LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Instantaneous Optispark Failure?

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Old Jun 19, 2019 | 07:56 PM
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Default Instantaneous Optispark Failure?

After a hard day of driving at the track ended up having to let my buddy borrow my trailer. So my LT1 was street driven home through a TORRENTIALdownpour. Right towards the end the car died on the road and wouldn't start back up. No barely running, no nothing at all.

Scanned it after finally getting it home and it read a Code 16. Now this indicates opti failure OR the harness.

As i understand it, when the opti signal fails it typically does it gradually, not instantly. This was an instant failure. Like flipping a light switch.

Also, with a cold air intake and tons of rain, is it a possibility that the intake vent for the opti sucked rain into the sensor causing the failure???

I have a spline drive unit that is converted to a vented. Everything is sealed using silicone. Only places water could have entered are maybe the harness connector at the opti or the vent.
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Old Jun 20, 2019 | 02:05 PM
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Opti is most likely wet. Only way to tell is to take it off and take the cover off. This is a notorious issue whether it be heavy rain or washing out the engine bay. Contrary to popular belief it doesn't mean it's bad once it gets wet. You can dry it out and most likely it will be fine.
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Old Jun 20, 2019 | 09:21 PM
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well looks like its time for a torque head kit
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Old Jun 21, 2019 | 01:45 AM
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Originally Posted by hbomb2k
well looks like its time for a torque head kit
Giving up on the optispark that easy?
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Old Jun 21, 2019 | 10:43 AM
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OP

you can spend huge $ on TH...or just clean/dry out the Opti. Driving in the rain conditions you were in normally "should" be OK but as noted can affect Opti in those heavy rain conditions especially where the Opti can get submerged in flooded streets if that was your situation.

Assuming water contamination was the "why"....you should also check the function of the vent harness as it may now be clogged
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Old Jun 22, 2019 | 12:57 PM
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Yeah TH is actually a little bit of a knee jerk reaction. The opti has been fine to me. Is it really possible that simply tearing it down cleaning and drying it could fix it?!
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Old Jun 22, 2019 | 03:10 PM
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Try pulling the harness connector and blow it out with air. Possible that water dripped in there and caused a short.
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Old Jun 23, 2019 | 02:32 PM
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Originally Posted by ******
OP

you can spend huge $ on TH...or just clean/dry out the Opti. Driving in the rain conditions you were in normally "should" be OK but as noted can affect Opti in those heavy rain conditions especially where the Opti can get submerged in flooded streets if that was your situation.

Assuming water contamination was the "why"....you should also check the function of the vent harness as it may now be clogged

Tore it down, made sure everything was super clean, reassembled and still same exact issue. :/ i think the water fully killed the sensor.

Now I have another question. I want to go to a 95-97 pin drive setup for my replacement so that I can run a double row timing set. With a 94 year motor I know I will need to change out the dowel pin and the front cover. But I have also conflicting answers on if I will need to machine the cam or not.

Will i need to machine the cam snout or not, because if so it seems a cam swap is in order.
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