worseening fuel economy

[steelwill]

i have 02 e350 box van. new got 17 mpg,at 60000 went to 12.69, at144000
dropped to 9.83 mpg
help!!!!!!!!!!!!!!
pretty soon driving horse and buggy

 

[fgtex]

Has the fuel filter been changed every 10k to 15k miles?

fgtex

 

[SprintRacer26]

could be many things. fuel filter, air filter, cps, weak fuel pump, etc.

Have you checked to see if any codes have been tripped.

 

[steelwill]

worsening fuel economy

how do i ck week fuel pump/ cps ?

 

[JLDickmon]

was it a slow decrease or did it take sudden dramatic drops?

I'd be looking for a few things... first of all, what grade oil are you using (API service grade) ?

second, have it scanned for codes, pay attention to MAP/BARO codes, if you have it scanned with an actual DIAG tool, rather than a code reader, look at the data from the sensors...

3rd, look under the hood and tell us if you see an oily slime at the boots on the turbo plumbing...

finally, can't count out driver habits