Bad gass milage all of the sudden

[Yng_pnk]

On a full tank of gas i get less then 200 miles....... I donyt know if my gas gauge is proken and i can go more miles but i fill it up with 14-17 gallons each time. It runs great, i cleaned the MAS but still poor milage.

 

[Yng_pnk]

ANIT FREEZE PULLING DISAPPEARING ACT!

Im not over heating or anything, but about once a month my heater gets cold i check the anti freeze and there is nothing in there. I filled it up recently and let in run in my shop, but nothing went on the ground. Each night i park in a clean area but i dont see anythingin the floor , yet it seems to dissapear! My brother told me that it could be going out of my exaust? wouldnt it run like sh@! if it were the case? plus after it runs for a while all the condensation stops coming out of the tail pipe. any thoughts?

 

[aldive]

Have you run a code scan? Its possible that an O2 sensor has taken a dump on ya.

Good luck.....

 

[TPLYNCH]

Sounds like a bad head gasket to me....

 

[Yng_pnk]

the whole top half of my motor was rebuilt, woudl that include the head gasket? ANd how hard is the O2 sensor to replace and how much does it cost?

 

[Slick]

I had that same problem with sudden low mileage, and it ended up being my tranny about gone, i got a new rebuilt tranny under warranty, but it would have costed a bit over $2000. lets hope its not that!!

 

[Mike 92 XLT]

One of the common causes of bad gas mileage is the FPR (Fuel Pressure Regulator) going bad. Check the pressure at the Schraeder Valve on the passenger side fuel rail. Should be 35-40 PSI. When the regulators fail, the pressure shoots up to close to 90 PSI.

peace

Mike

 

[Yng_pnk]

thnks guys i appreciate it.

HAvent found out the cause, Ill post when i figure it out to let you know. Taking it appart this weekend

 

[Ross-N-Chicago]

The disappearing coolant could be the lower intake gasket. Do a search and you'll b overwhelmed like I was. I agree with the FPR and O2 sensor swap--about $90 for both and shouldn't take you over an hour with the Haynes or Chilton. That seems like a good place start. What other symptoms do you have??

 

[b]

What did you need to get repaired to increase your gas milage Yng_pnk?

Did you the codes pulled or the FPR tested?

Thanks

(This is an old thread, but topical during my search for information)

 

[Majisto]

One of the best ways to increase fuel economy is to perform a mod called "Do not redline engine at every light". It can cut down on excessive fuel consumption and will lead to much longer drivetrain life. I have it, and it works wonders. It has gotten me almost to 20 MPG in the city sometimes and mid 20s on the highway. Occasionally, the mod will fail, but I am quite please with it. Y'all should get one too.

 

[b]

Replaced the FPR recently...gas milage is back up to normal. I was running 170-210 miles to empty or 10-12 miles per gallon. Now back up to 16-18 mpg! At these gas prices, you got to do anything!!!

 

[Hokie]

Originally posted by Mike 92 XLT
One of the common causes of bad gas mileage is the FPR (Fuel Pressure Regulator) going bad. Check the pressure at the Schraeder Valve on the passenger side fuel rail. Should be 35-40 PSI. When the regulators fail, the pressure shoots up to close to 90 PSI.

peace

Mike

What kind of gauge do you use to measure this?

 

[Brandons]

I get alot of condensation when i start (water out the exhaust) i havent really tracked it down for how long it lasts, but it seems it will keep doing it over a half hour. Hearing about the antifreeze leaking out the exhaust has made me curious, and the water that comes out is almost black. Note, it is also winter here.