Car is parked running fine and some point later it won't start. Sounds like there may be an intermittent draw that pulls the battery down. Sometimes it sits a month and and it cranks and starts. Sometimes it has a dead battery and it has to be charged to start. It will start after charging. If it doesn't start the distributor replacement fixes it. When it does not start he has no tach activity while cranking. The water pump and coolant leaks have been checked each time the par5 is replaced with no issues found. He does not clean the engine. He says the distributor is an OEM part.

Thoughts?

 

With a near dead battery attaching a charger can easily cause a voltage spike because a fully discharged battery may temporarily present a fairly high resistance to the external charging source (whereas a battery that is just a little low will tend to pull the voltage of the attached charging source down). Some starter/chargers are far more likely to cause this than others because they produce a higher than normal voltage with a light load. Given the failure circumstances it is highly likely a voltage spike is damaging the optispark system.

Another possibility although it may not apply to the optispark system, is that some electronic ignition systems can be damaged if they are left powered on for a long period of time when the engine isn't running. Any chance a problem in the ignition switch or wiring is allowing power to be applied to the optispark when the ignition is off? This could be an intermittent issue. I am not sure what the normal current draw to the Optispark module is but it MIGHT be possible to temporarily insert a fuse holder in line to this module and when the vehicle is going to be off for a long period of time insert a fast blow fuse with a rating well BELOW the normal current so that it will blow if power is applied to the circuit when the ignition is off. This is about the simplest indicator to determine if voltage was present, for normal driving operation between testing periods just replace the low value (often sold as a instrumentation fuse) with a large value fuse.

Your friend is probably much better off with a battery maintainer if he doesn't drive the car often, it will be better for the battery and the electronics. One of the gel cell "jump" packs might be safer for jump starting than his current starter/charger but I would go with a good maintainer.

 

We considered the charging being an issue but did not know. One thing he does not start the car with the charger attached. He charges the battery then removes the charger before attempting to start. We also do not know if there is battery voltage to the distributor with the key removed. A battery maintenance devise is certainly a good idea.

Thanks
Tom

 

Tom,

You are welcome. I am certainly no expert on the Optispark system but I have spent a lot of time with electronics from vintage through modern. Given that it runs normally until shut off but then fails to restart after a period of disuse certainly sounds like frequent use of the charger could be causing the problem. A healthy battery serves to absorb voltage spikes and provides noise filtering but a discharged battery does neither well so the charger is a prime suspect. Don't bother trying to measure voltage spikes with a standard meter (either analog or DMM) because it is too slow to capture a "glitch" like this; an oscilloscope will display such spikes.

If something is discharging the battery intermittently because of power being supplied where it shouldn't then that could be the root cause.

All generations of electronics are subject to these gremlins. Shortly after I took delivery of my 2008 CTS I would sometimes find the battery dead after it sat for a few days. The dealer replaced the battery but it quickly happened again and the problem was found when I noticed that the status indicators on the rear view mirror were sometimes staying on after I exited the car; a power module in the trunk area was at fault.

Good luck on running down the issue!

Rodger

 

Thanks.
Any thought on aftermarket distributors like MSD? More robust than stock or junk.

 

http://www.petrisenterprises.com/ind...d=20&Itemid=26

MSD seems to be hit or miss. Lots of info out there on Opti-sparks.
Ebay units hit or miss. Some report good luck with Chandler units.

 

The link posted above looks like it attacks one of the key weak points of the factory Optispark unit. However your friend's unit is failing far more quickly than others report so a different unit might live longer (and it might not) but it is putting a band aid on the real problem.

I believe in finding the root cause of the failure because the same root problem could lead to the failure of aftermarket units. If it is a charger induced voltage spike it isn't doing any of the other vehicle electronics any good and more expensive failures could be on the way. The fact that the failure always occurs while the vehicle is shut off (or perhaps during the charge and subsequent start event) strongly indicates there is a causal link. If heat soak after shut off were the killer I would expect the Optispark to show some symptoms (i.e. an obvious miss) before shutdown unless your friend is running the engine at full load for several minutes before shutoff and manages to build up an incredible amount of heat-that is highly unlikely!

The good news is the only place it is leaving him stranded is in his own garage, that really beats the side of the road.

 

I think NSC5 has hit the most likely cause. I'm going to see if we can find a battery draw and suggest a battery maintenance device.

Thanks to all that replied. I am more educated on the system now.

Tom

 

Have you had the battery and alternator tested? How many volts are you getting on the digital display of the dash when the car is running? (Should be 13-14.3V) It wouldn't hurt to make sure they are both good, before you look at anything else.

 

Call Chris Petris http://www.petrisenterprises.com/ind...d=20&Itemid=26

He is one of the most knowledgable people on these problems and sells an optispark he redesigned with a vent kit..I've had it for over a year...