Turbo 5.3 Microsquirt Idle Issues
Thread Starter
Teching In
Joined: Jul 2022
Posts: 2
Likes: 0
Turbo 5.3 Microsquirt Idle Issues So I'm new to the whole turbo LS world (and definitely in over my head), and after spending some time surfing ideas online and playing around with the tune, I figured I'd drop a line out here to try and get some guidance with this whole deal.
The setup: Bone stock LM7 with Pac 1218's and Siemens Deka 80's, GT45 turbo, GM 3 bar map, Bosch 044, running on Microsquirt, typical low-buck deal.
I cannot for the life of me get this thing to idle leaner. Hangs out around 10.5-11.0 AFR, rich smelling exhaust, smoky, idles poorly, doesn't really like certain throttle inputs, overall just acts strange. I've played around with the VE table, ignition table, injector dead time, required fuel value, and tried just about every idea I can find online without really making much of a difference. Injector pulse width likes to hang around 1.2 to 1.3 ms and idle, which is around the dead time for Deka 80's, and no amount of adjustment seems to change that. Base fuel pressure is set at 43.5 psi. At this point, I'm pretty well out of ideas, and I'm all ears to any suggestions/guidance that's out there. I'll attach the tune file as well as a datalog of the truck running on that tune. Any help is greatly appreciated, Thanks!
The setup: Bone stock LM7 with Pac 1218's and Siemens Deka 80's, GT45 turbo, GM 3 bar map, Bosch 044, running on Microsquirt, typical low-buck deal.
I cannot for the life of me get this thing to idle leaner. Hangs out around 10.5-11.0 AFR, rich smelling exhaust, smoky, idles poorly, doesn't really like certain throttle inputs, overall just acts strange. I've played around with the VE table, ignition table, injector dead time, required fuel value, and tried just about every idea I can find online without really making much of a difference. Injector pulse width likes to hang around 1.2 to 1.3 ms and idle, which is around the dead time for Deka 80's, and no amount of adjustment seems to change that. Base fuel pressure is set at 43.5 psi. At this point, I'm pretty well out of ideas, and I'm all ears to any suggestions/guidance that's out there. I'll attach the tune file as well as a datalog of the truck running on that tune. Any help is greatly appreciated, Thanks!
Are you working with a fully warmed up engine, ase off, wue off, and idle ve(if available) off? All these things, plus the mat correction table can add fuel to the ve number. Are you using a wbo2 sensor? Do you have "incorporate AFR" selected and your ego correction parameters set? EGO correction if active, will show you how far off the ve number is by watching the percentage it's adding or subtracting. You can even set up a gauge on your gauge panel that shows ego correction to do it in real time.
ETA: don't tune with required fuel calcs, or dead time calcs. Enter the correct information and leave it alone.
ETA: don't tune with required fuel calcs, or dead time calcs. Enter the correct information and leave it alone.
Last edited by Scott65; Jul 20, 2022 at 09:54 AM.
Are you sure you don't have an injector issue?
I bought a used set of Deka 80's years ago the previous owner said were like new.
Turns out he ran E85 in them and never pickled them before removal so several of them were gummed up.
As a result I could never get my AFR's above 11.7 because some of the injectors were just dumping fuel.
I bought a used set of Deka 80's years ago the previous owner said were like new.
Turns out he ran E85 in them and never pickled them before removal so several of them were gummed up.
As a result I could never get my AFR's above 11.7 because some of the injectors were just dumping fuel.
Thread Starter
Teching In
Joined: Jul 2022
Posts: 2
Likes: 0
Engine is up to temp, ASE and WUE off. Using an AEM wideband O2, incorporate afr is selected. I'll have to look into the EGO and MAT correction. Didn't see the rest of the replies to this thread until just now, so the only thing I tried tonight was the Barometric sensor setting, which was still selected as the GM 1 bar. Switched it over to 3 bar, and the idle afr did go up to 11.6:1. Not necessarily a major difference, but it certainly won't hurt having the proper sensor selected. I bought the injectors brand new, so I'd like to think they are in good working order, but I have thought about pulling the fuel rail from the intake and testing injectors to make sure nothing strange is happening. More things to try, I'll see what tomorrow brings.
After looking at the MSQ, I'd also try using .9 for the dead time, as the tooltip recommends, and changing to two squirts instead of the 4 you have currently selected. Should require longer opening times with fewer pulses and get you away from the low pulsewidth(non linear) area.
Your going to have to tune that with a laptop and software if they have it for that. There is no wat I was try ot tune a turbo setup with just those options no matter what efi system it was.
