I have a 1985 ford brono xlt 4x4 I have a manual transfer case, manual hubs 4 speed manual transmission and the I6 engine its old, has a manual choke and the dura spark brain it does have egr and a vacuum advance but its pretty much stripped of anything unnessasary no cats er anything I belive the engine is out of a 1980 f150 but the milage is so bad, is it the best im gonna do?

 

Welcome to FTE and the Big Bronco Forum. We will endeavor to get you the most accurate information we can muster.

I would tend to agree. Mileage should be a bit better than that especially in a 300. Have you checked your base timing.... without the advance and the engine already warm? Can we assume new plugs, wires, cap, rotor, etc? How is the carburetor for cleanliness and tuning? Clean fresh oil and filter? Unrestricted air cleaner (not filthy)? I'm just tossing all these things out there as potential issues that could contribute to the problem. You may have already thought of all of these things.

 

Many times bad mileage comes from the issues afore mentioned, also check the state of the sensors in the engine, usually such a bad mileage can come from that. How has been the engine behaving lately? do you feel it weaker?.

 

i dont know its rough it dosent have any sensors on it externally at least