My brother has had a misfire and detonation problem on his 94 Corvette LT1 for some time, the misfire was particularly noticeable when revving the engine whilst stationary, the detonation particulary under hard acceleration once the engine had warmed up to over 195 degrees. He replaced all the plugs and wires which did not help at all, but shortly after we noticed that the coil wire was arcing from the opti every now and then, to the engine, which was accompanied by misfiring.

We came to the conclusion that the opti was'nt transmitting spark.

Long story short, we replaced the stock unit with an MSD cap and rotor.

My brother then took the car out for a test drive and the problem was apparently cured, it reached peak temperature and remained fine.

However on returning home the engine began to stumble. The steam coming from under the bonnet led us to realise that we forgot to put the clamp on one of the coolant hoses properly, and the coolant was spraying out of the hose connection and basically dousing the entire front end of the engine. Everything got soaked.

We put the clamp on properly, squeezed 3 liters of water back into the system and ran the engine again. Now the misfire when revving has returned, and we can just about hear a hell of a lot of arcing from around the opti area, it is very quiet arcing not loud like the initial arcing before the cap and rotor swap.

My question is could just getting the plug wires wet cause this problem, and is there any chance the coolant will corrode the opti-ht lead connectors? We blocked up the vent holes on the opti with RTV and used the vent hoses that came in the MSD kit, it should otherwise be sealed. Is it just a case of letting it dry out?

This is not a fun result after 18 hours of taking the effort to swap the thing, only to have the same problem return by another means.

 

Given what I did to mine (basically also giving a coolant bath to a brand new opti) it should probably just need to be dried out.. give it a week or so and I'm sure it'll fix its self.

 

I think it just needs to dry out, let the car idel for a while (if its cols out side point a blow dryer at it for a while but not to close to it)


If that doesnt fix it then at least you can just return it and get another one for free.

 

Wow, it sounds like you have about the same luck that I do

I highly doubt that the coolant worked it's way into any of the plug wire connections, as the rubber boots fit pretty snugly and keep moisture out. I'm not familiar with the MSD optis, but I would suspect that the inside of your new opti is wet, no matter how well you sealed it up.

I would just let it dry out and see what happens. Try again tomorow.

 

I thought this as well, the plugs push downwards onto the connectors so if the connectors did get wet then the water will have had to have gone uphill.

Is there any chance that water on the leads could draw spark through the lead insulation?

He's taken the car home now, and will be away for several days (He's on eggshells about this and I don't blame him ). I did suggest that he ran the engine for a bit to help warm things up, it is cold here at the moment.

As for sending it back for a free replacement, check my location.

 

Yes, that sounds logical to me.

 

pull the plugs wire and coil wire off the opti and give them a good wd40 or water dissplacer bath. the soak the opti in it also. cured me with a similar problem.

 

I work down the street from MSD, and they blow I refuse to buy MSD products ever.

 

Ethylene Glycol on plug wires will wipe them out. Can't say for sure what it may have done to the opti. If it were mine, I know what I'd do.

 

I have had many good experiences with them on fixing thier products. I have had a couple of MSD boxes, coils, and even a set of wires replaced for free. Give it try.

 

One of the main paths for water/coolant entering the Opti seems to be through the harness connector tower. That seal apparently deteriorates and breaks down.

Have you pulled the harness connector off, and check for corrosion?

 

I started this thread about an hour after it happened, I don't think corrosion will be an issue just yet. At least I hope not.

As for the Ethylene Glycol on the plug wires, would the best course of action be to pull them out and rinse them off? Is there anything else on the engine that might suffer from the coolant?

I thought it might be an idea to just hose everything off as it is, but then again maybe the opti has had enough of that already. I notice that coolant seems to take ages to dry up so I'm a little worried that it might do more and more damage the longer it stays there.

 

I'm not suggesting that the recent leak corroded the connector.... but getting an already corroded connector wet can cause problems. Corrosion of the harness connector is very common. One of the advantages of replacing the complete Opti, rather than just the cap/rotor is getting a new, sealed connector tower.