1993z28camaro

It started when I drove my 93 LT1 through water that was high enough it probably got the opti wet. When i started it the next day it ran rough. It started right away but ideal was spotty idealing around 1500 to 800 rpms when it usually ideals around 800. It backfired and didn't want to accelerate. It aslo threw the SES light but i wasn't able to get the codes. The light comes on periodically and doesn't stay on when the car it turned off and restarted.

So today I decided I needed to test the opti before I tear it down. I have 11V at the ICM at terminals A and D and had 2V at terminal B. I have spark at the plugs but the test light doesn't light up when terminals C and B are bridged.

Any thoughts or suggestions on where to go from here or what to test? I appreciate all the help I can get.

The Untouchable

your opti may just have some water in the cap,

1993z28camaro

I guess I assumed that if water was in the cap the opti would fail. I've haven't heard of water being in the opti without failure. But then again, you know what they say about assuming.

94ltz

I guess if you want to try you could go at this in a couple directions such as-

1- pull the cap off the opti and see if there is in fact water in there and if so let it dry out, clean it up and put it back together and try that

2- Switch out the cap and rotor also while cleaning up the contacts

3- Replace the opti and hope all is gone

Either way it's going to take some time, but i have seen a cap and rotor help a what was thought to be a failing opti.

Injuneer

If the SES light comes on, the code is stored in the ECM, even if the light goes off, you turn the key off, you restart the engine, etc. Its stored and you can recall it. With your 93, you can flash the codes on the SES light by shorting the ALDL connector pins. A faulty optical sensor, even one with intermittent problems, will set DTC 16 and 36.

Erratic idle can be caused by faulty optical sensor signals. Did you check the Opti harness connectors for water, corrosion or damaged pins. Rough idle and missing can be caused by water in the cap, water in the plug wire towers, corroded wires, damp wires with poor insulation, etc. You need to inspect all the plug wires and the coil wires, including the ends pushed into the Opti towers.

camaroz28383

when optis get wet they don't always fail immediately some times a week or two down the road it will just take a dump the cap and rotor portion will handle water its the optical sensor that dies in most cases, which sometimes dies a slow death