F**d faster than my Duramax.

[rcarbs]

My friends 04 PS 6.0 is faster than my Duramax. My 03 Duramax sputters at 80 mph, like its starving for fuel, by 85 its falling on its face. His PS runs smooth up to 85 or so.... Are all Duramax's like this? If not what can I do to fix it, If so, PSD here I go...

[HD-Nate]

Then there is a problem with your Dmax, like clogged fuel filter. Have your pedal checked to see if its reading 100% when floored.

Juice or not, I have never had a PSD 6.0 stay with me all the way up to 90 mph, never.

[saywhat]

My engine starts to fall off at 95 mph.From 60 to 90 it usually is a rocket or feels so in a passing situation.Maybe the fuel filter.I gotta start behaving or this truck and me are gonna get in trouble with the law.Havent had a ticket since 1988.Just turned 52 maybe that will slow me down(not)!Heading up to Sault Ste.Marie,Ontario on Friday,promise to slow down and get some really good mileage out of the beast.

[Johnny Diesel]

Sputters at 80?? Uhhh... theres something wrong your truck. Even before I juiced my 2003 I always cruised at 75-80+ and tipped up to close to 90 quite a few times with no problem. Pulls like a locomotive on steroids.

[Jomar]

With the Pred. set at 85hp,my truck will hit 96mph before I realize it. Don`t care about fooling around with the speed limiter. I haven`t run it up this fast very many times but it will do it every time.

Jomar

[crafty]

Saywhat,

Good travelling on your trip to the SOO. The forcast is for rain till the 25th and then some snow but not too much. I was up in the Soo this past summer. Very nice country up there. It was about a 7 hour drive for me.
Have a great Christmas. :D :D :D

[Jorday]

So stock Dmax auto vs stock ford 6.0 auto the duramax will win in a race, like a 1/4 mile race? And I mean stock, too. No chips or exhaust or anything.

[max out]

Hate to say it but it probley would out run the D/A beings it has a bit more HP and Torque, Now if the Ford has a crank case full of diesle there might be a differnt outcome, LOL

[schnier]

You have a definite problem, mine pulls best from 75mph to 95mph because you can floor it at this speed and it will not downshift. Now if you run a Predator or Juice up here look out because it pulls like no other thing I can describe, with or without a trailer. I promise I will never go back to a gas truck for any reason!!!!! Get it checked out at the dealer to see if there is a restriction somewhere. Quick.

[rcarbs]

Filter changed every 7500 mi, dealer said that without any codes he cant fix it. I guess I stuck with a poor running Duramax.

[Jomar]

rcarbs, give dmaxallitech a shout. I`d be willing to bet he can help. You definitely have a problem.

[HD-Nate]

Originally posted by rcarbs:
Filter changed every 7500 mi, dealer said that without any codes he cant fix it. I guess I stuck with a poor running Duramax. CODES......dont need no stinking codes tongue.gif

What ever happened to a good old fashioned test drive??? Take him or better yet their best Diesel man for a ride. SHOW him what it is doing.

If he cant fix it without codes it sounds like he is incompetent and you need to find another dealer.

Try to find a GMC truck dealer who only deals in TRUCKS. We have one here in town and many Bowtie owners bring their Dmax

[Ira Chandler]

Mine flies up to about 100 stock, no hesitation. I use the local GMC Medium duty truck dealer (Carl Black GMC, Kennesaw GA) and their service is excellent. This is the smallest diesel they work on.

[Spartus]

I would start with changing out both the AIR filter and FUEL filter...

[rcarbs]

Last fuel and air filter at 15000, problem still there. I think it must be some type of computer controlled problem. I am going to try a different dealer and see what they say.

[MICKD]

I have an 03 and pulled a 25' TT at 95 mph without a problem. Have it checked out man!!! dmaxallitech is the man to talk to.

[driller37]

You definetly must have a problem, mine has tons of power from 0 to 100, mine is stock with 50,000 miles on odometer, good luck on getting yours fixed

[Kennedy]

At 70mph in Interstate traffic, I pass people like them ricers in the Fast/Furious movies when they push the NOS button! :eek:

And to top it off, 18.85mpg last tank on winter fuel...

I'd look and see how oily your MAF sensor is. A lot of dealers condemn the sensor when oily, but a quick cleaning should cover it.

Also, check the dirty side of your air filter and be sure that the foil insulation from the inner fender is not sucked up inside. Filter minder should also tell a tale if there is a major problem...

[Dave Lewis]

I just don't see the power in the stock configuration like eveybody says they have. It does pull nice around 40 MPH but passing on the highway its no speed demon. Of course maybe its also because mine is a 3500 CC and weighs more. I'm cleaning my MAF today to see if it makes a difference. Of course the juice I ordered yesterday should help a little right :D :D ?

[Kennedy]

Originally posted by Dave Lewis:
Of course the juice I ordered yesterday should help a little right :D :D ? That is the key my friend! Mail man should have it to you Wednesday...