Won't start hot

[DodgeDan]

Greetings all. My car is a '39 Dodge, but I was hoping I might get some help here. I have a flathead six. I have been restoring and bringing it back to life for the past two years. I am to the point where I am ready to drive, (at least I thought I was). The car always starts and runs fine, but now after driving the car for it's first short excursion, which was only a short distance of about five miles if even, it quit on me, I was able to restart it but then it quit again a short time after and would not restart. Any ideas on what might be going on? The carb is rebuilt, all ignition wires are new, fuel pump is new, fuel filter is new, cap and rotor, points and condenser are new, plugs are new. Disappointing...

Regards;

Dan

[Captain Neon]

Any 6v coil will do. Autozone has them on the shelf at most (if not all) of their stores. Save your money with a new coil rather than getting NOS. You will be glad that you did.

[DodgeDan]

Thanks for the replies. I'll try the coil test. My coil is mounted in the firewall, and only has one side terminal, so a cheap aftermarket one might not work for me.

Dan

[Captain Neon]

One terminal is hot and the other is ground. Just run a grounding wire and it will work great. However, I can't stress how important it is that for something like this that you buy new rather than NOS.

[greg g]

The other thing you should check is fuel flow. If the car has been sitting for a while there is no telling what might be flowing throughthe fuel lines. An easy check it to disconnect the fuel line from the carb. Direct the flow into a suitable container (a plastic water bottle will work fine) Witht he coil wire out,of the dist, crank the engine Have ad assistant do it, while you count the pulses from the fuel pump. count 12 or so pulses this should give you about 8 ounces of gas in the conatainer, if not you have some line blockage. You can also disconnect the fuel lie from the tank side of the fuel pump and blow some compressed air back through the line toward the tank, this will clear the line and the intank filter.

Also check you float level, a lot of us have found that setting a bit lower than factory spec works well with todays gas. You might be fighting a perculation problem. Fuel sits inthe bowl and expands overflowing the bowl. This causes the car to flood. Look for raw fuel at the ends of the throttle plate pivot pin. If there is fuel there this could be the problem.

Also when starting hot do not pump the gas, floor the pedal and crank the engine, this will help clear it if it is flooded.

The ignition wire to the coil is on the inside of the firewall. Its there just in a different spot.

One item to check in the distributor. There is a wire connecting the coil terminal to the points. Sometimes this will look fine but most of the strands will be broken from years of flexing with the breaker plate. Or it may have insulation worn off and is grounding against the body of the distributor.

Also a failing coil will be too hot to touch. A working one will be warm but notoverly hot.

[JIPJOBXX]

I had the same problem with my 42 and the coil was the problem. Good luck and hope that fixes your problem.

[DodgeDan]

I really appreciate all the help from everyone here. I knew you P15 D24 folks could help, many similarities with my '39. I'll have at it over the next few days with all your recommendations and see what I can come up with. The car would run as long as I had my foot on the gas, once I let up she'd quit. Thanks again.

Dan

Edited May 21, 2009 by DodgeDan

[old woolie]

I really appreciate all the help from everyone here. I knew you P15 D24 folks could help, many similarities with my '39. I'll have at it over the next few days all your recommendations and see what I can come up with. The would run as long as I had my foot on the gas, once I let up she'd quit. Thanks again.

Dan

That doesn't sound like coil trouble, sounds more like flooding at idle, high float setting, dirt in needle valve, etc.

greg g's advice was very good.

Edited May 21, 2009 by old woolie

[dirty dan]

He said on the first post that it would quit and then wouldn't re-start...That sounds like a coil.

Later on he said it will stay running fine as long as he keeps his foot on the gas... That sounds like float adjustment.

If it were mine, I'd recreate the failure and let it stall. Then while it won't start see if you're getting spark. If you are getting spark, try holding the gas pedal to the floor while you try to crank it (like your starting a flooded engine). If it's not flooding, I'd replace my fuel filter. If that doesn't fix your problem, into the carb you go!

[desoto1939]

I am assuming that you have 6 volt battery cables on the car and also a good grounding stap to the frame.

If you are using 12v battery cables the car will start when it is cold but after driving the car and it gets up to operating temp the system is not carrying enought volt to get the system to fire over. It will crank slowly and then will eventually fire.

I have a 39 Desoto which is the sister car to your Dodge. I also have a hood for your car if you need a spare.

I can provide a great deal of information on the various parts also such as electrical parts etc.

Rich Hartung i live near Valley Forge PA

Desoto1939@aol.com 484-431-8157 cell

[DodgeDan]

Sorry for the confusion. Here is what I experienced; I was driving along a few miles at about 35 to 40 mph, I slowed down for a railroad crossing and when I let up on the gas to slow down it quit. I coasted to the side of the road and restarted it. I drove along again a few more miles, and I reached where I was going, again I slowed down as I approached the driveway, when I let up on the gas it again quit. This time it would not restart. I had a friend pull me back home. Later after I got home from work that night I went out to see if it would start and it started fine. It is indeed 6v pos. ground and I am using 6v cables.

Dan

[greg g]

UH OH Now will begin the dreaded vapor lock comments......

