1931 Pontiac tune up problem

[41customolds]

Hi

I put a brand new Zenith carb on my 1931 coupe. The engine runs perfect for some time before it suddenly cuts of. 

If anyone has any idea for troubleshooting I would be greatefull.

 

Thanks 

[Guest]

What do you mean runs perfect for some time.  How long.  Does it just stop like you turned the key off or does it  splutter and stop. Take the cover off the float bowl and see if it is full.  You can run the engine with the top off so leave the top off and crank the engine over to see if it refills.  If the float bowl is full you problem is spark.  If the float chamber is empty then you have a weak fuel pump or maybe an unvented gas cap.

What happens when you turn the key on, does the ammeter flick back and forth as the engine is turning over before it starts.  If it does not then your points aren't opening and closing. Check that you have spark.  As has been said many times most carb trouble is electrical.  If it runs and suddenly stops and then starts okay a few minutes later you probably have a bad coil.  I also could be the spring on the points grounding out inside the dist. Is there any side play in the distributor?

I need exact answers to these questions.  Then I can answer your question.

Do not change the timing or adjust anything until you know what is missing.  You only need spark compression and fuel to run.  You obviously have all three for a while.  It's easy to find the missing one.  Just answer the above questions and we will have your problem solved.

[41customolds]

Thanks again Tinindian. I found out that it was a fuel problem. It just did not act like it. It ran perfect for maybe 10min. Then it just cut right off. 

I found that it didnt get fuel enough from fuel tank. Dirt in fuel tank stopped fuel supply in a very sudden way. Anyway , now it runs great at all times :-)