Herb

I'm really getting tired of taking this car apart!
I've had this 93 C4 for about 21 years and for the first 17 years I had no problems.

Since then I have replaced 3. It appears that this one,an MSD one went out because of moisture and oil.

I pulled the engine and replaced all the seals and Gaskets except for the heads. Also changed the clutch and had the flywheel machined.
After some problems with a few sensors the Vette was back running strong!
A couple hundreds miles later, power is down and I have the dreaded H36 code and C25 code.
I failed to mention I had the MSD rebuilt by MSD.
Since it's a current code why is it always H36 instead of C36?
Even after I cleared the codes!
I have a Procharger so I have even more things to remove to get at the Opti.
I don't know about you but when the Vette is running bad I get in a bad mood and I'm sick of it!

Is there any other sensor that would not show up on the codes that could cause this power and response drop off?

Think I'll bring it to Cruisin the Coast and put a for sale on it!

BrandensBeast

We all know your frustration, and we all know you're not selling it

antfarmer2

O2s

Herb

Thanks! I replaced both of those also but with headers I might have burned a wire.

If if only it was that easy!

then again, why the H36 code?

Dt86

L98's rule!

dizwiz24

personally i feel that gen macarthur should have pushed north in china and shut down the communist regime that allows this $h1t to be produced for our market

aklim

Actually, WE (as a nation) are the ones that asked for it. We voted with our wallets by buying cheap crap. We asked, they delivered. Stop complaining. You want, you got. See all the requests for recommendations that use the euphemism "I'm not building a race car...."? It means "I want something cheap". IF you were really building a race car, you'd be consulting professionals which, from what I see, most of us are NOT.

Sears had Craftsman for forever. Now they have Evolv and some other crap. Why, if not to compete with what WE told Wal*Mart to bring in? Stop blaming the Chinese, Vietnamese, Nigerians, etc, etc. If it wasn't the Chinese, it would be someone else since we asked for cheap junk. We could have stopped it buy NOT buying that crap and it will dry up. As long as we, as a people keep buying it over good stuff we have to live with the crap.

Dt86

I don't think anyone asked for Corporations to drop American jobs for cheap overseas manufacturing. After they all made that move what's left to buy other than what they have to sell us? Maybe some of it is greed? I don't entirely blame the corporations for leaving. Hell all I have to do is look at my paycheck and feel raped by my own Government. They're to blame for not giving these corporations incentive to stay in America, keep American manufacturing and keep Americans working.

Herb

As they say in New Orleans,
Yeah, U Rite!

aklim

Ah, but Sir, buy buying all the crap up, we DID ask them. In fact, I'd go as far as to say we demanded that they do just that. Each sale they make, further affirms that it is the right decision to send it elsewhere and lower the standards. When I see my competitor do that and is successful, guess what I'll do next? When another business sees us doing that, what do you think they will do?

Let me ask you this. If there are 10 companies selling widgits and one moves to Timbukthree and gets them to produce junk and nobody buys that crap and moves over to the other 9, what do you think will happen? My best guess is that if that errant company doesn't improve the quality, there will be 9 companies left selling that product.

The time to act is not AFTER the companies have moved and to cry about not being able to do it. That is TOO LATE. The time is BEFORE they move. The Chinese can produce anything you want to whatever spec you want. You tell them you want cheap and to cut corners, don't blame them for what happens. You, by your purchases told the company which told the manufacturers. Again, sorry you didn't like the end product but you got to sleep in the bed you made.

Dt86

Which came first? The chicken or the egg? I don't necessarily agree that it's entirely the consumers fault. There are far more complex issues at play than that. But that's more for the off topic section.

aklim

Does it matter? That sort of thing is like 2 kids fighting in the back seat of the car and each saying "He started it!". Point is regardless of who started it, we could have ended it at any given time. So what if the big and bad company decided to move? Could you have not bought that company's product? Sure, you could but you didn't. When the next company moved, could you have not bought their products that were inferior? Of course, but you didn't. Now that most have moved, could you stop buying inferior products? Sure. Will you? Doubtful enough will which encourages further movement.

IF you can stop the trend but refuse to "just this one time", it's all you. Stop blaming the company, the government, the world, etc, etc. Unless a gun was put to your head literally, the purchase was made by you. The vote was cast by you.

Put another way. Can we stop the trend today? Yes we can. Can we pay more and buy higher quality products whether the come from Russia, Germany or Thailand? Yes. If so, the ball is in OUR court. What happens is on US regardless of who started it. I don't care who came first.

67Olds442x2

The "H" means History. Old codes are stored until battery power is disconnected. Also means malfunction has occurred but is not present now. Make sure the wires are good. I had my 94's wiring harness out and many of the wires were crappy. If the code comes and goes hence the H, maybe it's the wiring.

cardo0

Herb, i believe you have the first opti design which vents by itself. I swapped to second gen opti (along with my engine) and use the vented to the intake opti but still have replaced 2 of those but one was a O Reily/Cardone rebuild. The next AC Delco lasted less than 2 years. I read a lot of owners look for a original opti w/Mitsubishi optical sensor and swap it out into a new opti body. I sympathize you having to remove and replace the supercharger plumbing.

Something you could try for a cooler opti would be switch to sec gen opti and take a pressurized bleed from downstream the MAF (if you have one, i'm to lazy to look it up) and discharge to the intake somewhere behind the throttle blades. This could make more problems though as it would need to handle full boost (10psi ?).

Another option would be upgrade to 24X crank sensor and PCM. Yes a mountain of work.

Good luck and let us know what you find that works.

Modern Musclecar

First of all MSD opti's are junk, I've had 3 in a row bad right out of the box. Second why haven't you done an LTCC coil pack conversion yet??

cadmaniac

MSD's are not cheap. They should perform well, based on the cost!

And as fate would have it, I just ordered one....Sigh...Should I return it???


Where to get a decent opti?????

Modern Musclecar

From my experience MSD opti's are all junk, I would order an oem unit and install an LTCC setup. I've done this to every performance LT1 I've ever built and never had opti issues again.

Herb

I had a Delteq setup after the first Opti went out.
That latsted a couple 3 years until the part of the Opti that operated the
Delteq went out and I was convinced to go back to the stock setup.

When you read this article from Super Chevy's forum the MSD Opti
Sure sound good!

I don't understand why there are problems with them.

http://www.superchevy.com/how-to/vem...-distributor/#

Problem is, like the Delteq you still need an Opti for the LTCC to operate!

RedCorvette1988

In my 92 I used a Petris opti and havn't had any trouble at all.

cormorant71

I sold my LT1 because of the opti issues. Replaced a new unit (from a supporting vendor) within a year.

bought an L98 and LOVE IT!