Any way assure there are no air leaks in the fuel line on the tank side of the pump.

[TodFitch]

Did you clean out the gas tank when you were working to get this car back on the road? Your symptoms sound to me like some dirt has gotten into the carburetor. You mentioned a new fuel filter. Is that on that has transparent walls? If so, does it still look clean?

[DodgeDan]

Okay, the car had an electric fuel pump on it when I bought the car two years ago. As part of my restoration over the last two years (the car had sat for 20 years untouched in a garage), I took the electric fuel pump off and reinstalled a new mechanical fuel pump, all new lines, and dropped the fuel tank and completely cleaned it out with muriatic acid. Today, I swapped the fuel filter for a new one, yes it's the clear walled kind, the old one was not bad but I changed it anyway as they are cheap enough. I also dropped the sediment bowl on the fuel pump and emptied it out and cleaned it. I removed the fuel line going into the float chamber and cleaned the needle valve. When I pump the carb I see good fuel action down inside the throttle body. My gas is good. I would like to check the float adjustment but am not really sure how? My carb is a Stromberg, I need to know what the proper measurement is and how to measure? On the Stromberg, you cannot remove just the float chamber cover, it is all one piece and the entire top of the carb comes off.

Dan

[JIPJOBXX]

Did you try the ice trick? I did that on my Dodge and that's when I found out my coil was bad.

[Normspeed]

Sorry for the confusion. Here is what I experienced; I was driving along a few miles at about 35 to 40 mph, I slowed down for a railroad crossing and when I let up on the gas to slow down it quit. I coasted to the side of the road and restarted it. I drove along again a few more miles, and I reached where I was going, again I slowed down as I approached the driveway, when I let up on the gas it again quit. This time it would not restart. I had a friend pull me back home. Later after I got home from work that night I went out to see if it would start and it started fine. It is indeed 6v pos. ground and I am using 6v cables.

Dan

I'm thinking the little wire to the points inside the distributor is shorting against the housing. When you let off the gas the vacuum increases, and the vac advance rotates the distributor plate. If that points wire has bad insulation or if the wire is breaking at the connection to the case, you get a no spark situation. Same might go for the part where it runs at full throttle only. Different vacuum signal, points plate rotates, wire shorts against the case. Just my $.02.

[DodgeDan]

I emailed Clive at Stromberg Carb today. He told me there is a measurement but a good rule of thumb is to turn the carb upside down, the top of the float should be flush with the top of the float chamber. I pulled the carb and mine was slightly higher than the top edge of the chamber, so I lowered it so it was slightly lower than the top of the float chamber. Then I reinstalled the carb. I fired her up and she's running fine, but I have not ventured down the road yet, I want to make sure I have someone available to pull me back home if need be.

I let her run quite a while, the coil did start to get almost too hot to touch. I don't have any ice so I didn't try the ice to test the coil yet. I shut her down and went to restart her and she started hard, then didn't start at all. I have not looked at the distributor point wire yet, still need to take a look there. I'll keep you posted.

Dan

[JIPJOBXX]

Just like mine, did you check to see if there were any cracks in the coil?

[Don Coatney]

I suspect you may have a slight leak in your fuel line from the tank to the fuel pump. With heat (somewhere near the fuel pump) this leak allows air to enter the fuel line and the fuel pump will not suck air. Look for and fix this leak.

[DodgeDan]

Well, I'm good to go now. Replaced the coil, adjusted the float, and replaced the flexible fuel line just before the fuel pump with the correct line with brass fittings, as mine was just a piece of neoprene line hose clamps. She's running good and not quitting when hot any longer. Thanks for all the help.

Dan

[greg g]

It great that you got it runing good but with all those changes, you still don't kow what caused the problem if it reoccurs. Hope it won't.

[DodgeDan]

I'm convinced it was the coil. The coil I removed was the original coil, and it literally fell apart it because was corroded inside so bad. I had it running good after that, and then I adjusted the float and swapped the fuel line just for good measure and two less things to worry about down the road.

Dan

[greg g]

Well if it fell apart, that probably a good indication that it needed to be replaced. Glad its now an on the roader.

[normf@centurytel.net]

Not sure I'm doing this correctly, but here goes. I have 1953 B4B with 11K miles on the engine. Ignition system is new (wires, points, condesor, plugs, rotor, cap and coil) Was hard starting both cold and hot. Reset float level (was too low) Replaced the needle with one from a Holley carb with viton rubber tip..... there is a new fuel pump and the carb has been cleaned. Carb is a Chrysler Ball & Ball. Seems to be flooded on restarts when hot. Should there be a heat block between the carb and the maniforld? Any other ideas....runs good when running and cold starting is now decent. Fussy, but it does start with minimal cranking. Coil is new and there is good spark when hot..... Any other ideas would be great......really frustrated......

[Merle Coggins]

You may have your float too high now. Modern gas is a little more volitile and will expand with the heat soak when shut down hot. Also, check that your heat riser is in the horizontal position with the counter weight in front of the shaft.

I've also found that my truck needs just a little throttle to start when hot. Either step on the gas slightly with the left foot while cranking with the right, or pull out your throttle cable a bit then crank it up.

Merle