The truck has always done this 'dieseling' thing since I bought. Initially it had a Holly carb on it, and I bought a newer Holly after purchasing it years ago. While it ran better at that time, it still did the dieseling thing. The truck has sat for years until I brought it out of the yard late last year. On top of the dieseling, it would backfire out of the exhaust and ran like crap. I noticed a leak from the Holly on the intake manifold, so I replaced it with an Edlebrock as internet searches led me to that being a preferred carb. I also replaced the cap, rotor, wires, plugs, and set timing. After this point, I had taken the C65 to a truck shop where they changed out the older split rims with R22.5 wheels and tires. I asked them to look into the 'dieseling' and the shop owner came back with the possibility of valves and carbon build up as he couldn't get it to stop either. He said my timing was perfect. Idle speed is very low. I wish I could attach a video for you to hear it run. Supposedly the mileage is roughly 40k on a newer crate motor, but I can't verify that. It doesn't smoke or seem to burn oil. It's not running rich or lean, seems about right, in fact, with this Edelbrock carb, it runs better than I can member, I just have to pull the choke to stop it after I turn the key off or put it in gear.
I never heard of the 'Steam clean the valves' as Mike B suggested. I could get my wife to help me try that.
Last edited by BowtieJunkie; 04/05/2022 11:57 PM. Reason: Typos lol
