im having the exact same problem with my 07, LP checks OK and rail pressure is fine, it just flat out defuels over 2000 rpm's, and the data logger confirms that, over 2000 the engine load % starts falling an is in the 20% load area by the time i hit 2700, and wont spinn any faster, im down to either a bad reading from the rail pressure sensor, or a miss-behaving ECU, will be swapping out ECU hopefully this weekend with a known good one

here is my thread----> https://www.dieseltruckresource.com/...d-t298851.html

 

All right, had the truck at Dan's Garage in Peckham, CO for a few days, hoping they might be able to track the problem down. They tell me the boost is where it should be, fuel pressure is good, but were unable to provide me any exact numbers.

They confirm I should be getting MUCH better than 12mpg, and the engine should feel much more responsive. HOWEVER, they say that the only way to be sure that nothing is wrong with my engine is to bring a trailer down to the shop and let them run the truck with the trailer hooked up and a scanner attached.

Am I wrong in thinking that full throttle is full throttle, whether or not you have a trailer attached? Truck is still gutless, taking its own sweet time getting up to 75mph on the interstate, and getting crap for mileage.

Still NO CODES..............

 

Forgot to add, the last thing they told me was, "put a programmer on it and it will be like it should, power and mileage-wise." as luck has it, they sell Smartys, etc, etc, etc. I was planning on putting a smarty Jr on it anyway, but just wanted it to run like it should STOCK first.....

 

My '03 used to pull 26k lbs on a daily basis and your engine is more powerful than mine and I had no problems getting going and up to speed. You definitely have someting wrong. Have they done volume tests from your LP and CP3? Other than that you're looking at injector issues!!!!

That truck should be seeing close to 20 mpg on the highway.

 

just signing up for this one..... carry on.

 

You stated it ran fine until a trip to Denver. Could this be an altitude problem? Denver is the mile high city after all.

 

Pulling a load will show more because it will come into boost sooner and stay higher. However, your little trailer is not a load!

 

Wow, ok. Things have been a little crazy for me with work the last couple of weeks, but I do have news on progress!

First of all, I just wanted to thank everyone who has taken the time out of their busy lives and schedules to look at my post about my truck's problem. Whoever says there ain't no decent people left should just try posting posting something about a problem with their pickup!

So, Dan's Garage had the truck for a couple more days, and I decided to have them adjust the valves, mainly because I do it on all our John Deeres on the farm on occasion, and didn't know if that had been done on my Dodge ever. Went back the next day, and found my pickup at the shop hooked up to the BIGGEST enclosed trailer I have ever seen that hasn't been a gooseneck. Mechanic says truck/trailer combo is 11,000lbs, and they have been doing engine load tests and further diagnostics, after setting the valves. They confirmed NO problems with the truck. 26psi boost at full load, rail pressure only 500psi under optimal pressure, and good power. Mechanic confirmed all the valves' lash was VERY out of spec.

Eager to test their diagnosis, I hopped in. SURE ENOUGH.....good power, pulled trailer in 6th gear 80mph at half throttle, with more to go! Unhooked trailer, paid the desk lady, and away I go.

WHAT A DIFFERENCE a valve adjustment made. Turbo spools a little quicker, mileage is up to about 15, and more low end torque. It felt like a new truck! I ran it around for about a week before ordering my Smarty Jr. from them, and got 'er programmed today.

HOLY COW......I can't believe it is the same truck! Smarty Jr. is just set on Fuel Economy mode with torque set at Default........jiminy crickets. If I'm not careful, tires will break loose in second coming off of stop lights..... One tire will chirp before my factory limited slip starts to compensate. Couldn't wait to calculate mileage, so drove it around until I had 60 or so miles on the clock, then filled it back up.

Guess what???? 20.6mpg!!!! Score!!! he he he. And that's with a slightly itchy throttle foot here and there! Not too bad for a 3/4-ton truck! Can't wait to see how light my landscape trailer feels back there!!

Thanks again for all the helpful insight everyone!

 

Urgh. Not sure if this is a problem, just remembered. While coasting down a hill at about 65mph, my little grid heater light came on....... And now it won't shut off. Just stays on all the time. I don't notice a change in power, or how the truck runs, just that light comes on even when the truck is warm. It started about 30 minutes after programming it with the Smarty Jr.

Has anyone had any similar issues?

 

And.....once again.......no codes! Just that **** wait to start light...... I don't notice the charge gauge being any higher than it normally is, I can't tell if the grid heater is staying on, or if it's just something in the Smarty programming that is making just the light come on? The truck has never thrown a code before, even through the low power spell it had. Just got a clean bill of health from the mechanic!

 

Ok, false alarm. Updated my Smarty Jr. and re-tuned the truck. No wait to start light, and runs like a champ. Thanks again for the help!!

 

happy for u ford! 1 thing however, they said u had 26 pounds of boost at full load? thats low for an 05. your boost should go to 34 lbs then settle at a solid 30lbs. unless they were lugging it a little, then it might read lower. i dont kno. mabye nothing, keep us posted on how its runnin!

 

Ok good to know Vaderpower, when I get some gauges I will check and see what boost is reading now with the smarty.