Extremely Bad Gas Mileage

[Beastly88]

I have a 88' 2.9l 5spd and i just filled it the other day (should be 17 Gallons) and i hit the trip with it was down on E today and the trip only said 120 miles that cant be right and when i hold the gas nozzle wide open it squits it back up the tube like its half block or something ...what could be the cause of the fuel mileage i have a heavy foot but not that heavy

Thanks
Justin

 

[holyford86]

pull codes, instructions in the tech library. Are you leaking gas?

 

[Jspafford]

My 89 has a 23 gallon tank and I regulary get over 300 miles out of it before it gets to 1/4.

Any black smoke from tailpipe? Does it smell funny? If it's burning that rich you should notice.

 

[Beastly88]

no leaking, and no funny smells that i notice and no smoke...

 

[QNev]

Bad spark plugs?

 

[Beastly88]

just replaced the plugs and wires and was gonna change cap and rotor but i cant get the old cap off..the screws were put in too tight

 

[Beastly88]

got the cap and rotor changed lets see if this works.....will plugged cats contribute to it or any loss of power.... first thing ive owned with cats.. lol

 

[IMenriched]

got the cap and rotor changed lets see if this works.....will plugged cats contribute to it or any loss of power.... first thing ive owned with cats.. lol

They sure can...
but ussualy if the cats go bad it is a result of something else...prolonged issue with fualty sensor or sensors or road debris that smacked it jarring loose the internal stuff for example.

drive it for a bit at night 10-20min...shut it off and kill the lights....look under the truck at the catalitic coverter...if it is glowing at all...it done. Then it has a pretty good restriction.


now your gas tank sending unit might...probably... is fualty. mine is like that....about 120mile and its dipping on E....but...when I fill up, I'm only putting in 8 or gal. & its full. SO I had roughly 1/2 tank left. I just watch the trip odometer closer when it appears to be low.

pulling codes will help zero in on what sensor or sensors that could be giving you fits also

 

[Cyberbeer]

Check the Fuel pressure regulator. Pull the vacuum line off of it and look for gas spilling out. If gas comes out replace regulator...was 36 bux at my local autostoner

 

[Beastly88]

thanks guys i will check them today...

 

[BroncoDan]

when is the last time you replaced your fuel filter? easy and cheap is where i would go first... i swapped mine out and i went from 240miles/tank to 300miles/tank... not bad for a $10 fix...

 

[BlackBII]

If that cat is glowiong at all, it is just doing it's job.

A simple vaccuum test will let you know if you have a clogged cat.

Did you ever get the codes pulled?

 

[Beastly88]

no i havent pulled any codes yet...ill have to take it somewhere for that

 

[Beastly88]

Anyone wanna give me a general location of the filter so i can go right to it ....and will a brand new fuel filter for a 94 f150 work i bought the filter and before i got it installed the truck died...

 

[BlackBII]

The F150 filter probably won't work.

The filter will be on the driverside framerail, right under the drivers seat.

Pulling codes is easy, don't need to take it somehwere. Looky here.
http://www.therangerstation.com/tech_library/OBD_I.html