mileage went south

[Dav]

my 88 2.9 auto was getting near 17 mpg at one point but now it is about 10 mpg
the truck constantly smells of gas but i can not find any leaks. i borrowed the 'noid tester' and it seems like all injectors are getting power
i changed the fuel filter yesterday because i have/had (i hope) an occaisional stumble at various speeds. also dumped a can of seafoam in the tank. haven't driven enough today to know if it helped.
what should i look at next?

 

[Paulos]

Have you pulled codes? How long since you changed the O2 sensor?

 

[Curious Hound]

Air filter? Pull fault codes? O2 sensors? you didn't change tire size, did you?

 

[RonD]

Check Vacuum hose on the FPR(fuel pressure regulator), if there is gasoline in it replace FPR

Return fuel line connected to FPR seen here: https://ww2-secure.justanswer.com/uploads/working4ev/2011-10-19_164557_untitled.jpg

Red arrow

Vacuum hose is in his fingers, unplugged

 

[Dav]

so far the only line that was loose goes from the front pass side of intake to air box. skeeters are out in force so anything else waits for tomorrow

 

[rusty ol ranger]

You got a bad FPR

 

[Dav]

and no codes showing up, although i'm not sure if they just light up or if i need to go to o'reilly's and have them hook something up

 

[Dirtman]

I really doubt oriellys would have the understanding or equipment to scan an 88'.

By this I mean the ability to count a blinking light, and a paperclip.

 

[Paulos]

I really doubt oriellys would have the understanding or equipment to scan an 88'.

By this I mean the ability to count a blinking light, and a paperclip.

@Dirtman
"Is reality confined to what is in principle perceptible only to the scences? "
scences? . I don't think my scences are perceiving the principle of the reality you speak of. .

 

[Curious Hound]

I really doubt oriellys would have the understanding or equipment to scan an 88'.

By this I mean the ability to count a blinking light, and a paperclip.

 

[rusty ol ranger]

Check Vacuum hose on the FPR(fuel pressure regulator), if there is gasoline in it replace FPR

Return fuel line connected to FPR seen here: https://ww2-secure.justanswer.com/uploads/working4ev/2011-10-19_164557_untitled.jpg

Red arrow

Vacuum hose is in his fingers, unplugged

Do this

 

[Dav]

I did have a slight gas smell in the vacuum line. changed the FPR. seems to have halted the stumble but not the gas smell.
finally found the fuel resorvoir is leaking at the gasket, only at above idle rpm's. tried to tighten the res. no go. but now it leaks a lot more. tried to unscrew the res. no go. but now it leaks even more than 5 minutes ago
thinking about junking the two pump system and putting a later pump in the tank.

 

[rusty ol ranger]

I did have a slight gas smell in the vacuum line. changed the FPR. seems to have halted the stumble but not the gas smell.
finally found the fuel resorvoir is leaking at the gasket, only at above idle rpm's. tried to tighten the res. no go. but now it leaks a lot more. tried to unscrew the res. no go. but now it leaks even more than 5 minutes ago
thinking about junking the two pump system and putting a later pump in the tank.

That resivior has a o ring in it. Thats probably whats leaking.

I know the o rings are available as my mechanic had to change mine. However, i believe you can also replace it with fuel line.

 

[RonD]

It should say "Do Not Remove" on the bottom cap, because its glued in place nothing inside, just a reservoir not a filter

The filter models did have an O-ring, and it could be replaced, if leaking, but not the reservoir models

Yes, long term replacing it with single pump setup would be best but..........................the fuel gauge OHMS changed in 1989, so a 1989(and up) pump setup will not work for your fuel gauge, so there are some complications that need to be addressed

If you can find a replacement reservoir it would be less trouble, Napa used to have thyem but not sure any more

Does yours have 2 hoses or 4 hoses?

 

[rusty ol ranger]

It should say "Do Not Remove" on the bottom cap, because its glued in place nothing inside, just a reservoir not a filter

The filter models did have an O-ring, and it could be replaced, if leaking, but not the reservoir models

Yes, long term replacing it with single pump setup would be best but..........................the fuel gauge OHMS changed in 1989, so a 1989(and up) pump setup will not work for your fuel gauge, so there are some complications that need to be addressed

If you can find a replacement reservoir it would be less trouble, Napa used to have thyem but not sure any more

Does yours have 2 hoses or 4 hoses?

Mine has a O ring and threaded cap but no filter....