LB7 limp mode

[dunndl7064]

Older Nam Vet here with some stupid questions. I have a 2001 Chevy 2500HD turbo diesel (145K miles) with issues. Normal driving is fine. But when pulling my 5th wheel uphill, if I step on it, ck eng light comes on, and it goes down to about 2000 rpm about 30mph with no pedal ....just wants to crawl. When I pull over, shut it down and wait 20-30 seconds and restart it is fine, until I again try to step on it again. (I can't yet check the codes till Wednesday.)
We have replaced the tank fuel filter, the air filter, the front end fuel filter. My mechanic seems to think it is the injectors...($3-4k) ouch...
I want to believe it might be collapsing rubber fuel lines....I am already bleeding on this....any ideas? Thank you in advance!

 

[TheBac]

Moved to LB7 section.

 

[clrussell]

What code with the check engine light?

 

[nubuilder]

Check codes.

My old LB7 did the exact same thing. Threw a code P0093 for "large fuel leak". The CP3 wasn't making the pressure the ECM was demanding, throwing the truck in limp mode and limiting it to 2,000rpm. If I shut the truck off, it would drive just fine until too much load/demand was put on it again. The first time this happened was towing a car up a slight hill at 60. It got worse to the point it would happen with just the truck going uphill. Flat land was fine.

Wasn't horrible to replace the CP3, just a bit frustrating and a tight area to work.

Sent from my SM-G930V using Tapatalk

 

[rfletes79]

At a glance I would say it’s your cp3 not keeping up. Keep in mind you will need injectors eventually, not saying they’re not contributing to your current issue. We need codes and live data info monitoring fuel rate/pressures to see what’s going on.

 

[2004LB7]

Try replacing all of the rubber fuel lines on the engine as that is cheap compared to injectors. It may be worth temporary using a clear hose post fuel filter to see if you are getting air in the fuel. Too much air and fuel pressure will drop

If the above doesn't solve it then time to do a return rate test on the CP3 and each bank of injectors

Also, codes set and injector balances rates would be nice to see

 

[dunndl7064]

Thank you all for the quick replies....I will have codes tomorrow afternoon....and I will see where that leaves me. I will post codes then....thanks again.