I was replacing the ignition rotor on my 82 Z28 (not original motor, said to be a rebuilt '79 350) and noticed, what seems to me, an abnormality, with the car not me :P.
To the best of my memory, any time in the past when I have changed a rotor, as I tighten the screws the rotor would rotate as the distributor shaft stayed in place and "snap" back in place when I would relieve pressure on the screw. This time there is a noticeable difference in the force needed to turn the rotor and it doesn't "snap" back in place, for lack of a better way to put it, it drifts back most of the way then stops just short of "place". Is it me or is this drift not right? I put heavier advance springs on as a test and had little effect. Everything moves smoothly just seems like the shaft is moving in a tight bushing or weighted or...

Is this normal?

Has this happened to anyone else?

How to fix? If there really is something wrong.

Is it just me? Car runs fine. Don't worry about it?

Looking forward to your input.

 

Sounds like the bottom of the rotor is rubbing on the advance weights.

Very common performance malfunction; this will make a car have the multiple idle-speed problem, spark knock from hell, etc. etc. If that's what it is, it's the rotor; either put a washer under the screw hole bosses, or shave off the little ribs or whatever the particular rotor has on its bottom side.

 

Even with the rotor off it doesn't snap back into place. I should have said the lack of snap is the same with the rotor on/rotor off, small springs/large springs/no springs, weights on/weights off.

 

In that case, it's probably just the rotating piece (that the reluctor and rotor attach to) needing to be removed, and the surface where it meets the main shaft cleaned and lubed.

 

This will be new territory for me.

Do I need to remove the distributor from the engine to do this?

Any special cleaners and lubes?

Any tips or tricks to minimize problems?

 

I tride once and failed at rebuilding a distributor. I ended up needeing presses, pullers and such that I didn't have. Now I just replace them.

Still if you want to try it first get all the electrical out. Mark your position well I would actually try scratching it in where the rotor was pointing to the edge of the base.

Then a good rinse with carb, parts, or break cleaner then a soak in kerosene while moving the sticky parts by hand untill they free up. Then again rinse with break, parts, or carb cleaner.
If they don't free up after being cleaned you have to fully dissasemble and loosen up what ever is to tight.
As far as lubricant goes I use dielectric grease up top and motor oil in the shaft.

 

The main problem with getting at the "sticky" area where the advance plate rotates around the main shaft is getting the distributor shaft pulled out. It's usually got a couple decades of schmutz built up and it doesn't want to pull out more than few inches before it hangs up and starts ripping the seals all the heck. Fortunately, you don't have to pull it all the way out. Just get it up a few inches and then slide the advance plate DOWN those few inches on the main shaft and you can get to the "gunked up" area just fine. Little carb cleaner, a tooth brush and a few drops of fresh motor oil later and it's ready to be reassembled and dropped back in.

 

Ok. You won't feel a thing. Just count backwards from 100 Ms. Z28.

Nurse, mark distributor position.
Wrench.
Nice and easy. No worries.

OH @#$) SUCTION!!

CODE RED! I REPEAT, CODE RED!

Ok, everybody calm down. We're back in business.

Whew! That was a close call. Good work team.

Operation a sucess.

Thanks.

 

Heh heh. Good job, doctor.