LT1 Cap and Rotor, clean and rebuild the opti

As some of you may know I'm cleaning up leaks and other issues on my 95 Parisienne Safari. I've come to the point where the water pump is off the engine, along with the harmonic balancer. other than a lot of oil grime and all over the distributor there doesn't seem to be any external damage to it. I removed the three 10mm bolts holding the distributor to the timming chain cover and pulled the distributor off the engine. I discover that the seal to the distributor has failed, it's in two parts, the metal ring is still in place on the timing chain cover but the rubber seal is just floating about in the oil as it flowed out the back of the distributor, just inside the timing chain cover. this would be my biggest and the major cause of my oil leaks it just wasn't sealing. Not to mention that the two o rings that should be on the distributor's shaft were nowhere to be found....

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Ok so some call the distributor an opti, took me a while to find out that the opti is just an optical sensor inside the distributor that reads a metal foil disc that spins with the cam. Both the optical sensor and the metal foil disc almost never go bad, so the assumption I was told, is that if the car runs, then optical sensor is fine, so leave it alone. what can and often does go bad is are the caps and rotors and they can both be changed independent of the opti sensor, and at a third the cost of a complete opti spark unit. I opted to buy a cap and rotor kit in the States from autozone just north of detroit on gratiot ave at 21 mile rd. the manager there is a b body guy and hosts a car cruise at this location every july the same week end we have our wagonfest in NY. the kit contains distructions, a new cap, new rotor, new screws, and O rings.

the cap is held on to the distributor with small torque screws, you will need a small E4 extention socket to remove all four screws. you will also need a small torque screw driver to removed the two screws that hold the rotor to the distributor's shaft, I think it's a T10 but then mine was worn and hard to read the actual size i was using, but it was small.

When I pulled my distributor apart I found that a fair amount of engine oil had worked it way into the distributor cap, and the chamber where the optical sensor is. It's never good to have liquids inside the distributor. there was also some carbon build up on the rotor itself and the electrodes. so along with the oil some moisture must have been getting in but the wagon still ran, I had a bad miss fire and surges, so this combined with the leaks in the intake would account for a lot of my rough running issues.

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I cleaned up the oil from the optical sensor and the distributor's base plate then intalled the new parts

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and the new o rings on the distributor's shaft

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now it's ready to go back on the wagon

Looks like what most of my optis I rebuilt looked like

It's amazing it still ran...

I bet it's going to run fantastic now. I really want to do the Opti and fuel pump on my '96...both are original and on borrowed time!

Keep the updates coming. Great work Pat!!

-Mike

I think rebuilt might be a strong word to use here,.does a new cap and rotor kit qualify as a rebuilt?

If so,. i have rebuilt lots of distributors over the years,...

If it`s not back on the wagon yet, put a but of red loctite on the rotor screws, and a little bead of permatex #2 or ultra black around the lip of the case.

When I did the one on the caprice last month, the opti o-rings were MIA as well.

I notice that the electrodes on your distributor cap are not brass. I just received an AC Delco from Rock Auto that also doesn't have brass electrodes. Is that it a big deal?

Thanks,

rjathon wrote:

I notice that the electrodes on your distributor cap are not brass. I just received an AC Delco from Rock Auto that also doesn't have brass electrodes. Is that it a big deal?

Thanks,

I would say that it's not a big deal, my wagon has never ran better since I've owned it, and the electrodes on my original cap weren't brass either, just dirty

LT1 caps and rotors off ebay are dirt cheap. Good work.