I have a truck I put a cam in for a friend. I have EFI live and had Blackbear do the tuning. They claim everything looks good, minus a potential vacuum leak. I checked everything and spayed all the potential leaks with either and no sign of a leak.

The problem is the truck often shuts off when coming down to an idle. It will do it sitting still but happens much more often when under a load like coming to a stop sign. We put a new 3200 stall in the truck along with headers and ORY. The cam is mid 230/230 range and it is a 5.3 truck.

Blackbear hasn't been very quick to respond when I email them so this has been going on for a good while now.

Does anyone have a simple idea of what I can adjust slightly to help when it comes down from higher RPMs the idle doesn't crash cause the truck to stall.

 

Ok, heres a dumb question! you sure its in the tune and not a sensor or something going bad? I had similar issue with my 02 avalanche would do same thing randomly, ended up being bad MAF, truck was stock but best tune in world wont make up for a bad part.

 

Are there any codes?

 

What year? DBC or DBW throttle body?

 

Bump up the idle airflow a little and or slow down the decay rate.

There are two idle airflow columns. One for park and neutral and one for in gear. Bump both of them up a little, and it will fix your problem.

 

Maybe, post a log of the issue?

 

Ok Gadgetized. I was figuring something along those lines but didn't know what or where it would be call. I will see if we can get that handled.

 

I had a similar issue in my 99 now that i reread the original post, where it would idle down really low and shut off if i came to stop or came back to idle too quick in drive. It turned out the torque management was kicking in and retarding the timing something like 15-20* but only in d,3,and 1. park, neutral, reverse and second gear the idle was fine. When it got tuned he says he tuned torque management out completely and that fixed it, said something in the harness was doing it. I figured ot had more to do with idle tables, id rather be able to find and fix the problem if in fact there is one...