Absolute noob tuning problem...

[chevyburnout1]

So I think I've been in LB7 tuning land too long :rofl: I've tuned a few LBZ/LMM's but most were just deletes/turbo brakes. My noob question is: can you fully disable the P0087 limp mode on an LBZ?? I'm so used to tuning LB7's that I was under the impression you could disable it on all operating systems, but I seem to be having a drastic hard time on my buddies LBZ. Now I understand I'll get the "fix it correctly" responses and I can assure you we've done the tests. It's either injectors or a CP3 and it barely drops rail only under the most optimum conditions. The truck is just shy of 400k miles and it runs flawlessly so he is hesitant on dropping the coin. I've tried shutting off the code and changing the "pressure delta" table but that table always puts it in a ghost limp unless I have it set at 22.5mpa. I'm kinda at a lost. Any suggestions?

One other issue. I programmed a turbo brake into his truck as well and the damn thing will surge the turbo when slowing down around 2000rpms. It's the same tune setup I've ran in other trucks, yet his is the only truck that I've tuned that does it, so it caught me off guard. Even opening up the vanes drastically it still intermittently gets a slight surge.

The only thing different is his is a cab/chassis model. Any help will be greatly appreciated! Hopefully the heat has just fried me and I'm missing something obvious! When I get back home I can attach the tune if need be.

 

[chevyburnout1]

Was it that bad of a question? haha. I took the turbo brake tune out as even at 80% vane position it would still bark the turbo about twice slowing down. Yet I just tuned another LBZ yesterday with 95% vane position and it works just fine???

 

[malibu795]

Couple ways to do it... Raise fueling limit under defuel.. Deactivate limp by putting the low threshold down around idle rail

As for turbo brake I ran 100% when mine was VVT.. My issues where it would lock/stick the vanes close under load pulling a grade then downshift 5-4 and go from 30 to 50psi boost

 

[chevyburnout1]

Thank you sir! So far the fueling patch job is working, enough so that he is thinking about actually repairing the truck. The turbo brake issue isn't a big concern with him, it's more me that is wondering why it's doing it.

 

[Harbin_22]

I tried some things trying to get one to quit limping. It will only limp pulling a load after a couple hours and actual is just a little slow to catch desired. The delta thing happened to me too. I wish someone did have a way to make it go away. His trucks runs great other than towing his camper hours at a time

 

[JoshH]

You can kill limp mode.

 

[Harbin_22]

You can kill limp mode.

I think his truck still did something weird when it would happen. I can make it keep power but maybe the CEL would still come on and something else, just can't remember

 

[JoshH]

If it's an LMM, it may still say reduced engine power, but you should be able to keep the CEL off and keep it from dropping power.

 

[chevyburnout1]

I think his truck still did something weird when it would happen. I can make it keep power but maybe the CEL would still come on and something else, just can't remember

This is actually what my buddy wanted. To know it's still an issue to keep track of it, but not put the truck on the side of the road with a convoy of semi's on his ass.

Josh you wouldn't happen to have any input on the turbo brake barking issue?