I'm new to Corvettes. I bought my 94 about 2 months ago. As I browse this forum, I see a lot of bitchin' about the Optispark.

I have a 96 Impala SS that I've owned for 12 years. It now has 246K miles on it. The Optispark has never been worked on.

Is there something, besides changing the plug wires, that I'm supposed to do to it that will make me want to bitch about it too?

 

That is funny. From what I understand they were improved for 95 and 96, but prone to moisture problems before that. Even the improved models are expensive to repair. But all this info is from memory of what I have read, the one in my 95 is working fine at 109K. I am sure more people will show up w/ better and more info. I hope.

 

I can't 'splain it to you. I have an Impala with almost 250,000 miles on the original. I have changed cap and rotor. My Vette has well over 140,000 and it's still original. Maybe we're doing sumpthin' wrong.

 

shhhhhhhhhhhhhhhhhhhhhhhhhhh............ ........................

You will wake up the Optispark haters!!!

125,000 on my LT4 and only a distributor cap & rotor replacement at about 90,000.

The Optispark Distributor is definitely the most maligned part ever commissioned by GM.

SAVE the WAVE!

 

I doubt the Opti just fails anymore than a common ICM....the problem with the Opti is that they HATE water and when they get wet and go bad...they go bad all the way. No sorta runs bad, or gets better when hot...it s dead burp, gone.

The COST is what gets folks so upset and looking to lynch a GM engineer.

 

I think this is a reflection of the "squeaky wheel" paradigm. The people who don't have any problems (the vast majority) don't complain.

 

Gm recommends replacement at 60k so if you go over your not allowed to bitch.

 

I have had a bunch of LT1 cars and never had an optispark problem.

96 Z28 w/55kmiles
96 Caprice w/90k
96 Impala w/110k
95 Caprice w/132k
94 Corvette w/25k
94 Corvette w/145k

The Z28 even lost a water pump and was dumping right on the opti.

I think the optispark problems are blown out of proportion. Yes there are some that fail, but realistically it is just a distributor. If it fails then make the repair.

 

Over 110k on my non vented optispark. Had a waterpump leak on it but I caught it early, and its still running just fine a year later. Granted, I took the high voltage out of it and run LS1 Coil Packs - I did this when I got overly frustrated by ICM/Coil failures, primarily from using aftermarket parts of questionable quality. The LS1 coil conversion has been bulletproof so far, its never missed a beat and the spark plug wires are easily accessible. Still using the original optical parts without issue.

 

For every Opti "issue", there are thousands of non issues.
Approx. 118k miles on my '96 and no issues. Still on the original Opti.

That is interesting. I've never seen that. Where did you read that?
Is it listed in the FSM or owners manual?

 

let me AXE you a question:

Does your 96 have a vacuum vented optispark (one hose is a filtered air inlet drawing air from a safe, dry place, the other is a vacuum hose)?

Does your 94 have a vacuum vented system?

If yoiur 95 is vacuum vented and your 94 is not, that could explain why one lasted much longer.

Im one of the few on here who like the opti-spark. I studied it and learned to understand its weaknesses. Once people understand its weaknesses (and how to counteract them), its actually not a bad unit.

I had to replace my original optispark at 26000 miles. So I bought a genuine GM ACDelco optispark (dont trust the knock-off's) for my 93 and put a late model 95-96 vented cap on it. I drilled out one of the three weep holes at the bottom of the base and inserted some vacuum tubing into there. Connect that to a vacuum source off your intake manifold. I expoxied the other 2 holes shut. I used the cap's hole as the air inlet source. Some people connect this into their air inlet tubing, downstream of the air filter. This is a safe place to draw clean, dry, filtered air from.

Also, seal that cap (both the base and cap) with RTV silicone so that no water will get in there if the seal breaks (very common) or around the electrical connector into the optispark.

Also, make sure your vacuum inlet tube is a smaller diameter than the air inlet to ensure that you wont draw more vacuum then your air inlet tube can handle. Ive heard its possible for the optispark cap to collapse if that happens or if your air inlet were to get clogged.

No issues 35000 miles later.

Optispark can reliably light spark beyond 7000 RPM.

 

Thanks Diz, you're right. I've repaired about 20 Opti's for people over the years. I have a test rig setup for the optical sensor. I've seen one absolute sensor fail and the rest were contaminated. (Dirty) I don't know for sure but the contamination looked like an oily residue.

Possibly the air inlet hole is getting clogged and the vacuum is drawing an oily mist in through the bearing seal. If that air hole clogs I also know that the vacuum will suck the cap in about .090. Vacuum and dial indicator proven. Think of the cap as a big piston. It doesn't take much vacuum to make a lot of movement.

I've got a plastics cleaner that cuts oil (Kinda like carb cleaner for plastic) and all I do is spray the crap out of it and clean with cotton swabs. Reassemble the opti and go for another 100,000. Since the LED's in the sensor are typically rated for 50,000 hours, if you drove 3 hours every day they would last over 40 years. It's not usually the electronics. The sensors must be kept clean because they have to be able to read the leading and trailing edges of a slot about an eighth of an inch wide. That's a pretty quick response. Dirt is a no-no.

 

Don't stress becasue a few people here hate on it everyone panics. Yes some have failed, but so do distributors and countless other parts in cars. You never hear from the 200,000 people who had no issues or the guys who went out at 100,000 miles and said hey not bad, got it changed and went on with life.

From an engineering standpoint at the time it is actually a pretty neat little bit to put it technically.

 

hey dizwiz24 and1963SS , i caused my opti to fail by pouring water on it. did'nt know that was a bozo no-no! cleaned the alt bracket and corner of the valve cover while the alternator was off for rebuild. after drying the opti out the car runs but backfires like crazy at low RPM under accelleration. my question is , since the car still runs , the optical sensor must be good , do you think cleaning housing etc. and installing new cap and rotor will work or replace entire opti? its a 92 coupe without a vented opti.

 

if it wasnt very long ago then maybe..

If its all rusted and stuff, then you are out of luck.

 

Yep, I'd bet that it's just got some crap on the sensor, condensation, oil, water, etc. If you clean it well I'll bet it will be just fine. Don't soak the sensor just clean it well. You'll need to remove it. While it's out gently clean the wheel also. Get a new cap and rotor (The MSD works well) and reassemble.

 

thanks! dried it out with industrial heat gun the next day. if its not too ugly i will clean and install new cap and rotor.

 

Really ?

 

Like many early versions of auto parts (early T700 was typical ) they had problems and weaknesses that were overcome by better design but the bad reputation continued as gospel.

 

Depends how the car is used.

- Sitting can kill them....condensation and corrosion
- Extended high rpms can kill them...rotors grenade, rotor screws back out
- Corvette owners love to power wash their engines, and the moisture kills them

Drive the car like a normal car and maintain it with some reason of care, and the Opti will last a long, long time.