2nd Gen Non-Engine/Transmission Poor MPG

[Jong]

I'm just starting to get some miles on my truck- bought it from Texas w/69000 miles on it. Immediately noticed the engine stumbling and missing occasionally under load, so I ordered a FASS kit and just got it on. Before, my trip computer said I was getting 16mpg on the highway, now I'm down to 13. 5 average. The truck is running better, but I don't know why the mileage dropped this much, the FASS kit is supposed to improve it!!!!! At 70 mph the tach is reading 1900 rpm and the converter seems locked. I'm also running 285/75R16's with a 3. 55 gear. Any ideas on what's going on here????

 

[The Adjuster]

Jong,



The only reliable way to check MPG is at the pump by hand (Miles driven / Gallons = MPG) ... the overhead consoles and fuel guages in our trucks are not known for accuracy.



My overhead says 20 - 22MPG but when I work it with a calculator I am only getting 18 - 19MPG.



MPG will vary slightly on each tank, some places will now have regular #2 and others will still have winter blend, I fuel at they same Petro truck stop here in Texas and my MPG are consistant within 1 MPG but if I fuel up at a different truck stop my MPG will change ... sometimes better and sometimes worse.



Work it out the old fashioned way ... it is the most reliable ... reset trip meter at each fuel up and work your MPG from the trip meter and gallons you put in.



Now repeat after me ... "The fuel gauge and overhead console in my truck are for decoration puposes ONLY" ... :-laf



Kevin

 

[rivercat]

fuel leak ?

 

[Jong]

Nope... checked the whole fuel system twice already for that.

 

[RAJohnson]

Clean and or replace the IAT sensor.

 

[silverram323]

Clean and or replace the IAT sensor.

been there, tried that.



I get 11-14 MPG ???/ I don't know whats the deal.



Jong, let me know if you figure it out.

thanks

 

[Jong]

been there, tried that.



I get 11-14 MPG ???/ I don't know whats the deal.



Jong, let me know if you figure it out.

thanks

yeah, i'm still working on it... i'd rather be burning #2 rather than midnight oil trying to fix it