C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Another bad optispark???

Old 05-15-2019, 04:04 PM
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Default Another bad optispark???


1993 Lt1 18.500 miles.

With a medium to fast movement of the gas pedal, the car accelerates fast and hard until it reaches 4800 or 4900 rpm, from that point it continues to accelerate but much more slowly while hesitates giving gentle pulls.
But, if I accelerate it slowly and smoothly, the engine reaches the maximum rpm without a single miss.

What I tried:
New coil
New coil wire
New Bosh III from FIC
Fuel pressure is correct on all ranges, even at WOT.
Spark plugs and wires are 10.000 miles and they seem fine.
No fault codes.
I also tried another ECU that I have as backup (same chip)

The car turns on at the first touch of the key, either cold or hot. Idle is smooth.

Despite the few miles, could the optispark be the cause? During my ownership never got wet. I never washed the engine or drove the car in the rain. No coolant or oil leaks of any kind and what I see of the opti from above is clean and shiny.

When hesitating, the tach never goes crazy.

Can an optispark fail because of age rather than use?

What else can I try before finally blaming the bastard?


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Old 05-15-2019, 07:41 PM
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I have a 93 bought new opti rusted inside due to water pump leaking slowly on it Car was garaged since day 1 only saw rain once. I had no codes at 16000 miles and that was last year. Never over heated (could not believe condition of pump frozen pump shaft) The only indication i received was bucking when full throttle was given and no power. If your opti is stored inside in a controlled enviroment it does not matter. If it is the original or even a replacement this is normaly the problem. If you have your original there is a gentleman who repairs them on this forum.
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Old 05-15-2019, 08:52 PM
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Thanks for your answer.
Years ago I put a small hose in the weep hole of the water pump. I always keep the car garaged and the temperatures arround here are not extreme. The car has the original opti, and despite the few miles and all the precautions taken, all indicates it is the cause of the problem.
I know of the Optidoctor through this forum and I am aware that he repairs and sells optisparks with the Mitsubishi sensor, but living where I live, is very difficult to send the part to be repaired and then recieved it back.
Next month I will be in the US for 5 days and the options are to buy and send to my hotel a complete opti from this guy or to buy the vented cap and rotor from MSD (in the case my optical sensor is ok).
From your experience, how was the optical sensor when you change your opti?
Are my symptoms caused only for a failing cap or maybe the hole part is dying?
There is $300 difference between both decisions.....
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