bkay

Talked to one of the local dealers (good dealer by the way) about fuel milage drop that I have had. He said that it could be caused by the MAP/Boost sensor. It could be under fueling or over fueling either way he said it would effect the fuel milage. Does the MAP sensor actually work when the EZ is plugged in? Can it still give a wrong reading? My fuel milage is the same with or without it plugged in. Had RV275 pulled them also thinking they had changed the fuel milage. Have checked for boost leaks, retorqued and retightened anything having to do with the boost side. Still getting 15.5 mpg. Use to get 20.5 on the interstate and 17.5 mix driving. The only way I know to check the MAP is to take it in for a scan $$$$. Also he told me it could be injector problem. I'll rule that out because the injectors have been changed with out a fuel milage change. Also I have checked and changed the IAT sensor the old one was giving a different resistance read than the new one (not much but it was different), and for $18.00 and the old one was already out. Somebody has to have an idea what I could do.

hellotbone

I dunno mine has always gotten better mileage with mods not worse

Mathew

On a diesel, under or over fueling is simply the throttle control (more fuel = more power, less fuel = less power) - so I don't think that would change mileage. Perhaps the injection timing is slightly altered based on boost but I don't think that would be the amount of change you are describing. <br><br>I find that driving conditions and fuel make the biggest difference. Headwinds cause big changes at highway speeds. Cold weather driving on shorter trips where things aren't warmed up costs mileage. Winter blended diesel is significant as well. Did you fill up at the same station with the truck level?<br><br>Those are some ideas anyway.<br><br>Mathew

danlit

How long have you had the truck. Is this your 1st winter w/it<br>Winter blend &amp; cold aren`t good for mileage.<br>Put the EZ back on.and wait till it warms up.<br>With my mods I get about 20~21 Hwy 17~19 city in warm weather, Now 17 Hwy 14~15 City<br> Danny

Homestead

I've noticed some drastic mileage changes depending on who's fuel i'm using. Some are better than others! My mileage went up when I had my EZ installed.

rich

Sometimes if your lift pump is going you will experience a drop in mileage and power

bkay

Should have said that fuel pressures are good 15psi at idle, 13 ar cruising speed. 25 miles to work one way, 24 of those are highway. Fill up at one of two stations consistently. Fourth winter to own the truck. I thought the same thing about the over fueling and under fueling but I can't out think these stinking computers. ??? ??? [undecided] [undecided] Also I give the engine five to ten minutes to warm up before driving, longer when colder and the heater plugged in(it is 63 degrees here this morning)