rough running after new carb

[winebros1]

Good morning and Happy Labor Day. Posting again. I have a new carburetor, new coil high performance, new spark plugs (autolite gapped to .032) and the VW distributor from Texas T parts. I also have the alternator from Texas T as well. I fried the first coil because somehow I got the firing order incorrect on 3 and 4. Fixed that and replaced the coil. But she still runs rough and it is random. How do I check the points and what am I looking for? This is all 12 V. Ive read a lot of guys prefer the 6 volt and some even say go back to the original. Im thinking of doing that but this did run before and was drivable with this setup. Please help. Thanks guys. I love this forum. Anyone in the Denver area I would be happy to pay in cash or beer for hands on help too.

[MichaelPawelek]

You have a whole lot of new parts going on so you will have to take each new part one at a time and test.
What is the point gap set to? 20-22 Thousands?

Is the timing correct? With engine running and not getting your hand mangled in the fan blades can you rotate the distributor body and smooth the engine out? Are the plug wires going to the spark plugs in the correct firing order?

Have you tried to adjust the carburetor while running and is the float level ok.

[TXGOAT2]

Coils rarely fail. Incorrect firing order would not damage the coil. Incorrect firing order would make the engine run very rough, if you could get it to start at all, and it might damage the starter. Whatever damaged the coil may have damaged the points. If your ignition system requires an ignition resistor, lack of one, or an incorrect one, may have caused damage to the coil and points. Adjustment of point gap, spark plug gap, ignition timing, and carburetor are necessary for good engine performance. I'd examine the points for any evidence of pitting or burning of the contacts, and replace them they don't look perfect. If you have a twelve volt battery and alternator, you may as well stick with the 12 volt ignition system. Read all instructions that came with the ignition system very carefully and follow to the letter. If you don't have the instruction material, it may be obtainable online. Be aware that replacing the ignition and carburetor will not correct probelems not directly related to them. (Why were all these parts replaced?) A high performance coil is not necessary for a Model T and may not be compatible with the ignition system you have. A dirty fuel system will quickly foul up a new carburetor.

[John kuehn]

The Texas T website has a downloadable instruction sheet that’s for the Volkswagen distributor you have. It gives a list of replacement parts if you need them and the recommended settings for the plugs and gap setting for the points. If the distributor is like most it has points that are usually adjusted the same way.
Take off the cap and using the hand crank turn the engine until one of the lobes on the distributor shaft raises open the points. That’s the point gap.
There is one screw that you loosen so you can carefully move the points back and forth to get the recommended gap.

You might also replace the condenser to see it that helps.

Other issues can cause what your describing also. Old gas, fuel restriction and so on.

[Norman Kling]

A few questions: Why did you replace all these parts? Was it running before you replaced them, and if so, has anything changed since your replacements, or is it still the same as before?
What kind of carburetor do you have, and are there any modifications to the engine such as modified camshaft, stroke or head?
Some other things to check would be compression in all cylinders. Valve timing vacuum leaks at the manifold. Sticking valves can also be a problem. Etc.
If the car is running rough, it is a good idea to make many tests first and then replace one part at a time until you find which one is causing the problem. In fact, if you have more than one T, and one is running smoothly, you can even switch parts, such as the carburetor. Then see if this changes your problem car. That way, you don't need to buy new parts which might not be needed.
Other possible problems would be partially clogged fuel system. This can be caused by foreign particles such as rust, or water in the fuel. It can also happen if the car is not driven for a long time such as a year with the fuel still in it. Old fuel sometimes gets hard like varnish and clogs the small passages such as the fuel line or carburetor.
One possible cause of burnt points would be a bad condenser in the distributor, or if the ignition switch is left on and the points happen to be closed, it could overheat the ignition coil.
Anyway, good luck.
Norm

[winebros1]

Is there a way to test the condenser? I did re time and it was off a bit. Points look good

[TXGOAT2]

The best test is to replace it. I'd also try a standard coil made for use with that system.

[MKossor]

I had a similar experience after getting my FULLY rebult engine back from an expert rebuilder who installed all A list name brand parts. Got it all back together and installed in the car and........ The Car ran like CRAP.

Swapped back the old carburetor that ran great, installed an E-Timer to remove ALL magneto timer and coil point variables and...... the car still ran like CRAP.

Turned out to be the Brand new, beautiful, expensive Champion X spark plugs gapped to 0.025" as per manufacturer instructions! Put the old beat up tarnished Champion plugs back in with the exact same gap and the engine ran Excellent. Still have not figured out why, want to get a spark plug tester to test and understand why. Some say they need to run with wider gap but have not tried that yet without a way to see what is going on. Interesting and unexpected result. Hope sharing my experience helps you and others.

[tman1913]

If you don’t have a ground wire between the base of the distributor and the engine block, install one.