Optispark is a great part mounted in a crappy location.

Make it work by installing a vented setup.

Don't make the mistake of using any aftermarket or remanufactured units.

If you have a 92 thru 94, you want the ac delco oem new old stock items
If you have 95 thru 96, I believe delphi made the oem units and they may still have new old stock.

No other optispark is acceptable for our cars. Its too critical a part to have fail

 

Who shoudl I buy an AC Delco oem new old stock item from?

Once I buy the optispark, I should purchase a separate vented set up...cap? Do I buy a vented cap for a new model like 95 or 96?

Thanks, I just dont want to make a $600 mistake in purchasing the wrong thing.

 

Very nice set up !

 

Man this optispark gets a bad rap. The guy wants to replace it because he fears it might go bad someday? That's like coming back from your honeymoon and filing for divorce because chances are it's going to happen, someday, anyway...really?


My optispark is going on 147K. At about 85K or so, it had the cap and rotor replaced when the Hotcam went in. Didn't need it, but just did it. I have had the water pump fail and leak on it. Have had the upper radiator hose bust at highway speed. The thing still works like it's supposed to. There have been a couple of times that I was afraid it was going, but always turned out to be other spark or fuel related issues. I wonder just how many perfectly working opti units have gone in the trash bin when it was something else that caused the problem.

It is a durable, well designed ignition system. As good as the coil on plug on the LSx engines? No, but if it were GM would still use the opti.

The important thing to remember is that the ignition system, the opti and the ecm work closely together. Changing that stream of communication is tricky at best. Going to the H.E.I. distributor is going back in time.

I've seen the Bailey LTCC website, and while interesting, to me it doesn't look advantageous enough to go that direction. Yes, it seems pretty simple, plug and play for the most part. But, from what I've seen, I bet that box is more vunerable to moisture than my opti is. Then there's the where to mount it issue. How will it respond to the high temps our engine bays reach? Will it last for 150K miles? No, if my opti dies, unless quality units are no longer available, I'll replace it. Chances are I'll be buried before it dies.

 

The Optispark does indeed get a bad rap, much worse than it deserves. When it works as it should, it's a superb system.

Having said that, the first-generation units definitely had their shortcomings in terms of durability. Given the cost to replace them, and the labor that's required, some of the criticisms are justified. The revised, second-gen units are vastly improved, and tend to last a lot longer. The OEM first-gen unit on my '94 died before the car had racked up 20K original miles. I replaced it with one of the original, DTE-built DynaSpark units, and it hasn't missed a beat since.

Many folks have had Optis that have gone well north of 100K miles. Unfortunately, many have had them die far too young, as well.

What's sad is that Chevrolet opted (pun intended) to go with the Opti, instead of the waste-spark system that they used concurrently on the LT5 cars. Given that the waste-spark system was available at the time the LT1 was being designed, and given that it was good enough for the King of the Hill ZR1, it's a shame that they didn't choose to use it on the LTx engines, too.

Live well,

SJW

 

This is an interesting GM vid about the inner workings of this system. Pay close attention to the part where they talk about the build up of nitric acid gases building up and corroding the electrodes, thus the vented opti II unit.

 

You might research this opti replacement..... high reviews:
http://www.petrisenterprises.com/ind...d=20&Itemid=26

 

I'm thinking of pulln the MSD box off and see what happens..

 

Personally, I think a quality vented opti is a pretty good unit. However, it is undeniable that mounting a conventional distributor at the rear of the intake would also do away with the problematic stub drive which drives the oil pump via the cam gear. At any rate, it would make inspecting those gear(s) so much easier (just pull distributor), rather than having to first pull the intake manifold and all the associated components. It would also eliminate one more potential oil leak at the front of the engine.

 

If anyone is curious - here are pics of the Pertis opti I purchased.
It arrived with all hardware, wiring harness, hoses and components required (as described) for an upgraded designed and install. The front face is a smooth glossy black finish - being blemish free. The pictures below actually shows a reflection on the face.

 

Well i got a line on a delteq system. Think i,ll dump the msd box and see how she runs.

 

Great pictures. Very nice assembly.

How long have you been running the Petris unit?

How well is it running?

Any issues?

Thanks!

 

Petris opti is great if you have a 92 thru 94.

But what if you have a 95 /96 (w/ dowel pin drive).....

All ac delco stock is remanufactured (for 95/96) and my genuine acdelco reman unit had a defective optical sensor. It would run for 2 min, then die.

Gmpartsdirect were cun1s about it also.


I think delphi was who made the oem 95/96 units. If you can find a nos delphi unit. Use it. I've had good luck with mine...


So moral to this story:

92 thru 94...use petris unit or nos oem acdelco modified with a late model vented cap and vent harness.

95 thru 96: delphi

 

Actually - the opti wasn't the problem with my 'always stalling when hot' issue. The short answer was the corroded wire within the wiring harness between the ECM and the MAP sensor. The continuity was compromised once the engine got hot that would drop the signal and cause the stall.

Was symptomatic of a possible half a dozen different reasons.

The PO never maintained the vehicle - a 20 year old/59,000 mile car with the ORIGINAL fuel filter (still have undercoating overspray on the filter). Had periodic DTC for TPS and MAP sensors. Replaced the TPS and checked (with vacuum pump) for MAP readings - nothing out of specs).

Since my fuel display was not accurate - started there. Replaced sending unit, fuel pump/sock, and fuel filter. Still was stalling - replaced injectors and FPR (ohm-checked the original injectors- and noticed widening range of readings). Idling improved - yet still stalled when hot.

Noted under checking signal readings - was low for the MAP signal from the ECM. Assumed the wiring was OK... had the ECM sent out for diagnosis to check condition of primary 5VDC circuit within the ECM (which was the source for many circuits, including TPS and MAP). The technicians had triple-checked the ECM and could not duplicate my described symptoms. Still had the same problem.

Replaced the plugs (spark gap .080-.090), wires (deterioration), IAC, coil, and ICM (replaced with all Delco/Delphi)... and noticed better fuel mileage... however still stalled.

Basically thru a process of elimination and past due maintenance that had to be done - the remaining suspect was the Opti. Fearing the worst and decided to finish the bloodletting, bought a NOS waterpump/Petris Opti, and sent the Corvette to a recommended shop (by my Corvette club) for the final answer (see short answer above).


At this moment - the car purrs; strong, responsive, young, and refreshed.


The opti will be addressed and replaced before next summer.

 

Thanks for your answer!

I appreciate your honesty in what was wrong with your Vette. Especially, because the dreaded Optispark was not at fault.

The shop you took your Vette to certainly deserves credit for finding that wire. Kudos to them!

 

Which makes a note to take. These cars are among the first generation of advanced computer controlled technology. They are getting up in years, and regardless of miles, things like wires and hoses are beginning to wear and fail.

So, when a system starts acting up, where we used to look at the mechanical parts involved, perhaps we will save ourselves alot of time and money, if we start looking at the simple stuff first, like wires and hoses, and seals. In these cars, a part will do only what the computer tells it to do and when. If the message doesn't get there, the perfectly good working part won't do it's job.