hey guys. i have an 88 f150 xl 4x4 EFI 5 speed manual with a 4 in. lift and 33 in. tires, headers and aftermarket exhaust, but am getting terrible milage, about 8 mpg on the highway!! i have noticed that it is running VERY rich, exhast seems moist, does't idle well, etc, but i have no idea how to adjust the mixture on fuel injection. any ideas or pointers would be greatly appreciated. thanks in advance.

 

i belive EFI adjusts automatically via readings from the maf and o2 sensors. it is possible the maf could be dirty or you could have a bad o2 sensor.

 

I would agree with adam I would start with the maf and o2 sensors it is what adjusts everything automatically.

 

I believe that motor is a MAP vehicle and not a MAF. water is the natural byproduct of combustion. you should get steam of water out the tail pipe, not coolant though

 

have you ever got better than 8 as an average with that setup. it seams you were going for a bad a?? truck and not a fuel miser