Hi everyone,
looking to get some input...Can anyone tell me why my fuel mileage is down into the 6mpg? Thats what its saying on my dash, although im sure its fairly accurate because Im not getting anywhere near as far as before on a tank of fuel. Truck is serviced regularly. Thank you

 

What the coolant temp getting too?

 

Not sure the exact temperature, but its going up on the gauge like it normally does. I installed a coolant filter kit a couple months back. The low mpg was happening before I installed it.

 

How does it idle on a cold start? Any smoke out the tailpipe anytime?

 

When its cold out, its been blowing white smoke until it warms up.

 

I shoulda asked if you have any electronic diagnostic tools to work with. we need to see some numbers. There are a lot of possibilities but I suspect injector issues. FICM (Fuel Injection Control Module) voltages is where I'd start.

 

I tested the ficm with just the key on, it read 48 volts.

 

Live data is what is needed.
One quick way to get that is this tool

https://www.scangauge.com/products/scangauge-ii/

Then program in the Xguages for the Ford 6.0L PSD
https://www.scangauge.com/x-gauge-co...ncoln-mercury/


Here is a how to program Youtube.



Sean


6.0L Tech Folder

 

Is the oil level going up? Or coolant level?

 

how long do you idle?

 

Ouch..........the Cat powered semi I drive at part time gig does that good

 

First I'd manually check your mileage to be sure the gauge is correct.
Next, you really need some engine data as suggested.
Is your turbo spooling up? Any loss of power? Rough at startup? Last time you changed your fuel filters?
We need to see info with koeo and engine running? What's your Baro, ebp psi, MAP, etc. EGR?
Lots to evaluate on these engines.
Obviously speed and towing have some affect but 6 mpg is ridiculous.

 

Verify that the parking brake is off.
Could have a bad bulb.



Sean


6.0L Tech Folder

 

Possible dragging brakes.