Delco distributor rebuild kit???

[Surcouf]

Good afternoon,

After having to destroy my late model distributor casing to take it out, I would like to study the possibility to rebuild it. Issue is I damaged a couple parts in the process: the nylon washer among them.

MM does not sell those ones. Ken who used to rebuild those distributor has a very small stock of parts that he uses exclusively for the MM overhauls, he does not know where I could find those.

does anybody else has any idea where I would be able to find the internal parts for such a rebuild? Was that model of distributor be installed on any old US car?

Alternative is of course to go for a new distributor... but I like to repair thing (not always a good idea, as my block is trying to explain me...)
Thank you !

[Sam]

Well, not sure where I got this knowledge from but I remember being told that the late model A4 Delco distributor was used on a 1974 Chevy Vega?? I know that may not be too beneficial [the car certainly was not] but it is better than an early model A4 which uses a Prestolite distributor from a 1944 Willy's Jeep. [My memory has now been restored and the info came from a compilation of various A4 parts from an Alberg 30 users' web site]. Good luck

[ronstory]

The cap and rotor are the same as 1974 vega and some of the internal guts as well. But the A4 is mechanical only advance and is supposed to be 'all-in' at 1700rpm. That advance curve is dependent on the weights and springs for AR design and are very different profile than the Chevy. However, the plastic bushing bits I'm sure would be 'darn close'.

You could find a A4 specific distributor, and for reference I got my last one for $150 from ebay with the pertronix module. MMI sells them as well.

[ronstory]

This is even in the NE. Offer a $100 and see what happens.

https://www.ebay.com/itm/Universal-Atomic-4-Distributor-Assembly/193315314534?hash=item2d027d9b66:g:kPIAAOSwERFeK6uL

[Surcouf]

This is even in the NE. Offer a $100 and see what happens.

https://www.ebay.com/itm/Universal-A...IAAOSwERFeK6uL

LOL... I made an offer at 4PM on that one. We finally had a deal at 99$ later tonight
It is a good compromise for what I am trying to do, rather than just buying a brand new distributor at MM.

As a remark.... I doubt that many in Jersey City would be hard core fans of the Patriots, so not sure I would consider that to be in New England

[ronstory]

Woo-hoo!

I'm glad it worked out and my comment on 'NE' was meant to be "North East".

That that trouble about about abbreviations, too many options for an answer. ;^)

[Surcouf]

Ignition time test failure

Hello,

one question for you guys: I cannot reproduce the final timing tuning as demonstrated by Don M in his video - it is the one where it performs the "continuity test". As a reminder:
- I had to destroy the distributor housing to remove it, completely seized.
- Purchased a used one on baybay, removed its mechanical points + condenser, and install a few of my internals (plate + electronic points).
- I set-up the engine at TDC as per Don's video, install new distributor axis and casing to have them aligned perpendicular to the engine.
- I started the engine. Still pretty rough, does not idle well at all, but it runs, and allows me to heat block several times to verify head torque etc..;

I have a long list of things to verify in order to have a better running engine: verify spark plug seat are not full of paint, use my carburator kit for its purpose (I had decided to keep the carburetor as-is until first re-start, not to mess up too many things at the same time), etc...

And on my to-do list, was the last ignition timing test as per Don's video. But, I just cannot get the ignitor module to produce anything. let me explain:
- I first started without voltage, just testing resistance across the module. I got 2.6 kohm on the one that was in the engine, 16 kohm on a spare one left by the PO
- I tried to install each of them in the distributor and move distributor body, these resistance values never changed.
- I did the same thing with both module disassembled from distributor, moving the magnetic ring in front of them, but resistance stays constant
- So assuming that some voltage was required for the module to act properly, I connected the module in series with a 12V lamp to the battery, and cannot get the lamp to switch on (I have verified that it would if connected directly to the battery

As I was able to start the engine, and have it run (not great, but runs), I have to assume that this module or the magnetic ring can't be fully dead.

So my questions: am I doing wrong something wrong? Are both of these modules dead? What should be the resistance across a good module?

Thank you

[ronstory]

First you need to spin the engine to TDC on #1 cylinder. Loosen the disti clamp so you can rotate the distributor housing, but mark it's original position first... just in case.

The rotor will be stationary in this exercise and should be pointing to away from the cylinder head. Rotate the disti so the rotor is positioned between Cylinder #1 and #3 on the cap.

Turn on the ignition and clip a volt meter to minus terminal of the coil and it should read 12V ish. Rotate the disti CCW until the meter reads ground. The moment that the voltage drops is when the coil should fire on #1 cylinder.

Not sure about the continuity test on an IE, but Don's approach works great on mechanical points.

[Don Moyer]

Ignitor timing

Surcouf; I can't follow your ohms checks completely, but the fact that your engine runs at all would seem to confirm that your Ignitor module is opening and closing properly. The fact that the engine is running poorly suggests that the opening and closing of the Ignitor is not occurring at the proper time.

Ronstory's suggestions are right on, but before starting all over again to set the timing, you might try a quick fix by simply rotating the distributor a small amount in each direction looking for a spot where the engine runs better - even at idle. Then when you have an opportunity, you can power time the engine following the Universal instructions in the attachment. Don

[Surcouf]

Surcouf; I can't follow your ohms checks completely, but the fact that your engine runs at all would seem to confirm that your Ignitor module is opening and closing properly. The fact that the engine is running poorly suggests that the opening and closing of the Ignitor is not occurring at the proper time.

Ronstory's suggestions are right on, but before starting all over again to set the timing, you might try a quick fix by simply rotating the distributor a small amount in each direction looking for a spot where the engine runs better - even at idle. Then when you have an opportunity, you can power time the engine following the Universal instructions in the attachment. Don

Thank you very much Don for your answer. I have tried to follow your advice (very well explained in your video - rpiceless). But my idle is so rough for you, that I could not "feel" much improvement by rotating a little the distributor - if I was rotating "more than a little", it was getting worse for sure.

https://youtu.be/YibRPR9ARRg

So my thought was to perform several actions first: refurbish carburator, verify spark plug seats, and also perform that "continuity timing test" you show; this is the ones that I could not reproduce. once I had all those checks done, I would re-do the test at idle.
I now plan first to do all the coil+spark verification you show in the other video, on top of the other actions.

But I really want to get to the bottom of this... if there is one thing I have learnt during those last 6 months, it is that if something is not different from MM recommends... there is likely something wrong.
Thank you for the "power testing" procedure. It will of course have to wait for that block to be back in the boat!

Thank you for everything over the past decades, keeping those blocks alive! This block is my age, and i am really trying to save him... emotional, not reasonable.