[dieselpusher]

Original owner of my beloved 2005 2500HD LLY. Truck has 165,000 miles. Household use, maybe 8,000 miles towing.
I'm not a diesel mechanic, though I can rebuild British carbs pretty well.

Two issues:
For years, it has had an intermittent turbo lag. No boost when accelerating, for several seconds, then it catches, and runs right up to normal boost. (Seems like about 29 lb is max.) Would like to solve this, as it can be pretty inconvenient to try to accelerate from a stop with no boost.

Recently, I started it and got about a mile down the road when it suddenly lost power (limp mode?) and ran quite rough/"knocking". Got it home. Had it towed to an independent "diesel shop". They diagnosed it to be needing all eight fuel injectors, to the tune of about $7,000. I towed it home, As I just couldn't put that much into it right then. Since then, I've started it a few times. Seems to run fine, then after a mile or so goes limp again & rough running. When it is running well, it;s like when it was new. Absolutely fine.

I do need to use the truck, so if we're sure the injectors will fix it, I'll have that done. I really don't want to spend $7,000 and still have a problem though. I have the diagnosis sheet from shop if that helps.

Thanks,
Ed

 

[scottydl]

Second opinions are always valuable, especially when it comes to high dollar repairs. You could call around with the current shop’s diagnosis and at least get some estimates… also look at sourcing the injectors yourself if a shop will allow, because they almost always have a markup on parts.

 

[OkDually]

Original owner of my beloved 2005 2500HD LLY. Truck has 165,000 miles. Household use, maybe 8,000 miles towing.
I'm not a diesel mechanic, though I can rebuild British carbs pretty well.

Two issues:
For years, it has had an intermittent turbo lag. No boost when accelerating, for several seconds, then it catches, and runs right up to normal boost. (Seems like about 29 lb is max.) Would like to solve this, as it can be pretty inconvenient to try to accelerate from a stop with no boost.

Recently, I started it and got about a mile down the road when it suddenly lost power (limp mode?) and ran quite rough/"knocking". Got it home. Had it towed to an independent "diesel shop". They diagnosed it to be needing all eight fuel injectors, to the tune of about $7,000. I towed it home, As I just couldn't put that much into it right then. Since then, I've started it a few times. Seems to run fine, then after a mile or so goes limp again & rough running. When it is running well, it;s like when it was new. Absolutely fine.

I do need to use the truck, so if we're sure the injectors will fix it, I'll have that done. I really don't want to spend $7,000 and still have a problem though. I have the diagnosis sheet from shop if that helps.

Thanks,
Ed

Welcome back

Have you checked for any codes? If so please post them here.
When it runs rough have you tried the icepick trick on the Injector harness? If not, that's where I would start

The Duramax is known for wire harness issues.
If you use the community search feature you can look up the Icepick trick and start diagnosing things

 

[heymccall]

You only need the ice pick trick if there are injector codes. Otherwise, don't ice pick.
Just changed the #8 connector on my '04.5 c4500.
And only pick or change pigtail on the cylinder that codes.

 

[dieselpusher]

There are injector codes on four. 2,3,5 & 8. "Injector Control circuit"
Also P2149: Injector positive control circuit- Group 2

We'll try the icepick method first...

Thanks...

 

[heymccall]

On my '04.5, it ended up being number 8. Clear the codes. Short drive and check again.

As an aside, many of the newer pigtail connectors have a wide contact in each position vs OEM having split contacts in each position. At least on the Napa ones.

 

[new2deez]

On my '04.5, it ended up being number 8. Clear the codes. Short drive and check again.

As an aside, many of the newer pigtail connectors have a wide contact in each position vs OEM having split contacts in each position. At least on the Napa ones.

On mine, code P2149 was the FICM. Good luck

 

[hihosilver]

just wrote this on another thread, mine would go into limp after hitting pot hole or whatever to shake truck ice picked then new plug ins then finally after not being able to find new harness had a shop make a new harness so far ( 8 months 5,ooo miles) no more issues, hope it solves it permanent