stauby

im new on here, and i have a 86 f150 inline 6 4.9l carbeurated and im only getting 7 mpg. i am told i should be getting at least 14. my friends dad has one and hes getting 19. i have rebuilt the carb and put a new air filter on it, does anyone know y i might be getting crappy gas milelage and what i can do to fix it?

LiveFreeClimbHard

I had an old 82' F250 that got somewheres around....8 mpg's. It had all sorts of tranny problems. Vacuum hoses were always popping off keeping me in 1st gear. I actually found a transmission fluid hose ruptured and started sucking the ATF fluid into the engine. Once I got that fixed I think things were better, but it was honestly so long ago I can't remember for sure. Good luck!

joshtowal

Start with the most obvious. Look at your ignition system and work your way through combustion from there. If you have a CEL on, pull the codes and fix them in order. With mileage like that, I would expect at least one code. (***if it actually is supposed to get closer to what you said***) Once you've verified air, spark, and timing, check internals and do a compression and leak down test. After that, check your exhaust system.

DMC60

Make sure that the exhaust is flowing freely. Also a malfunctioning egr is a gas mileage killer, as is an 02 sensor. Get a book and tune it up and check everything over carefully.

Let us know what you find.