My 1994 auto has had a long-standing problem. Sometimes it would fail to start - crank but no fire. The next day, it would fire just fine and I could drive it. Lather, rinse, repeat. Sometimes just driving along it would die (the most recent time throwing a service ASR light). Once this cycle starts, I evenutally end up with a dead opti-spark.

My technician may have stumbled upon the problem this week, and I'd like to see if you have some thoughts/guidance/expertise to assist and/or confirm that I'm fixed now.

Here's what we found (I say we, but it was all my technician dude, and I'll try to decipher all this correctly):

When he began working on the car this time, he did not have spark coming out of the coil. The first thing he tried was hooking up another good opti-spark to check for spark, and it was dark also. So he did a crank test. While having the test light hooked up to the hot source at the coil, the light went out at crank time. So we had continuity but it could not handle the current.

Leaving the test light hooked up - sometimes the light would be on, sometimes it would go off, sometimes it would come back on - all by itself. I actually observed the light going out just sitting there.

It turned out to be a weak connection at the bulkhead connector on the driver-side firewall - the hot wire to the ignition side of the coil. That has been fixed, and wiggling around on these wires no longer causes this intermittent failure.

This may explain the intermittent problem I've had with this car for several years. I'm certainly glad this problem is fixed. The reliability of the car should improve.

Here's where you come in: It's not clear to us that this condition could be responsible for killiing opti-spark distributors. I have had the car eat 3 opti-spark distributors. We're not seeing how this could damage an opti.

So, we may very well have fixed A problem. But we may not have fixed THE problem of the dying opti-spark distributors.

If you please - I would like to know your thoughts.

 

Was this issue repaired? If so, how was it done. I am having the same issues on my 95. Dealership replaced the Opti, Coil & ICM. Still same issues.

 

hm... odd... but logical.

think about it this way, the voltage comes back and the coil surges? Is that possible? The dwell is all fouled up, so it doesn't know what to do anymore?

I donno... thoughts.

I do know that the harness between the coil and ICM can do what you are describing. Those connectors go bad and that's that.

Glad I have the LTCC... 8 coils, no high voltage on the opti.

 

the wiring to the opti has one weak point very much related to the symptoms you experienced.

The low voltage wiring haness plugs vertically downward into the opti, the contacts are small and narrow. Everything above this connection eventually works its way downward into the opti connection; opti's get replaced but the wiring harness doesn't; this part of the wiring harness is about a foot long and retails for about $20 or $25.

 

AND I also replaced an Opti with a brand new expensive aftermarket MSD unit that was never right from the git-go. Drove me nuts till it finally crapped out and confirmed what I didn't want to believe; you actually can get two turkeys in a row!

 

I think you know this already, but just because you put in an Expensive msd optispark doesnt mean you put in a quality part.

Its well known here that there are problems with the msd optispark.

If it doesnt have the mitsubishi optical sensor, then dont buy it. if they dont have those anymore, then go to a junkyard

 

There are no problems with dying optisparks unless either:
A. You are using non oem parts without the mitsubishi optical sensor (ie you bought a $69 optispark from ebay, or paid $500 for an msd optispark which are known to be faulty also) and/or a warped reluctor disk.

B. You have a 92 thru 94 car without a vent. You need to either add a vented harness or convert to gen 2 opti (if you are doing a cam swap this is a good time to do it).

ac delco new old stock is what you want for a 92 thru 94
Delphi is what you want for a 95 thru 96.

**note someone told me delphi may not be using the misubishi sensor anymore so you will need to take it apart and check. If it doesnt have it, send it back. Try one from another source.

As for the new old stock: keep checking ebay, some old man somewhere has a spare. If you cant find new old stock then go to a junkyard and get one.

Take it apart, replace the cap/rotor, if there is a way to take out the mitsubishi sensor and reluctor disk then drop that into one of the $69 ebay china specials and you will probably have a great distributor.

C. Shrunk/cracked seals and moisture intrustion. Make your car run cooler (reprogram fans, 160 tstat). My car never runs over 175f coolant temp. Stock, id see 220f.
I had shrunk cracked seals on my oem 93 optispark. i made the car cooler running at the time i replaced it (for other reasons)) and ive never seen another shrunk or cracked seal.

I also run a bead of rtv silicone around the mating surface of the two halves of the optispark and electrical connector (there ws a hole there) as a further safety measure to prvnt watr intrusion

I am very happy with the optispark and think its crazy people convert to ltcc

 

Last time I replaced one on the '96 I got a bad dynaspark unit. I pulled it back off and installed the MSD billet with adjustable timing up or down. It has worked flawlessly for a couple of years now.

 

take a look at the 2 ignition mods. 1 might be going bad