I may have diagnosed the problem with the 235. I believe it has a virus, and unfortunately it seems to be contagious. My 1960 Volvo now has the same symptoms. I fear the contagion has to do with the careless exchange of essential fluids.

Many of you directed my attention to the fuel system, so when I found rust particles in the fuel filter I decided it was time to treat the gas tank. So I emptied the fuel, it turned out to be holding almost half a tank. Every gas can I could find is now filled. Since the Volvo was running on empty I poured 5 gallons of my Chevy gas into the Volvo. It now exhibits all the same symptoms as my rebuilt 235 has had - poor idling, backfiring on deceleration, stalling.

Believe it or not I am glad to have a diagnoses. I've let gas sit in the tank over a winter many times without problems, this is the first time I am the victim of bad gas.

I am going ahead with the POR 15 treatment. Maybe I'll have a smooth running truck soon. I also hope to burn up as much as possible of the bad gas in the Volvo before refilling.

Karl

It may not be the easy way, but it is the Cowboy Way - Ranger Doug
Beware of the stories you read or tell; subtly, at night, beneath the waters of consciousness, they are altering your world. - Ben Okri
1953 Chevy 3100
1960 Volvo PV 544
1941 Chevrolet Special Deluxe