lb7 help ?

[Dmax0372]

Hi i have a 03 duramax that has a bad power loss while towing up hills I can only get 55 maybe 60 out of it and I only have a 22foot trailer .so far I have dumped 5 g in it new turbo new injectors new egr cooler new glow plugs new banks big head waste gate and have ben told the balance rates are great and no check engine lights please help thanks

 

[kiwilml]

Well how much weight and how steep of hills are u pulling and do you have it tuned?
A little more info might help, it may be doing like supposed to be..

Can you feel the truck quit pulling as good or what?

 

[Dmax0372]

The trailer is only around 10 thousand pounds and I can barely feal it pull at first then it flattens out and I have my foot to the floor and yes I have a custom tune made for the truck

 

[chevyburnout1]

Responded to your other thread but was not aware of the custom tune. More than likely your dropping fuel pressure but the custom tune is preventing any code from setting. You need access to a very quality scan tool for us to help you out before you throw more parts at it.

 

[Dmax0372]

If I had low fuel pressure wouldnt the fuel rail pressure sensor catch that caue before I had the custom tune made I had the edge programer and I still had the same problem and still with no low rail presseure code

 

[1ATony]

Thanks for joining
Tony :hello:

 

[chevyburnout1]

If I had low fuel pressure wouldnt the fuel rail pressure sensor catch that caue before I had the custom tune made I had the edge programer and I still had the same problem and still with no low rail presseure code

Depending on the programmer it may have covered that up as well. Regardless we need to see some ECM data at full throttle. Preferably the commanded mm3 and rail pressure. Even if it involves a $100 diag fee from a quality shop. That's a lot better than throwing thousands of dollars at it. Without that we can only offer so much help.

 

[Dmax0372]

Thanks at this point I have it at a dyno shop to be run under a load to be logged and then they van tell me if its a lack of fuel under a load

 

[Dmax0372]

Say I have a question for u with my truck I have the 50amp fuse gor the pas front and rear window and the driver seat keep blowing . I have read about a wire by the parking break grounding what is your take on that

 

[chevyburnout1]

Perfect. That's exactly how my shop is. Nothing like a being under the hood at full load :woott:

 

[Dmax0372]

What about my electrical issues above

 

[chevyburnout1]

I don't have any common failures stuck in my memory. Have never had any of those major fuses blow.

 

[MechanicalReign]

This might be silly question. Is there an lift pump on your truck