123 dizzy and engine sputtering

I have been driving my Elf with a brand new 123 dizzy on a fresh rebuilt motor for the past 6 months. I had it stumble on me once or twice a long time ago and thought it to be a cold morning because it would only happen once then nothing for weeks. Now that I have been driving it more often I am getting the situation more often. While driving at around 70mph or so, the motor will cut out in rapid succession for a few minutes then would recover. After the engine cuts out a few times I then get a backfire through the carb.

I removed the vacuum advance tube and found fuel in it, but after driving with the vacuum advance blocked off I still get this event happening. I drove all day yesterday and it wasn't until later in the day when on my way home that the cutting out and backfire through the carb happened and that is the way it happens in other instances.

I now have ruled out the idea of the coil since I changed from a Pertronix unit to a Bosch blue and the condition still arises. I ruled out carb icing with making sure the heater line passes through the intake and that the condition arises even when the air temperature is in the 70's . The fuel delivery shouldn't be the culprit since i can accelerate and still feel the cutting out of the engine. Dizzy cap and contacts are clean and new leads are fine.

My next thought is that the 123 is having a problem or that the charging system isn't keeping up with recharging of the coil after a long distance run. I can't recall that the condition has arisen when the lights are on, but I am thinking that the dynamo isn't putting out enough juice and when I turn the headlights on the regulator gets more juice from the dynamo and now can power the 123 or the coil with sufficient energy. Any thoughts?

Also,
I have a new Magnolia faced Smiths gauge with RCV1006-02CA printed on the back. I want to install it in my Elf. The engine has a 123 dizzy, currently running a dynamo (want to change to alternator) I looked at the installation instructions, but unsure what to do about the calibration switches on the back of the gauge (mostly about what type of signal input) and would I connect a wire (white/black) to the dynamo and the other to the low tension side (red/blue) The other wires like green and the black are kind of self explanatory like connecting to the ignition and a ground. Anyone done this before and any help to exactly where to put these wires so I don't fry the tach will be greatly appreciated.

Hi

I would be inclined top have a chat 123 and see if they have any suggestions as I think these are a bit more complicated inside. By the way what do you think of them (miss fire aside) as I was looking at these myself. Do I presume that you are already running a tach ? - Have you tried disconnecting it to see if this cures the problem as a tach can cause the ignition system to fail if it faulty, especially Jaeger (I know this from past experience) - some units interrupt the ignition feed to sense the revs (ie jaeger), whereas others just monitor the pulse thro an unbroken wire (ie smiths), so when a jaeger type has a problem it pulls down the ignition system.

I will have a dig about and see what I can find regarding the new unit

Hope this helps a bit

Gordon

I added the tachometer to see what was happening while the stumbling was occurring so it isn't part of the problem.
I found the information I needed to install the tach on the ignition. The Blue/red goes to the negative side of the coil, Red/White to the dash lights, Green to an ignition switch power and the Black to a ground. I utilized the White/Green wire of the oil filter light to connect to the negative of the coil, the other half of the wire that connects to the light in the dash was connected to the Blue/Red. The white wire for the oil filter light in the dash was my switched ignition and the other wires got to their color coordinated destinations.

I really like the 123, gives smooth timing and you can choose from different advance curves to optimize the ignition.

My engine builder suggested that I first check the wire that is feeding the power to the coil to rule that out and I found the wire loose within the connector so I have crimped on a new connector and will have a drive to see if that is it. I hope it is because the 123 dizzy is a really nice bit of kit and the adjust ability is a boon. Even if the dizzy is at fault, I would be happy if it gets replaced with a new one.

My theory about my voltage regulator helping the distributor when the headlights were on was kind of true. My local Mini guru found that my regulator was allowing 15 to 16 volts to get past and might have been over powering the 123dizzy causing it to fault. When I drove with my headlights on I know I never felt the engine cut out, so when the lights were on, the voltage dipped down to proper 13volts and the dizzy ran correctly. I now have a corrected voltage regulator and replaced the 123 dizzy with a Pertronix modified Lucas unit to weed out if the dizzy was causing the problem. I am sure that the overpower of the dizzy had to have an ill effect on it's running.

Anyway, I think the engine bay looks much better with a more original looking distributor. The 123 is a good bit of technical equipment and would look good in a newer styled Mini, but for my Elf that is trying to keep the vintage look, the Lucas is the way to go for my aesthetic.

Also, while my car was at the shop I had a set of adjustable diagonal tie rods and adjustable lower arms added with poly bushes. I also had some camber brackets added in the rear. Wow, what a difference. The car maneuvers nicely and precisely and there is no more harshness.