1940 Deluxe 8

[ragtop40]

I just bought a 1940 Deluxe 8 Convertible at an auction in Dallas...a really nice car. The motor idles smoothly, but when stressed (1st gear when starting off) it sputters and backfires. I thought maybe it was a vacuum leak, but not sure. Any thoughts?

[Larry]

Congratulations on now having one of the most attractive Pontiacs ever built. Can you tell I kinda like the '40s? I have a little 2519, and could only dream of a Deluxe 8 convertible.

These cars usually suffer from LUS (Lack of Use Syndrome) which is most likely what you are experiencing.

From an ignition standpoint, it should be easy to check the point gap, and clean with fine sand paper if needed. Do the same with the rotor ends and the inside contacts of the dist. cap. Then, be sure that the plugs are nice and fresh. Usually when an engine sputters under load, it is the plugs cutting out. Quite literally, the weak spark is "blown out" just like birthday cake candles making the sputtering. Then when they reignite the next time, there is raw gas (that didn't burn the last revolution) that makes the backfiring. Check all these items and just freshening everything should make a good difference.

If you decide to get some new ignition parts, check with MARX Parts, one of our Featured Commercial Suppliers giving our members nice discounts. Look under "AFFILIATES" and then "Member Discounts." Don't forget to check your local NAPA store too; you'd be surprised what all they still can get.

All this being said, you may still have a carb or fuel pump problem, but go through the ignition first. A weak fuel supply will cause sputtering, but not the backfiring.

I doubt it is a serious problem, just a tune-up one.

Keep us posted.