URGENT: How to disassemble rest od distributor ?

[prebordao]

I'm looking for cleaning and lubeing the advance on my dist, but can't figure how to remove the plate below the points... The pic below shows where I'm stuck...
Help guys...

[brads911sc]

There is a thread on how to do this. There may be others. Enjoy.

Distributor service (Clean and lube) real easy without removing the pinion gear!

[Gunter]

Remove the small felt plug inside the shaft and save it.
DO NOT open the screw under the felt.
Remove the black rubber plug that connects the points.
The plug should just pop out.
Turn the trigger plate a little and see if you can find small fasteners under the trigger plate that hold the assembly to the distributor body.

[prebordao]

I'm looking for the fasteners but there's no condenser

[Gunter]

You're right, my mistake.
The plug is the connection for the points.
The whole top assembly is either held to the body by fasteners under the trigger plate or fasteners on the outside.

It's been years that I did one of these with Kettering. (Points and condenser) but yours is CDI. (Points but no condenser)

[prebordao]

Made it !
removed 2 external screws and pried the plate out

[Gunter]

You can submerge the whole thing into Kerosene, Diesel or? to clean everything including the 3 small holes on the bottom.
Check/clean the inside weights and springs and make sure that the center-bearing for the trigger plate moves freely. Important!
Use penetrating oil if necessary to free the bearing!
Notice that the top half of the distributor shaft is moved by the weights. That's the mechanical centrifugal advance. Squirt light oil into the top and turn it repeatedly to work the oil in.

Lube the weights and springs.

When you put it back together, the small ball on the trigger plate needs a dab of grease so the vacuum advance works correctly.
Check the vac pod by using a short hose, suck on it and watch the trigger plate: It should move and hold vacuum when you sue the tip of your tongue to seal the hose.

[prebordao]

Well, it was a lot better than I expected. Everything (weights, springs) was reasonably clean and moving freely. I guess that when the engine had a major rebuild 4 years ago, they probably opened the dist too.
I oiled everything a bit and took more care of the vacuum plate which was a bit stiff, so I put some grease underneath it and on the small ball.
After I got everything together, I tried sucking on the vacuum hose but couldn't made the plate move. Either weak lungs or the pod is shot ! However, with engine running, if I remove and plug the hose, the revs go up.

Put the distributor back on, went for a drive and the 1.5-2K stumbling kept on. I wasn't really expecting anything different as the dizzy seemed all ok...
So, again, it must be fuel related....

[Gunter]

Originally Posted by prebordao

Well, it was a lot better than I expected. Everything (weights, springs) was reasonably clean and moving freely. I guess that when the engine had a major rebuild 4 years ago, they probably opened the dist too.
I oiled everything a bit and took more care of the vacuum plate which was a bit stiff, so I put some grease underneath it and on the small ball.
After I got everything together, I tried sucking on the vacuum hose but couldn't made the plate move. Either weak lungs or the pod is shot ! However, with engine running, if I remove and plug the hose, the revs go up.

? Revs go up? Is the vacuum on a '74 retard? Not advance?

Put the distributor back on, went for a drive and the 1.5-2K stumbling kept on. I wasn't really expecting anything different as the dizzy seemed all ok...
So, again, it must be fuel related....

How exactly do you set timing?
Is it a stock CIS?
Try setting the timing per factory but leave the vacuum disconnected and plugged to see if the stumble goes away.
How do you adjust mixture?
Do you know how to set it "by ear" without a gas-analyzer?

[prebordao]

Well, before removing the dizzy, i've scratched some notches everywhere so as not to mess with the timing, without having to redo-it. Sure enough, when I tested it after, it felt the same.

It's a stock CIS and timing was set recently by a shop while trying to cure the stumbling. I'm assuming they did it by factory specs.
I tried leaving the vac disconnected and plugged but it didn't do any change. The guys at the shop are leaning to a bad FD as an explanation.
I find it a bit weird as it started suddenly (over lunch).

There's more detail in another thread (severe stumbling above 2000rpm ?) but the symptoms are:

- idle wavers periodically (that is drops and then resumes every 5-7 sec or so)
- when accelerating there's an hesitation / stutttering arolund 1.5-2K. It's a "transition" thing: if you throttle it very slowly it won't happen, but do it at the usual rhythm and it stutters breefly and then resumes normally.
- at higher revs (>2.5K) everything's ok: no stuttering, pulls strongly

[Gunter]

Is the vacuum retard or advance on a '74?
Has the shop given you figures for system pressure?
And control pressures cold and warm?

I'd get myself a Stroboscope (Timing Light) and learn how to set timing.
I'd learn how to adjust mixture "by ear". It's not that hard, do a search here.
I'd search for: "Hunting at idle".
I'd open the top line on the WUR and make sure the tiny screen is clean.

If the fuel distributor is suspect, I'd pull the injectors out and place them into 6 equal-size glass jars, then ignition ON and lift the Air Sensor Plate inside the airbox for 2-3 seconds to see that there is equal flow/volume in the jars. Spray pattern for each injector can be checked the same way.

It's very difficult for us to know what the shop is doing to solve the problem.

[prebordao]

Vacuum advance or retard ? I don't really know, but the line goes to the front of the TB (so a nipple pointing to car rear).

[Gunter]

Sounds like vacuum retard.

Learn more about how to work on your car because we don't know what the shop does to find the problem.
What are the CIS pressures? System? Control cold and warm?
Can you do the 6 glass jar check for volume and spray?

Any suggestions coming from the board usually work only if the person asking for help can go through the steps and report back.

[RoninLB]

all US CIS up to 1976 had vacuum retard of about 5 degrees [as per Workshop Manual]. Many US CIS 1977 had vacuum canister line plugged from the factory except California.


1] If the vacuum line is left plugged and initial timing of 5 degrees advance / BTDC total should be at 35 degrees. If not adjust total timing to 35 degrees and let initial fall where it may.

2] my stock 2.5 CO was raised to 3.5

3] and factory suggested spark plugs were to cold for the street. One step hotter kept the engine smooth



helped me when everything was factory stock

[Gunter]

Thanks, Ron.

Sounds like he doesn't work/adjust things on the engine himself and that makes it difficult to know what the shop did or wants to do.

[prebordao]

Guys, I don't have a workshop of my own and live in an apartment building, so only very limited work is within my reach.

Since, around here, the availability of 911 experienced shops is quite scarce, what I'm trying to do with my posts, is to get "clues" that I can pass along to the mechanic at the shop, so that he has a better chance of getting "unstuck". This, as "politely" as possible, as most of them have themselves in the highest regard ! Not easy sometimes...

That's why, I have trouble passing back some of the info that the helpful crowd around here asks of me.