Carpartz88
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Ok folks I just got this 1952 M37 it’s backfiring a lot and wants to sputter out when I give is and throttle. Any suggestions.
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Backfiring
- Thread starter Carpartz88
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- 1,095
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- WOBURN. MA.
Carb needs to be rebuilt is a very likely cause for the problem if it has been sitting. I had a 51 M42 and went down the same road.
Mark
Mark
Carpartz88
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I just got it 2 weeks ago and it was recently rebuilt by the previous owner. He drove it 22 miles in 7 years. I got it and drove it 25 the first day. Now it’s not wanting to fire.
GopherHill
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You can do a search of past posts. Some have had exactly your problem. Good luck and have patience.
- 1,095
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Well you need to start doing some detective work. Pull the dist cap and check the points if good lube the shaft and set the points for .018". Next disconnect one of the spark plug wires and with a spare plug see it you are getting a hot spark (running) so you know the coil is ok. How long has the fuel been in the tank? Check the fuel filter to see if it is plugged up. I'm remembering from many years ago but there is a ballast resistor on the firewall and they can break or the connections can rust up. Dribble a little fuel down the carb while running the throttle cable by hand to see if you get an improvement. Baby steps.
Mark
Mark
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Likely rust particles are getting sucked out of the tank and fouling your fresh rebuilt carb.
- 1,095
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- WOBURN. MA.
Was just thinking the same thing. Truck sat and then started to be used and garbage from the tank makes a mess of things.
Mark
Carpartz88
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The in line fuel filter was a little gunky. Day 1 it ran good. Day 4 it was sputtering. Now it won’t start.
- 1,095
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- 113
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- WOBURN. MA.
Replace it and when you have it out try to blow through it. I'm sure it needs to be changed anyway and you can cross it off the list.
Mark
GopherHill
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Your gas tank has a drain plug to check on what's in tank besides gas.
GopherHill
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Look for "M37 acceleration " threads.
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Never was a "ballast resistor" on the firewall.
If the is a box inline with the distributor cable, it is a radio interference suppressor.
Those seldom give any trouble, and were only used on the very early production.
Just about every M37 out there has the newer distributor with the suppressor built in the power connector.
If the is a box inline with the distributor cable, it is a radio interference suppressor.
Those seldom give any trouble, and were only used on the very early production.
Just about every M37 out there has the newer distributor with the suppressor built in the power connector.
Carpartz88
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So I think I flooded it. Previous owner suggested I drain the oil due to gas in the oil. Is there anyway to just clean the oil filter instead of getting a new one
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No. The filter element is not expensive, NAPA has them.
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I doubt seriously that you could flood the motor bad enough to seriously contaminate the oil with gas. Try pulling the dipstick, wipe the oil on a rag (or be brave and wipe in on your hand) and smell it. Does it smell like gas? If so, maybe drain and replace the filter too. Shouldn't need to do that though to bring it back to life...
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Unless you had a stuck float or a needle and seat issue with the carb there is no way to dump enough gas into the oil to be noticeable. Any gas in the oil will go away as soon as the engine reaches temperature. I know I am dating myself but gasoline was once used to cut the old stright weight heavy oils to thin it out for cold weather operations.
Mark
Mark
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Where gas gets into the oil it means your stock fuel pump diaphragm has failed. Either age or the new gas eats it up.
This is why many, many have gone to an electric pump back by the gas by the gas tank to push the gas rather than pull it. This really cuts down on vapor locking as well.
This is why many, many have gone to an electric pump back by the gas by the gas tank to push the gas rather than pull it. This really cuts down on vapor locking as well.
John Mc
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That's a common failure mode for the stock fuel pump. It might not have crossed my mind for the symptoms you described, but if the previous owner is mentioning fuel in the oil, the pump diaphragm could be having problems.
- 1,095
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- 113
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- WOBURN. MA.
I was looking at the top of the motor but yep those diaphragms do fail.
Mark
Mark
Carpartz88
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So it was the ignition coil. Replaced that and it ran. For 20 minutes. Now it won’t start again.