Diesel guys please help!

customjeepyj

customjeepyj

Member
Joined
Feb 12, 2011
Location
Trinity
I have a 2004.5 chevy 2500 duramax lly with ppe on 160 and ppe boost controller. The boost controller is always off. I drive very easy on the highway all the time. I can't get over 280 miles per full tank till the fuel light comes on. It did this during the summer and winter. I just ran a tank with diesel kleen by power service throught it and no change. My fuel filter is new and everyone else is getting like 400 + and I can barly get over half that. I have the egr block off plate, 4" exhaust and afe stage 2 intake. Towing my jeep it does not make much difference with the mpg. Any suggestions?
 
are you checking your gallons used? When my fuel light comes on in my 2004.5 I Still
have 14 gallons in the tank.
 
19.9 gallons at 280 miles = 14.07. 6 gallons left in there. still bad I just about to give up. the only thing I havent done is the pcv reroute, but a I dont think that will help with mpg.
 
Did the 04.5 trucks still have problems with leaky injectors? How about a sticky brake caliper?
 
there not suppose to. there internal instead of external now and it never smokes unless I get on it real hard but it does have a tuner on it.
 
Shawn said:
Did the 04.5 trucks still have problems with leaky injectors? How about a sticky brake caliper?
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customjeepyj said:
there not suppose to. there internal instead of external now and it never smokes unless I get on it real hard but it does have a tuner on it.
Click to expand...

this an LLY, with external injectors,

the LB7 had internal injectors with leakage ( among other ) problems If this were the case, you'd be spewing oil/fuel from under the truck.


Pull the programmer, see where the mileage goes from there. it is possible there is a problem with the programming.

stock wheels and tires ? proper recalibration for over sized ?
an error here would give false mileage figures as well.
 
Blkvoodoo said:
stock wheels and tires ? proper recalibration for over sized ?
an error here would give false mileage figures as well.
Click to expand...

Only by 5-10%. Unless he's got 40s on it, in which case I doubt he'd be asking questions about his terrible fuel economy. :lol:
 
I agree, but somethings causing it.

14 mpg isn't "bad" for a truck that size, but it should be better (16-18mpg with a light foot ).

the folks touting "400+ miles" per 19.9 gal used ( 20mpg ) are using new math or their figures are from the DIC on the dash ( which isn't all that accurate ) better to be calculated by hand.

maybe try adding just a little more boost to better use the fuel it is using ? Does this truck still have the variable vane turbo on it ? it's possible the vane position sensor isn't working properly, just not bad enough to throw a code.

What air filter are you using ? if using a K&N, throw it in the trash, put in NON OILED filter of your choice, then clean the MAF, clean the MAF anyway, just incase. a dirty MAF can cause issues like this.

this truck still have a catalytic converter ? have you been playing in the smoke a lot ? converter could be partially blocked.

without seeing live data ( Tech 2 or the like ) it's all guess work.
 
My buddy noticed his low fuel light was coming on early too. So he put a 5 gallon can of fuel in the bed and drove 134 miles till it ran out. So 280+134=414. He has a few mods on his truck also. Chip airbox straight exhaust
 
You do realize all GM trucks to 2007 have instrument cluster problems specifically the fuel gauge area, are you calculating milage by hand or using the cluster?? Dorman products sells a new dash available @ Advance auto.
 
I'm hand calculating and just removed afe stage 2 intake for stock one. Read that maf can be effected by aftermarket intakes. No smoke unless I giver her hell :). And yes it variable vein and I have PPE boost controller which seems to make mileage just a little worse. I have tried everything but the stock intake back on there. I bought it with it on there but he had a stage 2 afe so Ofcourse I put the aftermarket on there. Must of been the reason it was removed
 
The lly have an extremely small turbo inlet. This is the cause of the overheating problems and solved either with an AFE Bladerunner Mouthpiece or an LBZ Duramax Mouthpiece. Most/all that have switched have picked up a couple mpgs after the swap
 
When was the last time the fuel filter changed?

What are your driving habits? Keep the rpms unde 2000 will help on the mileage. I have had 2 Dmax's, the LB7 got 15 to 18. My LMM minus the DPF gets 16 to 20.

Try running a higher power level and keep your foot out of it :driver:

Most Of my customers typically see the best mileage on higher HP levels. Recently sold one customer an Edge Juice on a 05. He was getting 14-15 on the 60hp setting. Started getting closer to 20 mpg on the 100hp setting.

My $.02
 
Still a cr injection. Still prone for cracking, more so with increased rail pressure. Would check return and balance rates and verify no fuel contamination in the oil.

Sent from my DROID BIONIC using Tapatalk
 
(Not a thread jack but...)
Mine is a 2008 lmm CC DRW.
Hand calculated mpg is 12 unloaded....
8 mpg @ 24000# loaded.
So why does it suck so much fuel unloaded?
Bone stock, 60,000 miles and one owner.
Take me to school folks!
I wanna know about dpf delete and such.
 
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