I pulled my camper(19ft)on a hunting trip.12mpg It took everything the truck had to pull steep hills.Felt like I was driving into a head wind.Making the power but not going anywhere.Not much better unloaded.13mpg So I had to come home and just left the camper there for now.Before I left I backed the fuel screw back out some.Tank home was better.16mpg.I can here my turbo alot more now but seems like it still struggles pulling hills.I bumped the timing a 1/16th before I left pulling the camper.That helped my cranking issue.
Okay heres the ?When I took the collar off the fuel screw I couldn't tell how far I turned it. The collar fits like a puzzle.Where the male end fit to the female left a place in the threads.Thats how far I turned it.The exhaust was rich.Would burn your eyes.Was I just dumping to much fuel to it?Should I back the screw off some more or bump the timing some more?I used to get 16mpg or better pulling this camper and around 20 on highway unloaded.I've also tried my best to check for air leaks.Wanna's been helping me and thanks.Thought I would give him a break.EGT are good around 1000 when pulling the camper on steep grade.Thanks for any help.Had tranny serviced before the trip too.Everything was ok there.

 

A cut fuel pin and afc spring adjustment,dose a bunch for mileage. I found the best set up for mileage is, stock or mild injectors and 2 to 3 turns of fuel. Take the pump all the way to head as far as it will go for timing, An a quick spooling housing for the turbo a 12 cm waste gated work's nice. Get rid of the lag! Adjust the afc housing thats where most of the mileage is. Good luck

 

Even though you had the tranny serviced before your trip, you might not be getting all your power to your rear wheels. You might check out your torque converter. Do you have a tach?? If not , did it sound like your rpm's were high but not going any faster?? If your tc is slipping, and with the weight of that camper, you might be just spinning your tc, not your rear wheels.

Just my nickels worth

 

I have about the same set up as you do. Stock injectors, pump turned up to the max, some added timing. Pulling my other toy, 7000 pounds of boat, motor and trailer. It is a 12 foot high windsock. I feel as if I am over running the trans and/or the torque converter when I really push it. The engine is pulling harder than the drive train can keep up. I haven't run a mileage check while towing because all the trips are short, but I cannot seem to struggle much past 65 mph on flat ground. If I run 55 mph I have a lot less trouble. I am fairly confident that the torque converter is most of the blame in my case. I need to keep an eye on my trans temp in warm weather. I've seen 260* and decided to back off to let it cool. I'm working a lot of overtime right now so maybe a new T/C is in the immediate future. I'm thinking Hughes.

 

Be careful with pushing the pump to the head with a rig that pulls.......there will be a lot more heat on top of the piston that the pyro will not be telling you.

Full timing and a load(for a long time) could spell melted piston!

A 1/16 or 1/8 would be all that i would push the timing on a work truck!

Just looked, your's is an inter cooled truck.......1/8 bump should be OK.

Us, non inter cooled truck just create way to much heat before, it get to the piston!!!!

 

With my truck and my mods I pull 65-70mph every where uphill/ mountain, head wind it doesn't matter. Sounds like a trans issue

 

I think you have a trans issue as well.

Also times X2 on the pushing the pump too far to the head when towing/hauling, .

I did that on my truck, had it about 1/2" back from the head. Was fine till the slide in camper went on, then I couldn't even do 65MPH in warm weather without it over heating(water). Before that I pulled the camper and Jeep without it overheating. Had the timing pulled back to 15* and then it was ok with just the camper but with the Jeep it was still too hot, sooo back to 1/16" over stock it went and there it'll stay!

 

Trans temp was never a problem.I can hear my turbo working now untill I pull a grade.Then the engine drowns out the turbo.(does that make sense)I'm going to back the screw off some more.There is a guy hear in town that build t/c.Wish I could swing it.That will have to wait.Got to get fuel milage back to make the wife happy.I was wanting to upgrade to a larger camper.There is no way it would pull it like it is.My chevy with the 4.8 pulled it better and got the same mpg.

 

The motor will drown out the turbo when going up steep grades. If you have your truck floored while pulling these hills and only 1000* egt you could use more fuel (injectors). What gears in the rear. I would say upgrade to a 16cm exhaust housing and a set of mild injectors. Make sure your tranny is tight. Then you'll show those hills who's boss

 

Okay here.Let me see if I am reelling on what yall are reelling off.Even though i gained mpg by backing my fuel screw off.That is not the problem.The problem is my t/c cant handle the pump turned up.Pushing a whole lot more fuel than the truck can handle.The extra power I was making being lost in the t/c.A t/c just aint in the budget right now.I will be turning my pump back to stock today.Gained almosty a 100 miles to a tank by backing the fuel screw off.I loved the power I was making with the pump turned up.But with diesel @ 2.50 a gallon.I'd rather have the best mpg rig I can.I read were alot of folks do mods and dont see a big mpg loss.Is my truck one of those that just doesn't respond well to inj pump tweaks.As you may tell my thick skull aint taking in this t/c thing.

 

When I turned up my pump I lost MPG too. Turning up the pump allows you to inject more fuel, if you keep your foot out of it and pulled hills and accelerated at the same pace as before you turned up the pump you would get teh same milage. But then whats the point of turning up the pump? Its your right foot using the extra fuel thats dropping the milage not the tranny.

Changing out to a more effiecent TC brought back most of my milage while letting my maintain my "spirited" driving style.