Odd high idle issue

[5.3LS10]

I have an MS3X running fully sequential on a LQ4 LS 6.0L. I have about 60-70 miles on the combo and for the most part have VE, spark, and AE tuned so that it drives smooth. One issue I am having now is that every now and then when I get to a stop sign the idle hangs around 1500 rpm. I can tap the throttle a few times and it does not appear to be hanging up. I also had this issue with it idling in the garage and I was able to verify that the throttle body was closed all the way. I have also noticed that the WUE LED on the Megasquirt and the indicator in Tunerstudio show that it is activated up into the 190* range and this is usually when I am noticing the problem. Unfortunately the log that I had from tonight does not show that. Can someone please look over my settings and see if I missed something between Closed Loop idle control and WUE.

Thanks
Shane

[Matt Cramer]

Looks like closed loop idle is not engaging at the points where the idle hangs. Try raising RPMdot threshold to 100.

[5.3LS10]

Looks like closed loop idle is not engaging at the points where the idle hangs. Try raising RPMdot threshold to 100.

Sorry I have not had a chance to check this change yet. Its been either 90* or 40 and raining here... and the engine has started to develop a little knock so we are looking at trying to diagnose that now. I will try it tomorrow maybe. Can you explain to me where in the logs you saw that and made that clarification? Just would like to learn some more about troubleshooting issues with megalog viewer

[Matt Cramer]

I checked the status indicators and saw the bit for closed loop idle had not turned on. See the TunerStudio reference manual for how to use the status bits.

[5.3LS10]

I checked the status indicators and saw the bit for closed loop idle had not turned on. See the TunerStudio reference manual for how to use the status bits.

Sorry it's been a long couple weeks. So the engine spun a cam bearing so we swapped out another I had on the stand 5.3 vs 6.0. I did notices the status bit not sngaging which is why I do not understand why it's not engaging. All of the criteria should have veen.met. also i changed the tpsdot hreshold to 100 and it is still idling around 1500.

[5.3LS10]

so while running i tried commanding the IAC down very low and could not get the car to go down below 1000-1100 rpm. But every now and then it will go 850-900. Would it be that maybe there is some carbon buildup in the IAC that is not allowing the plunger to seat all the way? I am going to pull the valve anyways and make sure its clean.

[Matt Cramer]

Please post a data log of what happened and the current MSQ.

[5.3LS10]

Please post a data log of what happened and the current MSQ.

Here they are. There are two files because the laptop screen accidentally closed and killed the datalog

[ashford]

ive had a similar problem, it appears the iac gets blown open by the turbo, a new iac mostly took care of the problem.