VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Backfires and almost dying

Hey all,
I just want to double check with the experts here... My '38 is backfiring a lot lately, and anytime I turn the car to the right or make a sudden stop, she almost dies. If I turn to the left its fine. I am thinking I need to rebuild the carb, however, I would like the experts opinion here.

Thanks,
Davis

First check the ignition wiring and distributor. Look for a wire that moves toward a ground when turning or stopping. Also look over the spark plug wires carefully. At night with the lights off is another good time to check for voltage leak. Also check under dash for switch wire being loose or touching another wire or ground. Once you have ruled out electrical then look at carburetor. Moderate speed turns or stops should not cause a difference in performance unless the carburetor is loose on the manifold.

Is it back firing trough the exhaust or carburetor?

Along with the above, also check the float level in your carburetor and also your timing.

"After-Fire" = through exhaust ports, exhaust manifold, exhaust pipe, muffler and tailpipe

"Back-Fire" = through intake ports in head and out through intake manifold and carburetor and air filter.

UR welcome. Mercy!

Charlie

first port of call

http://www.international-auto.com/f...tips-on-reading-gauges-vacuum-gauges.cfm

ollie

Check the coil too.

They were in fact backfires. However, it turned out to be the ignition wire shorting out. Glad I checked with everyone on here first, you guys never disappoint. Rewiring the electrolock tomorrow.

Thanks for all the help!
-Davis

Hi Davis,

Following is the previous discussion we had on rebuilding/repairing the electrolock on a 40's vintage car/truck. I am assuming they are about the same as on your 38?

1946 Chev 1/2 ton Ignition to coil wiring

Good luck, Mike

I reused these directions in the spring when I shorted out my wire because I didn't have the cap secured well to the top of the coil. Fortunately, I was only a block from home and two of my former high school students pushed me home. I was also turning a corner. Likewise, my engine miss fired, but also the wire insulation burned and smoked because I had previously rapped the fastener end in electrical tape. I had no problem identifying where my problem was!!! I'm just glad I didn't decide to touch it. It was extremely hot!!!

P.S. Reposted link to previous chat discussion.

That word, "Back fire" is often misused. It actually means blowing back through the carburetor. Through the exhaust it is called "muffler explosion". Two different problems.

Sorry, I didn't see this when I posted.

Back in the days of the manual spark advance, you could cause a loud muffler explosion.