Closed loop issue with boost

[Jwoodman]

Hey guys. I've got a 03 Silverado 1500hd with the 6.0 and 4L80e. It has a single turbo on3 kit on it. Its got a 2 bar Speed Density OS. I've gotten the tune pretty happy in Open Loop. When enable closed loop again, the truck goes lean in boost under moderate throttle. This doesn't happen in open loop only. I've got Boost Enrichment set at 90kpa and its suppose to force the ecu into Open loop anytime it sees boost. Any ideas of what I can adjust? I'm convinced its either staying in closed loop to long or something in the closed loop options is effecting it in open loop. STFT's are disabled in open loop.

Attached is my tune. It is currently Open Loop only with STFT's disabled. I've disabled the closed loop by changing the closed loop enable settings to 281 degrees to enable closed loop.As found 5-2-20.hpt

[Evo8john]

I can't open the file where I am currently, but have you made sure to disable the LTFT? I know that can cause corrections to occur at WOT as well in some instances.

[Jwoodman]

Yes I've disabled the LTFT's as well. I set the min ect to 281 in order for them to start doing anything.

[Jwoodman]

Just went back through my logs. At 6 psi of boost and 61% throttle it shows that it is still in closed loop operation and the STFT's are pulling fuel out. Is there another way to disable closed loop above 90kpa other then through boost enrichment? For some reason its not going into open loop above 90kpa like it suppose to.

[5FDP]

You should read the tune better and you'd see some other things that stand out.



The 5,500rpm delay for PE is still there, you also left the 60 second time delay for PE there. You also left the enable torque value at 100%, that should be cut in half if you touch anything TM related.

Power enrichment should not be set to 1.000, you still want PE to work before you get into BE.

So do these settings and try again.

PE KPA enable of 85kpa.
Enable torque 50%.
Set the RPM delay to something way low like 1,000rpm.
Zero out the 60 second time delay.
Set the BE enable to 110 kpa.

The PE EQ ratio set that to 1.200.

Then have the BE 100kpa cell start at 1.200, the 105 kpa cell can be 1.22 and then 110kpa can stay like you have it at 1.25.


Your open loop EQ ratio table should not have .93 where it runs at for operating temp. That is going to screw everything up when you enter closed loop. If you tune it rich for .93 in open loop but the closed loop wants 1.00, you just shafted yourself by calibrating it wrong.

[JonathanLeskewich]

Hey I know this is an old thread but I have the same problem! Additional question…

In PE Mode should closed loop still show as active “Yes” in the scanner and only fuel trim learn is “NO”?

[doorev800]

Hey I know this is an old thread but I have the same problem! Additional question…

In PE Mode show closed loop still show as active “Yes” in the scanner and only fuel trim learn is “NO”?

I was out today tuning a truck running the 2 bar op system...

closed loop will go to yes when it hits the preset engine temp under "Closed Loop Enable" and will stay that way until the temp drops below the preset.

As for fuel trim learn- that changes with PE engagement.. thats how its been on a truck I am tuning-2003 5.3 with whipple and using the 2 bar op system.