VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc '33 207 Not Running

Hello All,

I am reaching the end of my '33 firetruck restoration and am having an issue with the engine running. The truck has started and ran at idle for some time now, but as I have started to take it on some test drives it wants to quit running. It starts well and idles but as I drive it, it starts to miss and then quits altogether.

I at first thought it was a fuel problem as I have had the fuel tank boiled out and had not installed a filter to catch any small trash that may have come from that. I cleaned the carburetor and found some small particles, but not a lot. There were also some small particles in the glass bowl before the fuel pump. I installed an in line filter, started and drove the truck with the same results.

I am now wondering if this is an ignition problem. Could the coil be getting hot and dropping out? The distributor cap, wires, points, condenser, rotor and plugs were all new when I started.

I will add that after my trip last night I pulled the cap and there appears to be a very fine dust on the plate that holds the points. There is no obvious wear on the cap or rotor that this might have come from. All ignition parts were purchased at the Filling Station.

As a note, the fuel tank sits behind the seat so I do have some head pressure to the fuel pump so I don't believe this is a vapor lock.

Any thoughts on where to check next are appreciated.

Thanks

I have had spark coils act like that. They work OK when cold but start to cause rough running when hot and eventually even quit . Once they cool off they would work OK again. If you have a spare it would be easy to change it and see if that is the problem.

OK, I thought that might be a place to start. I will have to round up a coil to check it with. Thanks

I had a similar problem that was more insidious. The ignition switch was grounding the coil wire. Once I bypassed the switch all was fine.

There is a quicker way to check for an overheated coil. Just pour cool water on the hot coil. If the spark returns it allows the engine to run and verifies the problem. I have had the problem numerous times. Low vehicle and engine speeds produce the hottest coils.

Hi Chipper, good to hear from you again. Have you ever had to modify an eletrolock coil or have you seen it done?

Another possibility is the little fibre block that rubs on the cam maybe wearing, this will cause the points to close. Put a smear of grease on the cam, in a side of the road stoppage a drop of engine oil off the dipstick will get you out of trouble.
Tony

I have never had a '33 so don't have any experience with modifying the coil. Coils have a positive post, negative post and center high voltage contact. Might have to do some wiring magic to install a replacement to see if that is the problem?

OK, thanks. I'll do some checking

The ignition circuit is fairly simple. Power to the positive post. Negative post connected to the points (switch) that open interrupting current flow then closing to reestablish flow. That pulsating current causes the coil (transformer) to produce high voltages that can jump the gap in the spark plugs igniting the gas/air mixture.