1
1978BroncoCustom
Guest
Good evening all.
My '78 Bronco has the factory 400M engine installed and blows out a small amount of black soot on first startup of the day; can be seen on the concrete of my drive way. Prior to my purchase, the Bronco had set up for quite a few years so there could be quite a bit of particle buildup in the intake, valves, pistons, etc. I don't think it is the exhaust as I had it completely replaced during the partial refurbish. My Dad and I reset the carburetor and idle speed per factory instructions after I replaced the spark plugs, plug wires, coil and ignition module earlier this year; is it possible we have it set too rich? A third and final theory is the 10% by volume enthanol gas mix I have been running in it doesn't burn very well and is leaving some fuel residue in the pipes when I turn the engine off. Would running a higher octane ethanol free fuel fix it?
The engine starts well on cold mornings, doesn't smoke or use oil (107,000 original miles when purchased) and idles well once it gets warm. Any recommendations or information would be greatly appreciated.
v/r
Jim Meek
My '78 Bronco has the factory 400M engine installed and blows out a small amount of black soot on first startup of the day; can be seen on the concrete of my drive way. Prior to my purchase, the Bronco had set up for quite a few years so there could be quite a bit of particle buildup in the intake, valves, pistons, etc. I don't think it is the exhaust as I had it completely replaced during the partial refurbish. My Dad and I reset the carburetor and idle speed per factory instructions after I replaced the spark plugs, plug wires, coil and ignition module earlier this year; is it possible we have it set too rich? A third and final theory is the 10% by volume enthanol gas mix I have been running in it doesn't burn very well and is leaving some fuel residue in the pipes when I turn the engine off. Would running a higher octane ethanol free fuel fix it?
The engine starts well on cold mornings, doesn't smoke or use oil (107,000 original miles when purchased) and idles well once it gets warm. Any recommendations or information would be greatly appreciated.
v/r
Jim Meek