Timing issue or dizzy problem?

Bob/Kansas City

Bob/Kansas City

Senior Member
Ok.. I'm running out of ideas on the engine in my roadster. The car sat for 28 years untouched and I've got it running now with rebuilt carb, completely rebuilt distributor, new coil, plugs and leads etc.
I timed it at full retard and followed everyone's instructions for adjusting the dizzy cam, points etc.
The engine starts easily, idles beautifully and will easily rev up using the throttle lever on the side of the carb.
The problem I have is as soon as I start to advance the spark lever to normal driving position the engine dies immediately. If I quickly retard the spark lever it will catch again and run great.
Do I have my timing too far advanced, a short in the dizzy when the upper plate moves or what?
Does anyone have any ideas?

Just as a sidelight it was quite a sight when it first started after sitting for that many years! I had oiled the cylinders with ATF and Marvel Mystery Oil and let it sit for a week. Every day or so I would turn it over with the crank just to begin to loosen it up. After a couple of days of cranking by hand I could feel good compression so had high hopes it would start.

I hooked up a new battery and cables and when it caught for the first time it coughed a couple of times then belched out huge clouds of smoke along with bits of mouse nest, mouse turds and even the little green bits of mouse poison they had carried up into the tail pipe! It blew this mess all down the driveway the first time I gave it a little goose of the throttle!
It's amazing how well it runs now after that initial clean out! I may have a good one in that there are no knocks and no leaks at the rear main or anywhere. Next step is to take a compression test then drop the pan and take off the valve cover to get everything cleaned out. The fun begins!
 
There is a little wire under the top plate that connects to the bottom plate. The shielding on these wires can wear off and I would check that first. It may be touching the side of the distributor when you move it and shorting out on the body.
 
The arm from the steering column to the dizzy is hitting the dizzy cable when you advance the lever. Raise the hood when its dark and run the engine...see anything arching on the head?
 
You say the engine will accelerate well in full retard. When properly timed, you will have some hesitation as you rev it up. If you do not have this hesitation in full retard, you may to adjust a little more retard.
 
I've fought the demon that Jason is referring to, and ended up grinding off an eighth-inch of the lower distributor plate tab that connects to the ignition wire in the bottom of the distributor. It would only touch the bottom of the distributor occasionally as I would move the advance lever. Do you have a modern points setup? You can also check for a short there by turning on the ignition key and check for continuity between the points arm and ground. Hold the points open with a small piece of paper, matchbook cover, etc. if you have some help you can check this while someone moves the advance lever back and forth to check for trouble.

As far as timing, I found this article by Marco to help me understand timing and adjustments....
http://www.abarnyard.com/workshop/timing.htm
 
It sure sounds like the wire for the lower plate is touching the spring or some other ground when you advance the spark lever. The wire terminal needs to be bent at 90* and positioned as Marco has shown in the past. Wish I had that picture handy. Anyway, study the terminal and position it so it won't touch ground as the top plate is moved.
 
Jason in TX said:
There is a little wire under the top plate that connects to the bottom plate. The shielding on these wires can wear off and I would check that first. It may be touching the side of the distributor when you move it and shorting out on the body.
Click to expand...

This was my first thought as well.
 
Jason in TX said:
There is a little wire under the top plate that connects to the bottom plate. The shielding on these wires can wear off and I would check that first. It may be touching the side of the distributor when you move it and shorting out on the body.
Click to expand...

I just replaced this wire yesterday.The insulation was in sad shape.

On a side note I also had a problem with the main jet from the carb rebuild kit being 3 size's smaller than the original. That lead me in a big circle that started with the carb and ended with the carb.
 
Tom, that old post is exactly the problem I'm having. I didn't bend the flag on the wire where it connects to the upper plate and I'll bet it is grounding out on the dizzy body.
I'll take the dizzy apart today and fix that and will retime with a little more retard to see if I can get the timing closer.
I'm sure glad you remembered that old post and I'm grateful that help like yours is available on the barn!
Thanks very much to all for your help!
Bob
 
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