Distributor Maintenance

[beatnavy]

In the spirit of "what can I futz with next?" I'm looking to do work on my distributor. When I start the car up I often hear a squeaking at idle. I think I've read that this indicates a need to lube the distributor shaft. I've got the grease and the O-ring. I'd also like to check function of vacuum advance and generally clean the injection points and other bits while I'm in there. I can also properly install the condenser that I couldn't do with the distributor in.

Does anyone have or know of a good step-by-step post on this or another forum for distributor removal and maintenance?

Thanks --

rc

[porschetub]

Originally Posted by beatnavy

In the spirit of "what can I futz with next?" I'm looking to do work on my distributor. When I start the car up I often hear a squeaking at idle. I think I've read that this indicates a need to lube the distributor shaft. I've got the grease and the O-ring. I'd also like to check function of vacuum advance and generally clean the injection points and other bits while I'm in there. I can also properly install the condenser that I couldn't do with the distributor in.

Does anyone have or know of a good step-by-step post on this or another forum for distributor removal and maintenance?

Thanks --

rc

Set the unit to TDC @ #1 cylinder ,remove from motor and suck with your mouth on the the vacuum lines and check the points plate is moving freely with the cap off,its the advance side that is most important,retard side is less important and often unplugged and plugged on the plenum manifold.
Fit a multimeter to the efi contact points and check for continuity as they open and close,if that test is ok you are fine,if not the points contact block may be getting worn or if you have bad running they may be worn out already.
You can remove the efi points assembly and check the actual contact points for wear also.
Next check your ignition points and rotor ,cheap to buy and best to replace if suspect or look @ Pertronics for a longterm solution.
You can remove all consumable parts and clean the whole assembly in solvent to clean and free up the advance assembly if chocked up with cr#p but make sure you remove or replace the oil seal for that seals it into the engine.
Any work past this is best preformed by a Bosch repair shop or good specialist in this area.

[beatnavy]

Thanks, but I had some time last night (Mother's Day, what else should one do but work on the car?) and went ahead and pulled out the dizzy. I used this thread on 914World (914World.com - The fastest growing online 914 community!) running over the weekend as a bit of a guide for taking apart and cleaning the insides. Mine was pretty dirty, and I was having some similar symptoms as the person on that thread (e.g., car often idles very well but at other times, especially when warm, will idle high). I have two follow up questions for anyone that's game:

1. I cleaned and lubed the advance plates, and they seem to move more freely now. The actual arm from the vacuum unit seems to require a fair amount of force to move -- I struggle to think a light vacuum from manifold will move that, but maybe I'm not thinking of this right. Is there a good way to confirm vacuum unit is serviceable (e.g., use the "suck" test described above)?

2. Reinstalling the dizzy -- I have not removed the gear. Shouldn't the dizzy generally pop down and "lock" with the two offset "teeth?" I'm struggling a bit to confirm that I have it seated properly. It may be that the hold down plate is cockeyed and keeping me from seating the dizzy all the way down. I assume a good check when you've got it seated in there properly is the rotor won't spin freely, correct?

Thanks for the info and help!

[luskesq]

It should be seated (although not necessarily in the right slot--rotor points to where it was prior to removal, right?) if you can spin the rotor by hand. Best way to confirm vacuum on the cannister is to use a vacuum pump. I've used my for the cannister, mps and other things. You can pick one up at HF for under $20. Remember to take a coupon.

Keith

[beatnavy]

I'm still struggling mightily to get the distributor seated correctly into the slot. I did not take the gear drive out. I can see down in the hole the two slots that align with the two teeth on the dizzy shaft. I also see what is the spring loaded piece in the center. As far as I can tell there's nothing blocking anything. Is this simply a matter of 100% no-kidding-have-to-line-it-up-and-hit-it-right-on to get it to go? I would think by rotating the unit and pushing down I would get it to seat.

Am I missing something?

[Dave at Pelican Parts]

Nope, that should do it. You may need to wiggle the rotor around to get the drive lugs lined up correctly, but that's about all. I do find that I often need to twist the distributor body and push down in order for it to seat all the way. And the clamp around the mounting hole has to be loose, of course.

Note that the rotor will rotate some against the spring pressure for the centrifugal advance if you try to move it by hand. It should snap back to its neutral position, though.

--DD

[beatnavy]

Thanks Dave. I knew you'd arrive in the nick of time! For those keeping score at home, it turns out the new O-ring I installed either wasn't seated properly or isn't the right size. I tried it without the clamp and O-ring, and it went in fine. I tried it with the old O-ring, and it went in fine. I'm still not sure why the new O-ring was the issue, but for now I'm running with the old one. I hope all this was worth the effort! Now I just need to reset the dwell and timing. Oh, and figure out where that loose ground is that's now giving me hot start problems.

That's the problem with these 914's: you just so quickly run out of things to work on....

[porschetub]

The o-ring commomly supplied is almost always wrong ,i have found you can't even get the dizzy back in with some of them and if you can they are damaged when you remove it again...wrong shape perhaps?

[beatnavy]

Hi porschetub, that's interesting. It's not in front of me right now, but I do recall the shape of the new O-ring that was causing me problems looked to be slightly elongated in the center (like it crowned just a bit around it's "equator") whereas the old one was perfectly square along the edge. Maybe it would have worked with more force, but I was reluctant to do that. I wonder if anyone else is having trouble with them.

[porschetub]

Originally Posted by beatnavy

Hi porschetub, that's interesting. It's not in front of me right now, but I do recall the shape of the new O-ring that was causing me problems looked to be slightly elongated in the center (like it crowned just a bit around it's "equator") whereas the old one was perfectly square along the edge. Maybe it would have worked with more force, but I was reluctant to do that. I wonder if anyone else is having trouble with them.

Yes correct "crowned" is a good description ,there in lies the problem,this crowned area normal sticks up and will rip slightly even with lube on it,I rebuilt dizzies for a while and never found these seals much good,the original is square as you say and the replacement one is a " D" section.
Your nearest dealer may have the genuine part if you are worried about the old one.

[TheCabinetmaker]

might as well clean and adjust the trigger points if you have a D-jet dizzie. worn lifter on trigger points will cause bouncing points which will lead to rich running,