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Friends:
Been reading too much. Optispark was replaced on 96 SS at 100K, by GM dealer recently (decoded to be Cardone part). 2K miles it failed intermittently when engine warms up. Indicating Code P0372 (high res signal A too few pulses). Removed and opened up. Absolutely spotless, except the speed rpm disc is warped and indication of disc serious rubbing the sensor housing on part of it's arc of rotation. Also the sensor housing house a l slight taper to one side, increasing the likelyhood of the rub. Question, I've read WAY too much. I ordered an AC/Delco from Rock Auto, believing it to be a better replacement for the defective Cardone. Now I am hearing and reading that the AC/Delco may actually be a Cardone manuf part? Have not received yet, but now getting concerned they more expensive OEM may not be any better?

Waiting to see the part number that actually shows up, and contemplating sending back for something else?

Oh yeah, the GM dealer replacement was done for the previous owner (a friend) so the dealer has accepted no responsibility warranty wise.
Thanks in advance for all you Jedi's
 

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Your best bet is to get lucky and find an OEM one and get the Mistu optical sensor outa it. Then but a cap and rotor and try to build one good one outa the parts you can get your hands on.

May be buy a cheap one at Rockauto, and put an OEM Mistu sensor in it ?

It's a 100k part so they need replacement once and a while....
This may help Rebuild Opti - New Parts In Old Distributor
Good Luck.
-ALF out....
 

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If the harness was not changed, look at this link. post #96


If it was "never mind"
 

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Poor quality parts
coupled with poor quality manufacture
coupled with poor quality assembly
coupled with absent quality control
and likely zero test and checkout all sum up to a terrible few years as aftermarket got into the repop bizz with optis as oem became NLA and our cars started hitting replacement mileage. The issues seem to have settled on:
poor fitting housing to cap,
thermo overload of the sensor in hot operating conditions,
missing or incorrectly seated housing gasket(s),
slotted disc loose screw(s),
blocked vent harness in conjunction with poor quality thin caps deflecting and getting sucked in shredding themselves, and the rotor,
poor quality and breaking 'plastic welded' tabs holding the rotor,

Organ harvesting of the oem unit for the sensor is pretty common in a JY, but savvy guys have learned to keep the one out of theirs (and even the cast housing if the bearing is in good shape and just get a good quality cap and rotor and then 'blueprint' the whole dam thing. There's several threads on that.
 
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I purchased an AC/Delco optispark from Rockauto last summer and I haven’t had any problems with it, they are rebuilt GM optisparks, when you receive your opti you can send yours in for core I believe they give you $75. I don’t know if it had the Mitsubishi sensor cuz I didn’t open it, my mechanic did, to put some loctite thread locker on the optical disc screw.

Be that you as well put loctite thread locker that as well they are known to get loose.
 

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One of the frequent flaws in the aftermarket is the "platter" incorrectly clocked to it's drive that terminates at the cam's pin drive.
 
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One of the frequent flaws in the aftermarket is the "platter" incorrectly clocked to it's drive that terminates at the cam's pin drive.
Oo yah thx. I was holding that one to last but forgot it. It was one of the later wrinkles uncovered in the ' Bad AM Opti' story. Even finding the 'perfect matching' bearing without requiring a shim was at least at one time an issue. Urban legend was that 1/2 to 1 1/2 degrees had roughly been measured off, but that the ecm could adjust timing for up to that much???? Any basis for that, or just total hare-brained guess and BS?????
 

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Urban legend was that 1/2 to 1 1/2 degrees had roughly been measured off, but that the ecm could adjust timing for up to that much???? Any basis for that, or just total hare-brained guess and BS?????
The PCM can adjust timing. The real question is does it re calibrate the injection timing in any way? The PCM may have no way of knowing or correcting a out of range OPTI. Injector timing is very important.

I have wondered about adjusting TDC with the PCM ever since reading this thread:

Injector TIMING :)

One of the frequent flaws in the aftermarket is the "platter" incorrectly clocked to it's drive that terminates at the cam's pin drive.
Very few of us put timing pointers on LT1s
I have read on this forum about the "incorrectly clocked platter" All I could think of to check this was to mark the optical sensor then use the high resolution slots to mark the middle of the #2 cylinder(widest low res slot) then compare the aligned marks to the actual TDC of cylinder #2.. Would this work? Is there a better way?
 

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I purchased an AC/Delco optispark from Rockauto last summer and I haven’t had any problems with it, they are rebuilt GM optisparks, when you receive your opti you can send yours in for core I believe they give you $75. I don’t know if it had the Mitsubishi sensor cuz I didn’t open it, my mechanic did, to put some loctite thread locker on the optical disc screw.

Be that you as well put loctite thread locker that as well they are known to get loose.
I purchased an AC/Delco optispark from Rockauto last summer and I haven’t had any problems with it, they are rebuilt GM optisparks, when you receive your opti you can send yours in for core I believe they give you $75. I don’t know if it had the Mitsubishi sensor cuz I didn’t open it, my mechanic did, to put some loctite thread locker on the optical disc screw.

Be that you as well put loctite thread locker that as well they are known to get loose.
Do you happen to have the part number for the optispark that you purchased from Rockauto? I don't see an AC Delco option on there.

Thanks
 
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