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I did some brief forensics on the old opti. It was a GM opti that had the Mitsubishi optics. The internals that I saw were slightly corroded and oil had gotten inside from a leak around the casing. I couldn't fully disassemble it so not sure what the optics looks like. The rotor and contacts were only slightly corroded. Overall, it didn't look too bad. I wish I could rebuild this to keep as a spare.
I would suggest you at least hang onto the Mitsubishi sensor. It may be roached, but the fault also could have simply been corrosion closing up the slots in the wheel, and/or contaminants (oil film, etc) on the optics of the sensor. Unfortunately, most likely the only way you could truly test it would be to run it again after cleaning everything up and installing it into a good distributor, and taking your chances that it'd be okay. Not a bet I'd care to make, given the difficulty of accessing the unit. But, with the apparent lack of reliable off-brand sensors, that Mitsu might still hold some value.
could have simply been contaminants (oil film, etc) on the optics of the sensor.
Unfortunately, most likely the only way you could truly test it would be to run it again after cleaning everything up and installing it into a good distributor,
I bet the lenses got dirty.
You could clean it and test it this way: run kleenex w/brake cleaner on it, through the sensor a few times until the kleenex come through clean...then repeat w/windex.
To test, Unplug your opti harness from your new opti, plug into your old/cleaned one with the old opti just laying on top of the motor, or where ever is convenient (not installed). Un plug your injector harness(s), then your fuel pump relay. This will disable things you don't need "running".
Now, take your old opti drive pin, and chuck it up in a drill, insert into opti, turn ignition ON, and start the drill. Set the drill to run by itself and leave it for a while; 10 minutes? 20 minutes?
With the key ON, drill spinning the opti, and the opti plugged into the opti harness...the ECM totally "thinks" that the engine is running. If the sensor/opti is going to have issues, it will throw another H16 or something. You can also monitor your tach while the drill is running; should read a steady RPM (what ever RPM the drill is spinning, x2).
I just picked up an AIP unit from Sac City last week. My current Opti is still working at 126k and has a new cap and rotor. I bought the new unit as more of a scarecrow and to have one on-hand, due to mileage.
The unit does appear well-built. I was going to do a forensic on it and see if the rotor had metal or plastic rivets. According to Sac City, the manufacturer says the seal is fine and seals well (no RTV needed) and the rotor screws are red lock-tited from the factory. I'll be curious to see..........
First let me say thanks to everyone who offered such great comments and ideas, during this repair. Everything is back together and it is running very well. No codes were generated.
I am still waiting on some spark plug wire retainers and that will put the finishing touches on the job. I ran a drain tube from the water pump bearing weep hole.
Here's the final product.
Thanks for all the posts and info. guys. I just bought a 1992 LS1. It only has 28kmi on it and it looks very clean. I was able to start to get familiar with this whole "Opti" issue. I don't see any leaks around mine, but at age 25, I suppose an issue could pop up anytime. The coolant temp does creep up a little if it's at a standstill on a hot day with the A/C running. I'm going to replace the radiator and I now know of all the other things I should do while I'm in the there! Thanks.
Thanks for all the posts and info. guys. I just bought a 1992 LS1. It only has 28kmi on it and it looks very clean. I was able to start to get familiar with this whole "Opti" issue. I don't see any leaks around mine, but at age 25, I suppose an issue could pop up anytime. The coolant temp does creep up a little if it's at a standstill on a hot day with the A/C running. I'm going to replace the radiator and I now know of all the other things I should do while I'm in the there! Thanks.
There's a reasonable chance that your car still has the original distributor in it, given the low mileage on the odometer. If that's the case, you might be better off leaving it alone. There's a pile of anecdotal evidence that suggests that the Mitsubishi sensors that were used in the OEM units and are no longer manufactured, are more durable than the off-brand sensors that are currently available. If it were my car, I'd run it until the distributor dies, then hope I could find a good replacement.
Regarding engine cooling, one of the design weaknesses of these cars is that they are bottom-feeders, and will suck an astonishing assortment of garbage into the cooling stack, thus blocking the airflow. Consider adding a debris screen to cut down on the amount of stuff that will build up in there, after you've cleaned out whatever's in there now:
There's a reasonable chance that your car still has the original distributor in it, given the low mileage on the odometer. If that's the case, you might be better off leaving it alone. There's a pile of anecdotal evidence that suggests that the Mitsubishi sensors that were used in the OEM units and are no longer manufactured, are more durable than the off-brand sensors that are currently available. If it were my car, I'd run it until the distributor dies, then hope I could find a good replacement.
Regarding engine cooling, one of the design weaknesses of these cars is that they are bottom-feeders, and will suck an astonishing assortment of garbage into the cooling stack, thus blocking the airflow. Consider adding a debris screen to cut down on the amount of stuff that will build up in there, after you've cleaned out whatever's in there now:
Live well,
SJW
SJU - Thanks, I'll look for contaminants. Maybe I'll just do the cap, rotor, and plugs/wires while I'm in doing the radiator. Not sure what to do about the water pump. I really only want to have to tear into the front of this thing once! Thanks for the info.
08-23-2017, 09:28 PM
I bet the lenses got dirty.
