1950 won't run

[plym_46]

there was just a very comprehensive discussion of fuel starvation problems on the P15 D24 forum,  this was on a Desoto.  visit and check it out.

Simple fuel flow test mentioned there as well as a myriad of other things to check to assure proper fuel flow. 


http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=10088

[Alan_Hepburn]

Thanks for the help everyone...

I'm reasonably sure we set the float level correctly - if I recall the sheet that came with the kit said it should be 5/64" and it's pretty close to that. When it stalls we can work the throttle and see fuel being squirted down the throat.

I know it has a new coil and plugs, but he hasn't replaced the points, cap, condenser, or wires yet - maybe that's the next thing we can try, along with wrapping the fuel line with a wet rag. The previous owner sort of converted it to 12V - he put a 12V battery in  but didn't change anything else so far as we know. We replaced the original generator with a 12V alternator when we put the  new wiring harness in, and the coil is a 12V coil. Is it possible that the 12V is causing problems?

[TodFitch]

I have heard it said that 90% of all carburetor problems are electrical. :)

The condenser and coil are both items that can heat up as you run, not from the heat of the engine but from the current going through them. If either has a problem hot they can manifest themselves with symptoms very similar to running out of gas: Stumbling then quitting.

So, remove the air cleaner. Let it run until it stops. Pump the throttle once while looking down the carburetor throat. If you see gas then the problem is not fuel related. Pull a plug wire, hold it with insulated pliers close to the block and try to start the engine. Look for the quality of the spark. It should be bright and white.

[36 Ply]

A couple of ideas,if it is indeed fuel related.

The old timers used to wrap a water soaked rag around the fuel line when vapor lock was suspected.

You could add an electric fuel pump near the gas tank (they are pushers,not pullers); they usually cure vapor lock.
If you are still setup with 6 volts, Summit Racing sells a 6 volt electric pump that can be either positive or negative ground. Let me know if you need the part number. They are a little over 100 bucks, and you may also need a 30 dollar fuel pressure regulator, if you go this route. The Summit pump puts out about 6 1/2 psi, and your original mechanical pump may be closer to the 3 psi neighborhood. I can look up the figure for your original (mechanical) pump if you need it. The fuel pressure regulator is so you don't flood your carb, which will also cause stallling.

You didn't mention what kind of fuel filter you have, but a transparent one will let you know if dirt or other stuff is coming out of your fuel tank.

I'm sure other members will be posting ideas.

Regards,

Pat O'Connor

[chetbrz]

What you mentioned sounds like a good possibility unless you have a gas filter somewhere between the fuel pump and the carburetor that could also be slowing down the gas flow.? Letting it sit for a minute or two would then allow the pressure in the gas line the ability to restore gas to the carburetor and fill the bowel.? ?Maybe for a quick test you could provide some type of insulation between the gas line and the exhaust manifold to determine vapor lock, if not I would suspect any gas filter in the system.?

My humble 2 cents.? Chet?

PS? My assumption is that when you rebuilt the carburetor that the float was setup properly.

[Alan_Hepburn]

My son and I are trying to get his '50 Plymouth hotrod running, with little luck. It's got the original engine in it, and it will start up and idle fine for about 5 minutes or so, then it acts as if it's out of gas - it'll stumble and then stall. It'll restart after a minute or two and then run again for a few minutes before it stalls again. We've replaced the fuel filter and this past weekend we rebuilt the carb to no avail. I'm wondering if we're getting vapor lock? The fuel line from the pump up to the carb is about 3 or 4 inches from the exhaust manifold, and it gets pretty warm. We're thinking about rerouting that line away from the manifold but we're wondering if that is the problem, or is it something else?

Anybody got any good ideas we can look at? He's anxious to get the car on the road!

Alan Hepburn