short running then dieing 1936 V8

J

JanP

Member
Hey guys, I need some help!

My 1936 V8 has the following problem: It starts right up on the first press on the button (choke pulled completely). Then it runs for a few seconds and then there is no possibility to keep it running (gas, no gas keep choke, put it back in,....). Immediately after the engine died you can't start it again. If you just wait for about one minute it starts right up again for a few seconds.

It is converted to 12V, has a Speedway crap distributor on it and a Bosch ignition coil. The Stromberg 97 is just rebuilt and looks really fine. The mechanic fuel pump works great and when i spray break cleaner into the carburetor it always starts.

Thanks for some help to a German guy, who has no one in the neighborhood who can help......
 
I'm guessing that it is running out of gas, do you have a fuel regulator that could be set to low? Or sounds like float needle is sticking and restricting flow. Slowly it fills back up after sitting and allows to start back up only momentarily.
Dangerous idea but works, you should have a button on the bottom side of your starter relay. With you car in neutral (double check and chock tires) ignition and key in run position start the engine from under the hood. Have a plastic water bottle with small hole in the cap and gasoline in bottle. Once the engine starts squirt small amounts of gas into top of carb to see if it continues to run. Starting fluid works the same but I prefer gasoline. If it works you know you have a shortage of fuel problem. Make sure you have a fire extinguisher close by.
 
Can you get a fuel pressure gauge to connect into the line and see what the fuel pressure is doing? Most vacuum gauges will also measure pressure.
 
I opened up the carberator and disconnected the ignition. When I turned the engine fuel flew out of the carb. I think the fuel pump works fine. The swimmer is set correctly, but I don't know how easy the needle has to work. When I blow in, I have to blow hard to get air through the needle. But when the pump works the fuel flows through it.
 
All of the attention seems to be directed at 'fuel supply'.
Have you checked to see if you have spark when it won't run?
 
Maybe the "run" circuit is interrupted in some way; when you start it, it gets current to the ignition from the starter, and when you let off the starter, there is no current to the ignition. I've had this happen to me. Run a temporary "hot" wire from the battery to the coil and see if it keeps running.
 
It could be crud in the fuel tank. I had the same problem years ago and after looking at everything else found a bug stuck in the fuel line at the tank.
 
JanP said:
I opened up the carberator and disconnected the ignition. When I turned the engine fuel flew out of the carb. I think the fuel pump works fine. The swimmer is set correctly, but I don't know how easy the needle has to work. When I blow in, I have to blow hard to get air through the needle. But when the pump works the fuel flows through it.
Click to expand...

"fuel flew out of carb" when cranking?...where is the fuel flying from?.."swimmer"?.....as suggested before, might need to check fuel pressure from the fuel pump....if fuel is flying in just from cranking, it sounds like fuel pump is putting too much gas into carb.....only fuel during cranking should be coming from idle ports unless you mean when the accelerator pump is actuated....just my thots....good luck.....Mike
 
Mike, my guess is Janp is communicating in his second language, as he is in Germany. I think by "swimmer" he is referring to the float.
I think he is saying that there is plenty of petrol coming from the needle valve. (maybe he has the top of the carb off the carb but connected to the pump?)
Keep in mind that the delivery pressure from a mechanical pump is dictated by the spring under the diaphragm. (I assume std. pump here)

My gut feeling is that the fuel side is o.k., and that attention needs to be directed to other basic checks as per 51 Merc ct's advice.
Janp, you need 3 things:
1.Compression.
2. Fuel (in the right quantity)
3. Spark (at the right time)
You obviously are close to having all 3.

Janp,
If you run it until it stops, then remove the fuel line from the pump to the carb.
Now take the top off the carb. If you have a good amount of fuel in the float chamber, you need to look at the ignition system.
 
i realize that there is a language diff, just trying to find out what he meant by what he said....lol....you could be right, tho....figured the "swimmer" part, but don't understand having to "blow hard to get air thru needle"....but fuel pump can blow right thru....stromberg best with 2 1/2 lbs., so is that blowing hard??..thanks.....Mike
 
Last edited:
Thanks for all your thoughts and excuse for my language.....
When I put an ignition light to any of the spark wires, I can see it fires until the engine stops to run. I checkt the ignition point again and its alright. Spark plugs are new again.
I will think about everything you wrote and try it with fuel from another tank with an electric fuel pump. Lets see what happens next.
 
You would be better off if you had some test equipment before you just start changing parts. It is better to figure out what is going on. Checking the spark plugs wires is not going to tell you much, they will always stop showing current flow when the engine stops. What you need to check is if power is still going to the coil when the engine stops (points need to be closed). I would check for fuel pressure to the carb with a pressure gauge and for power to the ignition system, all the way to the coil. That should tell you if it's a fuel or electrical issure.
 
Took of the fuel lines, worked with an extra tank and an electric fuel pump.
It didn't work....think I floated the carb.... Took it all back of, now it runs again.
No idea how I can find the problem now....
 
sounds like you had a blockage and the electric pump pushed it through. If it occurs again, an inline fuel pressure gauge like JSeery suggests will eliminate the guess work.
Good to hear your up and driving again.
 
Last edited:
Check the exhaust pipe, you may have new guests living in the muffler. If it is clogged exhaust you will have to remove the muffler or pipe to remove the obstruction. Before you remove the clog, have some fun, take out every other spark plug and start it up. It will run fine but stand back the exhaust will be spitting out the plug holes. Good luck.
 
JanP said:
Took of the fuel lines, worked with an extra tank and an electric fuel pump.
It didn't work....think I floated the carb.... Took it all back of, now it runs again.
No idea how I can find the problem now....
Click to expand...

Good to hear your car is working again, hopefully it will stay that way! Do you have a fuel filter in the fuel line?
 
I will install another fuel filter next to the tank. The original one at the fuel pump is there too. Hope there is no one in my exhaust, because the car stood in the garage all the time.....
Thanks for your help everyone! Good to know there are guys who like to help!
 
You must log in or register to reply here.
Back
Top