accelerateing problems

[fultimerbob]

Hi New here trying to find out why my 2005 duramax is having problems.
I use it to tow my 5th wheel camper having no problem there but after disconecting I do a lot of back roading on dirt roads and after several hours of this I hit the main road and don't have power. I have to accelerate very slowly to get up to speed. It doesn't happen all the time. The air filter is good, the guage is in the green. I have been in a higher altitude than usual. The truck has 40,000 miles and I have already changed the fuel filter twice for the same problem even at lower altitudes. What can you suggest the problem is.:confused:

[Kennedy]

Adding lift supply could well extend the useful life of your filter(s) if they are indeed loading up. Here's how you can VERIFY the problem rather than guessing:

http://www.kennedydiesel.com/images/Dmax-fuel-filter-rest1.gif

[Mark Rinker]

Interesting - I have been noticing the same thing with my '05 LLY with 45K miles. Mileage has dropped, power is down.

Clean air and fuel filters. Haven't been running any fuel additives, maybe I have dirty injectors?

One noticeable change is the truck is now very quiet, even under load. Hardly any rattle like the LB7's.

[fultimerbob]

Hi Again
I stoped at A dealer to day an talked to them about truck an the teck is also doing the same thing I'm doing here in Moab,utah an we discused what I was doing and he said that i should run in a lowe gear an keep up my R.P.Ms so my engine wont load up so I'm going to try this an see.
He said that he is sure that it is just loading up.
fultimer bob

[Mark Rinker]

Ummm...that might be good advice...if you had a mid 70s big block under the hood with too tall tires and over-carb'd! As far as I know, there is no way for a stock Duramax to 'load up'. That happens to gas engines when the spark plugs get wet from too rich air/fuel and lugging the engine.

My '05 LLY truck is making a miserable 11mpg - loaded or unloaded - after 45K miles of 11 loaded (~10K avg), 15 unloaded (towing empty 4K# trailer home) for an overall average of 13.

I am thinking bad injector(s) and plan to have it into the dealer prontoi if a few bottles of treatment doesn't clear things up. Its not 'making oil' - yet.

[DmaxMaverick]

Loading up? You bet....but not what you're thinking. It can't load up like a gasser (that tech is full of it, and was looking for an easy answer).

Excessive soot can build up on the turbine (and vane, on an LLY+), creating turbulence and increasing the mass of the turbine. It doesn't take much to start bleeding off power, but the amount is so small you'll likely not notice. If you are having a noticeable amount of power loss, there is a lot more wrong than excess soot. Mine will do it, too, and I attribute it to a learning computer. If you drive lazy for a while, the computer gets lazy. A short episode of teenage flashback driving usually cures it, but not because I'm "blowing anything out".

Keep in mind....With our modern Diesels, more aggressive driving produces more soot, and that increases exponentially with power adders.

[Kennedy]

My '05 LLY truck is making a miserable 11mpg - loaded or unloaded - after 45K miles of 11 loaded (~10K avg), 15 unloaded (towing empty 4K# trailer home) for an overall average of 13.



We can take care of that.

I just knocked down 14mpg going and 13mpg coming with my 2005 towing my 2002 on my car trailer...

[rob from bc canada]

My 05 has only about 10,000 on it now - no noticeable lack of power or mileage yet.

However, given there were two people mentioning same symptoms at around 45,000, I'd be curious what fix you have in mind???

[DalesWS6]

On a recent trip to atlanta towing my 34' Campmaster with car inside my truck all of a sudden shuddered and rpm dropped way down. I stopped and cranked it up but it had hardly any power at all, at least not enough to pull my trailer anywhere. I had the whole rig towed in and they found the injector control module had failed. On the trip to atlanta i was getting around 11.2-11.4 mpg after the dealer fixed it I only got about 9 mpg on the way home and I have noticed that I have lost 2 mpg overall loaded or unloaded. I carried it to the dealer today and they scanned it and said there were no codes stored. He suggested that the latest software was probably loaded in and the new tune won't give the mileage that the old one would did. Has anyone heard of anything like this before? If so let me know what to suggest to the dealership to correct this issue. Any help would be greatly appreciated. By the way my truck has 31,000 miles on it. Thanks

[beeler]

Dale my memory is getting bad but if the injector control module is the one that is cooled by fuel my buddy had the same expeience on a 03. He lost milage but gained perfomance with the replacement. Don't know if he ever figured it out.