aivanjp

my 1994 corvette is shutting down completely when the temp reaches only 180 to 190 degrees, new water pump, radiator has been removed and cleaned, it runs perfectly in the driveway but when i take it on the road it dies. left me stranded twice.

billschroeder5842

Could be a lot of things, but the usual culprit is the Opti spark.

Actually we really need more information; Any codes?starts and idles ok? any symptoms prior to shut down?

aivanjp

The car runs fine when just sitting in the driveway. I had the optispark replaced a year ago after a water hose split and water got into the distributor they replaced the water pump when they replaced the optispark.

aivanjp

No symptoms prior to shutdown it just shuts down - pull over to the side of the road and sit there. It was restarting and cycling off and on - car would drive for a mile or so - but now it won't restart at all until the temp drops down below 150 or so.

Drifter36

I replaced my opti a few weeks ago because of similar symptoms. But my engine threw a dtc16 which is certainly related to opti failure.

Do you know what brand opti was installed?

aivanjp

I have no idea what type of options spark is is installed. Is there anyway to check?

Drifter36

I was more curious as to which brand may have failed. It's hard to visually tell which brand was installed.. I think MSD has a red housing..
As a first step, You should have the engine checked for any diagnostic trouble codes that may have been generated.

aivanjp

I'll try and see if it is throwing any messages

billschroeder5842

This would not be the first time that a "newer" part failed.

Did you wash the engine recently perchance?

aivanjp

No, I didn't wash the engine recently. I am aware that could cause problems with the opti spark. I am stumped.

Palanon

May be a bit obvious but, when cleaning the radiator, did you check the cap. could be as simple as that. Don't think it would throw a code, either. Do you know how to check codes?

NavAir

OP's problem relates to temperature-related shutdowns. Nothing with the cooling system would cause this. Could be Opti, but I would bet on injectors, particularly if they are originals. My '89 had this exact problem, no codes, simply would shut down when it reached operating temperature. The injectors can have internal shorts, which manifest when they get hot.

Steve

aivanjp

I haven't changed the radiator cap but that's cheap so I'll try it. Thx.

NavAir

I must be missing something...

Why would you think that anything having to do with the cooling system is at fault. Your temperatures are normal when the engine dies. And even if the car was overheating, it wouldn't kill the engine. Since there are no codes, the Opti is probably good. I say again: Check the injectors...

Steve

aklim

Isn't he past that issue? I thought the injectors were no longer Multec junk by then?

NavAir

True, but if he has original injectors, they are 22 years old by now, and you still could have a short.

Steve

aivanjp

If the injectors are the issue would the car just shut off or would the engine cough and fart before shutting down.? It shuts off instantly with no skips or anything.

NavAir

Can just drop dead (thats what mine did). One shorted injector will kill the entire bank (they are wired in parallel). Your engine won't run on 4 cylinders...

Next time it dies, just pull the injector wiring connectors. Measure resistance of each injector with a VOM. As I recall, 14-16 ohms is normal for stock injectors, below 10 ohms is bad, shorted will be close to 0.

Steve

aklim

Good point. I'd just get a reman set at this point since they are probably crudded up to some extent after this time

aivanjp

Ok I'll try it.