hey guys i need help. i went form about 18 mpg to 8 what the hell happened, if you got any advice plewase fill me in

 

winter fuel or a possible vacuum leak

 

are your breaks dragging or even locked up? that is a huge jump. good luck.
chris

 

clogged exhaust, fouled plugs, bad wires.

you need to say more about truck to get any help.

 

i think i need new plugs but it shouldn't drop that far i have looked at many things but i am completely confused, what other info you need?

 

i assume it is a 4.9 90 f150...what trans do you have. what rear end? size tires....did you switch tire size recently. did anything happen differently than usual when ths mpg dropped. was it literally one day fine, next day bad? just give us a little background to give us an idea what we are working with. is your air cleaner clean? shouldn't effect it THAT much unless you filled it with cement.
chris

 

everything that 4.9inline6 said and:

when last tuneup? if plugs are fouled than that could be it, just change them, it is cheap to buy a set of motorcraft plugs for your truck. how many miles on truck? was it cold, raining? where you off road?

 

i don't know a whole lot about it i am a welder not a mechanic. i got 33's on it with a 4 speed with no overdrive which doesn't help i know. i don't know what rear end, it hasn't been running any different i just put in a new air cleaner. i don't think the plugs are all fouled but i know they are getting bad. if i tromp on iot real fast it chugs just a second then takes off

 

than take truck to a mechanic and have them look it over for you and at least tell you what they think is wrong and maybe then you can fix it yourself, or let them fix it for you.

 

If you haven't changed anything, look for a fuel leak.

 

You said in your last post,you just installed a new air cleaner. Did you mean a new air filter? If so, look for a vacumn hose that is loose or has fallen off the air cleaner. Maybe the air cleaner isn't on tight. I replaced the gasket on the top of the carb where the air cleaner sits and the condensation in my oil went away. Hope this helpes