'91 4x4 using LOTS of gas. Any ideas?

[ron]

New here, thought I could get some info from you folks.
I have a '91 4x4 pu 22reFI and it has started getting verey poor gas milage. I have gone from about 300 miles a tankful to about 200 miles a tankful. This is what I have done so far: New O2 sensor (this was a computer code that I was getting),new plugs, wires, cap, rotor, air filter, fuel filter. Can find no gas leak, timing is dead on, no brakes sticking, no vacumm leak and the injectors seem to be hitting good (did the old screwdriver/stethoscope test on them). The truck still runs great and pretty smooth, doesn't have any big miss or anything, even at 170,000 mi. Just wonder if any one else has had this problem or if anyone has any knowledge they could shoot my way. Thanks guys, Ron

[wrnchplr]

New here, thought I could get some info from you folks.
I have a '91 4x4 pu 22reFI and it has started getting verey poor gas milage. I have gone from about 300 miles a tankful to about 200 miles a tankful. This is what I have done so far: New O2 sensor (this was a computer code that I was getting),new plugs, wires, cap, rotor, air filter, fuel filter. Can find no gas leak, timing is dead on, no brakes sticking, no vacumm leak and the injectors seem to be hitting good (did the old screwdriver/stethoscope test on them). The truck still runs great and pretty smooth, doesn't have any big miss or anything, even at 170,000 mi. Just wonder if any one else has had this problem or if anyone has any knowledge they could shoot my way. Thanks guys, Ron

how heavy is your foot? any changes like tires? have you checked the valve adjustment?

[ron]

Not a heavy foot. Have been very good about that. Have not checked valve adj. though. Thanks.

[22REkid]

I got an 86' that I can get about 180-200 miles to the tank, but I drive like my mom does so that explains that. It sounds like you have already done pretty much all the testing you can do. Have you checked the gas cap? When the gas cap clicks closed it seals off the fuel system. If the gas cap is malfunctioning, gas can evaporate into the atmosphere. Pull a cap off of another vehicle or just buy a new one. Valve adjustment doesn't have much to do with fuel consumption.

[KToy]

what plugs did you buy and what not.

i was told that the autozone plugs cause crappy gas milage.

as far as the rest of the tune up it sounds like you have checked it all out pretty well.

did you install a fuel filter yet ???

[wrnchplr]

. Valve adjustment doesn't have much to do with fuel consumption.

that is true but it never hurts to check. if the gas cap was bad you would also have a strong gas smell towards the rear of the truck.
you could also try this
http://www.wildyoats.com/hp_under_$95.htm