37 dodge brothers fire truck running bad

[Guest lowphat1]

we have a 1937 dodge brothers fire truck and recently it has been running poorly. it will start right up and run after sitting for a while, but then it will just die after its been running for awhile and then it will not start again. i just replaced the 6v ignition coil and condensor. the points on the magneto look fine. the other day when i tried to start it, it spit and sputtered, had an enormously big exhaust cloud around it and then backfired. after that i couldnt get it started again. im thinking problems with the carb?????? any ideas?

chris

[1936 D2]

Magneto? '37 had those? Sounds more like a timing issue. More test data is needed in your post. >>>

How is the static timing? (Timing without engine running).

Backfire - out carb or tail pipe?

Were plug gaps and points gap checked recently? (If off will affect timing).

Tried another condenser?

Did plug wires get moved out of firing order?

Did you remove the distributor? After replacing, center shaft could be 180 degrees out.

Valve spring broken?

Backfiring sounds more like a timing issue than a carb issue. But, you MAY still have a carb or choke issue because of the first comments: running poorly and dying after running a while. Is the choke coming off correctly after it is warmed up? Should be after maybe running one to two minutes (depending on ambient temps).

You speak of a large exhaust cloud. Is it white, blue, or black? If white, water is getting into the cylinders. Possibly a bad head gasket. If blue, oil is getting into the cylinders. Possibly bad valve seals or piston rings. If black, could be a mixture setting messed up. Would usually be too rich. What does that exhaust smell like?

Do some diagnostic tests and get back to us. Good luck.

Edited November 12, 2012 by 1936 D2 (see edit history)

[Guest dbehnke]

I own a 1938 Dodge D8 Business coupe (six cylinder) and experienced similar problems. In my case it was a combination of issues that finally solved my problem. I pulled the distributor and found the insulation had cracked on the wires going to the points causing intermittent grounding. I replaced that wiring and at the same time I installed new points and condenser. I also purchased a new distributor cap and spark plug wires. Once that was completed, I hooked up my timing light to make sure I had a strong spark. I then installed a 6 volt positive gound inline fuel pump, and wired it to a switch on the dash so that I could use it to prime the carb to start. The last change I made however was the one that actually made the most difference and that was I installed a new set of spark plugs. It now starts almost as easily as my daily driver. Hope this helps.