Why the crappy mileage?

[nucleardog]

It's a 87 XLT ex. cab 4x4 with the 2.9l motor and A4LD transmission. The truck runs good has a 5 month old rebuilt transmission that shifts good. I don't abuse the truck or run it hard,

The truck is getting about 100 miles per tankful!!! What is wrong with this thing? Like I say it runs and shifts good. It has 145k miles on it it doesn't burn oil, though the engine is no powerhouse it runs good...Help...

 

[Spitfire1975]

running rich.

Pull codes. Probably going to be a bad O2 sensor or Coolant Temperature sensor, but you didn't give a whole lot of info on it. The tech section will have the information you need to pull the codes.

 

[jhammel85]

I agree with Spitfire 100%. If either of those are gone, your computer could be fooled into dumping massive amounts of fuel in the cyls.

Also, have you checked the Fuel Pressure Regulator? After running the truck, pull the back vacuum hose and check for raw gas.

 

[Spitfire1975]

I always forget about the FPR. My bad. Definitely check that.

 

[BlackBII]

How do you know your tank is really empty when its on E?

RBV's are known for their inaccurate fuel gauges...

You need to figure out Miles per Gallon, not Miles per Tank

 

[nucleardog]

The FPR checks out ok. The O2 sensor was already replaced. Have not checked the ECT at this time.

 

[Spitfire1975]

When was the O2 replaced? Just because it is fairly new doesn't mean it is good.

 

[2ndgen]

have you checked the TPS mines getting about 150MPG and the guys at oreillys said it could be the TPS also when i pull the code it spits out a 77 operator during dynamic response test /wide open throttle not sensed

but i know that i did that part of the testing while pulling the code
so the TPS is not registering.

getting my new one on friday..

 

[Spitfire1975]

Wish I was getting 150 MPG's.

 

[disciplerocks]

Wish I was getting 150 MPG's.

roflmao me too!

 

[2ndgen]

ment per tank

 

[Big Jim M]

Pretty crappy post! 100 miles per tankfull??? What the hell does that mean? Milage is judged by MPG.. not by MPT! So fill it and drive it and then fill it again and see how many miles hou have driven and how many gallons you used.
I don't understand how the above posters could give ANY ADVICE not even knowing if you have a problem or NOT!
Big JIm

 

[RustedRanger]

I think if you pay attention to how far it goes after getting gas and you drive something enough then you can tell if the mpg's are sucking,not exactly but close.

 

[Spitfire1975]

Besides BlackBII ALREADY told him to check MPG's, not MPT's.