first breakdown was my bus conversion. driving though Wyoming and couldn't build air past 60 psi. compressor was shot. this time working on an AVCO with a 440 Dodge. starts and stalls starts and stalls no power when running as it stalls when you try to accelerate and found that the carburetor is cracked and loaded with varnish. Bus engine was blown as the mechanic said it would be okay to drive it to a service station. Compressor blew up inside sending all the coach air into the engine and blew off the liner's O-rings.
I am replacing the carburetor with a new one from Rock Auto. Hopefully the AVCO will run. I had a Superior with a 413H engine in it and driving it one day it was overheating and running badly. Points were bad and had to have the radiator boiled to get scale removed and then ran great and cool. one other time I was at a light and it stalled couldn't get it started and then i wiggled a wire in the battery box. Started right up. removed all the grounds cleaned them up with emery cloth and problem was fixed.
In my second bus I was driving it home from Maine to Mo in Illinois bus shut down and coasted to a stop tried everything and couldn't get power to start it. found a circuit breaker and reset it and was on my way.. few months later same thing happened and couldn't reset the breaker. breaker was bad replaced and no more problem. that is some of my experience. To all you bus converters and diesel pushers check that compressor they will go and can cause tons of serious issues.