Help she starts but wont stay running

[oldbrownie]

I'm new at this and this is my first post. We saved a '54 from the scrapyard, cleaned the carburetor, new plugs, cleaned points, new intake and exhaust gaskets, Airtex fuel pump. It's an old 12 volt conversion. She starts but will only run with the throttle half open or full and with the starter engaged. As soon as I let go of the starter button she stalls.

[Gordon Maney]

What does clean the carburetor mean?

I would look for vacuum leaks, for one thing.

What is the choke doing? Do you have it open when this is occurring?

Also, pull out a plug or three and look at them to see what sort of color you have after one of these not running so well episodes.

[oldbrownie]

Yes I have a vacuum leak, plugs black and wet. Choke open and the carb took it apart, dipped, cleaned, used the parts from rebuild kit and put back together. I could have missed something in the carb ? I will fix the leak after work THANKS

[Gordon Maney]

Yes I have a vacuum leak, plugs black and wet. Choke open and the carb took it apart, dipped, cleaned, used the parts from rebuild kit and put back together. I could have missed something in the carb ? I will fix the leak after work THANKS

If you have a vacuum leak, you need to fix that now. How do you know you have a vacuum leak?

Plugs black and wet suggest too much fuel. A matter somewhat opposite of the vacuum leak.

Did you do anything with the float level? I am not suggesting you should have, but if you changed it and it is now too high, that could explain the wet, black plugs.

[oldbrownie]

Lets start with the vacuum leak? I left the vacuum line open when I changed the fuel pump.Now I don't know if I checked the vacuum correct? Hooked the gauge up to the intake, when she runs about 18 inches of vacuum. compression 120 to 105 dry throttle open. Did nothing with the carb tonight.I did run her out of fuel and the problem did not change. The wiring is a mess it has things I have never seen!! She will start and run with the starter engaged as soon as I let of the start button she stops?? can I hook up a simple wire to see if she run? I think she has the 24v starter? A two post solenoid on the fire wall some type of ignition box (Leece-Neville Co.Cleveland Ohio) and a 12v distributor. I wont be able to mess with till this weekend Thanks

[Gordon Maney]

Lets start with the vacuum leak? I left the vacuum line open when I changed the fuel pump.

Now I don't know if I checked the vacuum correct? Hooked the gauge up to the intake, when she runs about 18 inches of vacuum. compression 120 to 105 dry throttle open.

Did nothing with the carb tonight.I did run her out of fuel and the problem did not change. The wiring is a mess it has things I have never seen!! She will start and run with the starter engaged as soon as I let of the start button she stops??

can I hook up a simple wire to see if she run? I think she has the 24v starter?

A two post solenoid on the fire wall some type of ignition box (Leece-Neville Co.Cleveland Ohio) and a 12v distributor. I wont be able to mess with till this weekend Thanks

You do have the vacuum leak stopped, now, is that right? It won't run with a big vacuum leak. It won't idle, anyway.

You say it runs when assisted with the starter. That suggests to me it does not run well.

Without standing next to it, the array of possibilities remains rather wide.

One possibility is the mixture is too rich from a high float level. Another possibility is the mixture is too lean from restricted passages or orifices in the carburetor.

You say you cleaned the points. Did you then gap the points? Or set dwell angle? Is this a 24V distributor that has been modified for the conversion?

We have multiple variables here.

[oldbrownie]

I will clean and check the carb this weekend then tackle the points.I know she will run!! Thanks again

[oldbrownie]

SHE RUNS !!!! It was the carb. The float retainer clip was not installed correctly! main jet was loose!! THANKS for all the help!!! I was a bit scared with the other problems with this, now they all seem like little problems.I will keep you posted on the progress. THANKS AGAIN!!

[Gordon Maney]

Great news.... good job.

And, encourages others to look for things they believe they won't find, and therefore not worth looking for.

[Charles Talbert]

A wise move

Checking the compression first off eliminated major internal issues as a likely possibility, a wise move. Compression test is easy and quick, if like in your case it reveals an acceptable reading, you can proceed with accessory component troubleshooting knowing a fairly simple issue will likely be located soon. This is the smartest and quickest way to diagnose, you have proven that theory.

Many have laughed at us for approaching it this way saying why don't you check the more simple things first? Ok, accessory component issues may exist, but if a major internal issue is going on, obviously it must be corrected before any component repairs would make any real difference. What good is a new carb on an engine with 50 PSI compression readings?