Technical GM Points Distributor no sparky

Little back story before I get into the nitty gritty, had this distributor rebuilt by a somewhat local guy that's pretty good, adamant about using older hard to find quality made parts, went 7200 before it showed point float on his machine.
I ran it this way for a few years without issues, then I put a Crane XRI points eliminator with it's built in rev limiter in and got a few more years of trouble free use.
Took the car to a cruise night and came back to the car to find a guy and girl sitting in it, after a not so subtle discussion of the error in their ways I fired it up to go home, car ran like crap, two footer at all the stoplights. I figured they probably stomped the gas a few times and fouled the plugs, aggravating but no biggie, changed plugs, didn't help. New cap, rotor, coil, different plug wires, different coil, different cap, different rotor all to no avail, still wouldn't idle and carried a miss to the 5,000 rpm I ran it.
At this point I think the issue is the Crane XRI, pull that and put the old points/condenser back in and it won't even fire, try a different set of points and a different condenser and still won't fire. I stick a dual point distributor in and it fires right up with no misses and no issues for the last 10 yrs.
I've tried the old distributor a few times over the years with the same result, no fire, I've ran a continuity test on a couple of the wires leading to the points and all is good.
Now, take a look at the photos and see if you see something that I'm not seeing, because I surely don't understand why this distributor won't work anymore.



There's this much movement (gap) with rotor pushed down



And pulled up

 

I'm sure the experts will chime in, but have you checked with a meter the ground of the distributor body to the engine, frame, etc.? It all looks o.k. from the topside to me. If you have a decent coil, you should be able to manually open/close the points and see a spark. I remember there is a gasket that fits underneath the housing to the motor, just for grins might take it out and see what happens. BTW, i've used the single and dual points type for the cap size vs. HEI, finally sucked it up and went with the MSD ready to run small top unit (same size as the DP)--huge difference, no problemo. Its only $$$.

 

Have you checked the wire from the points to the coil, for a short to ground? and for continuity? Might have something funky somewhere, we can't see it in your pictures.

 

From the pic, looks like the lug on the condenser wire is touching the points plate...?

 

could be.

An ohm meter will be a big help figuring it out. The coil wire to ground resistance should change drastically as you rotate the distributor, and the points open and close.

 

@Doublepumper put a hole shot on me while I was editing one of the photos.

 

From that camera angle, it sure does. Won't that be a pisser if that's all it is.
I'm with Jim, check the wire going to the distributor for a short or an open circuit.

 

Are you sure it's ignition? Sure they didn't get angry and put something into the gas?

After the fact it drive fine, then slight altercation then after trying different distributors the same problem persists.

I'd drain the carb, put fresh gas into the carb and see how it runs while it burns the known clean fuel in the bowl.

.

 

With the wire from the coil disconnected and the points open, do you have ground on both sides of the points?

 

Well that end on the condenser wire is positively upside down. That we know for sure.

For me this is an an absolute first in 60 years of working on cars. The first time I ever saw anyone put a condensor in a Delco adjustable point distributor backwards. This is the correct orientation of the condenser

 

No big deal, but I always put the condenser in aiming the other way. Pair up the hot terminal and the condenser terminal and slide them down on the screw.

 

I had checked the black wire for continuity but honestly don't really know how or what to check with a multi meter with the distributor out of the engine and not hooked to power.
I'm wondering if the condenser would've been touching on all the different ones I tried, seems odd if they all were.
I'll go out and look at it after dinner or tomorrow if you guys let me know how to check what with a meter.

 

You might save some time and grief by looking at my post #11. We all have a brain fart once in a while.

 

My vote is the condenser wire also.
You need the take the condenser off and have the wire coming out the other side going to the points.
And the clip on the condenser lead needs to slip over from the top not the bottom.

 

hmmm...yeah, learning about how to use a multimeter to do lots of different tests seems to be a "black art" to many people. Sorry about that. But it's really pretty simple to use the Ohms scale to check for shorts or continuity. Put the meter on the Ohms scale (Ω), one with a low number like 20 or 200. With resistance, a low Ohms reading means the two things are connected together. A high reading (usually infinite, which displays in different ways on different meters) means things are not connected together. You can see this by connecting the test leads to each other, you will get a low number reading. Then disconnect them from each other, you will get an infinite reading. Just remember that one of those readings means connection (closed, or short, circuit), the other means disconnected (open circuit).

So...if you connect one lead to the distributor body, and the other to the coil wire coming out the distributor, you'll probably see a low reading, indicating a short circuit. Rotate the distributor shaft, see if it changes when the points open. If not, Disconnect that condenser wire, see if it now has an open circuit...or maybe it will be a closed circuit, until you rotate the distributor shaft a little so the points open up, then it should be an open circuit.

does that help?

 

Put a new Crane XRI back in it...at least it ran with the original one.

 

If I understood, using ANOTHER distributor made it run hunky dory.

Ben

 

Yes, when I put the dual point in using the same coil as I tried with the single points it ran great right away and has been for 10 years.

 

But it didn't run great trying to get home from that cruise night, would not staying running at low rpm, that's why I had to two foot it all the way home.
That's why I also think it's something in the distributor not related to the points.

 

After the umpteenth time of swapping stuff I might have just stuck it on there in any old fashion, to just put it back together so I could drop kick it out of the way onto the shelf, who knows.
I've certainly changed many points and condensers in my lifetime, including setting up the dual point in the car now.
I am glad I showed you something new though lol

 

You could..... ditch the points and install a Pertronix module...
Just had to say it...LOL.

 

Can there be excessive up and down play in the shaft effecting it somehow ?
I don't know how it could get out of adjustment but I'm not sure what the tolerances are supposed to be either.

 

The end play being out of spec won't make it not run.