LQ4 turbo tuning questions

[vipergtrdj]

Having small problems trying to tune the following - LQ4, 42lb injectors @ 58psi, gt45 turbo, wastegate set to 12psi, 2 bar MAP sensor. I plan on putting 80lb injectors at some point. Still learning how to tune everything.

Got it to start and idle, but when I drop it into any gear it dies right out. wideband gauge shows its always running rich (11), but voltage for EGR shows otherwise. So I believe the wideband gauge is malfunctioning. I have the wideband wired into EGR so I can log that via HPtuners. According to HPtuners its not rich at idle.

I have tried logging and changing the VE table and adjusting the cell when its in gear, but it does nothing. I know the VE table is a mess, was just trying to get it to idle in Park and Drive, I don't think I was giving the correct data for the injectors (bought them 2nd hand). I adjusted the injector pulse until I got it to idle.

I attached a quick log and the tune, any tips on where to go from here?

Thanks

[vipergtrdj]

did another log, adjusted injectors back to factory settings (still 42lb injectors), and adjusted VE table. I highlighted the VE table and multiplied by .70, seems to idle good. Still dies as soon as put it into gear.

attached log and tune.
idle2.hpl2bar_SD_42lb_new2.hpt

[TCSS07]

your in gear and p/n base running airflow are the same - this is incorrect as your in gear airflow will always need to be higher due to the extra load - add 2 g/s to your base running airflow for in gear to start and see how it responds and work from there
here is the link for the idle tuning guide - https://forum.hptuners.com/showthrea...e-(w-pictures)

[5FDP]

What 2 bar sensor are you using?

When the engine dies the map KPA spikes to 105kpa, that is wrong. The linear and offset settings must match the sensor you are running. You also need to remove the 1 bar MAP channel and replace it with the 2 bar MAP channel so you can read kpa over 105. Right now we really don't know how high the MAP is reading because it's maxed at 105kpa.

[vipergtrdj]

your in gear and p/n base running airflow are the same - this is incorrect as your in gear airflow will always need to be higher due to the extra load - add 2 g/s to your base running airflow for in gear to start and see how it responds and work from there
here is the link for the idle tuning guide - https://forum.hptuners.com/showthrea...e-(w-pictures)

Thank you. I found that same link after some searching and was able to get it to idle and shift into gear without dying. I did find the airflow was all messed up. I checked it against a stock 6.0 tune, not sure how it got changed but I reverted back to stock settings and that appeared to do the trick.

What 2 bar sensor are you using?

When the engine dies the map KPA spikes to 105kpa, that is wrong. The linear and offset settings must match the sensor you are running. You also need to remove the 1 bar MAP channel and replace it with the 2 bar MAP channel so you can read kpa over 105. Right now we really don't know how high the MAP is reading because it's maxed at 105kpa.

The part number is 12615136. I was told its a OEM Camaro 2 bar sensor. What should the KPA be when the engine dies, or when its off? I also removed the 1bar MAP channel and replaced it with the 2 bar MAP. I will do a new log tomorrow.

Once I got the airflow adjusted I was able to move the truck some, but soon as I gave it gas it stalled out. Wideband didn't seem to register it quick enough but appears it was lean. Highest it showed was 17.7 after some throttle was applied. Also showed the MAP at 105KPA. I have attached a log showing it at
IDLE4.hpl

edit - found the 2bar map scaling on sloppy mechanics wiki page, I have adjusted the tune for it and will try it out tomorrow. Could the bad scaling be the reason it would die as soon as I would give it gas to move ? Idles fine in gear and park now. Slowly making progress and learning

[5FDP]

The KPA with the key on engine off should be roughly 100kpa at sea level, less if you live in the mountains.

The linear and offset values should be 200/10.33 for that sensor.

I didn't view the tune on this computer to check what values you have in there right now.

[vipergtrdj]

The KPA with the key on engine off should be roughly 100kpa at sea level, less if you live in the mountains.

The linear and offset values should be 200/10.33 for that sensor.

I didn't view the tune on this computer to check what values you have in there right now.

The tune did have it set for 200/10.33. Sloppy mechanics wiki says 207.66/9.00 for 2 bar MAP.
https://sites.google.com/site/sloppy...identification

[5FDP]

What sloppy says can still be wrong. And that page doesn't give you a part number, it just says 2 bar GM MAP and there are several 2 bar sensor on the market.

And clearly it is if you key on engine off KPA is at 105kpa or higher. It needs to match your area, so try to change the numbers around so it reads correctly.

[vipergtrdj]

sounds good. I will adjust some and see what it reads with ignition on, engine off. I found a thread that gave a couple different linear and offset numbers to try with that part number. I will make some changes and see how it logs tomorrow.

[5FDP]

Another thing or two here.

Set the MAF dtc's to MIL on first error, should be that way for speed density. Raise the dynamic airflow high rpm disable to 8,000rpm.

How come you say you have the injectors that are 42lb/hr at 58psi but you are putting in data that says they over 51-56lb/hr??

I mean if they are 42lb/hr at 43.5psi, then I could it being in the 50's at 58psi.

I would suggest changing up the power enrichment and boost enrichment settings too, so it's safer. Like right now you'd have to reach over 90kpa and be well over 70-80% throttle to enter BE.

Try to make it so that your rpm delays and map kpa settings are the end triggers, if that makes sense.

Like have the cold/hot pedal be a more reasonable 50-60% throttle, have the PE mpa enable at 80-90kpa, boost enrichment kpa should be 110kpa. Set the Power enrichment EQ ratio to a mild air fuel ratio of like 12.0 afr. Then slope the fuel into the boost enrichment as the KPA rises. Start the BE at 12.0 at 100kpa, then slope the fuel to your last value of 1.26 at 5-7psi. Lower the rpm delay to 1,500-1,700rpm. Zero out the ECT adder at coolant temps above 130-140, you don't need that adding to the commanded air fuel ratio in PE/BE.

Open loop EQ ratio should not be 1.00 for the entire table either. Take your stock table and paste it back in there and have to level out to 1.00 (aka stoich) at temps over 130 degrees. You still want it to command a richer air fuel ratio when it's cold and not stoich right away.

[vipergtrdj]

Another thing or two here.

Set the MAF dtc's to MIL on first error, should be that way for speed density. Raise the dynamic airflow high rpm disable to 8,000rpm.

How come you say you have the injectors that are 42lb/hr at 58psi but you are putting in data that says they over 51-56lb/hr??

I mean if they are 42lb/hr at 43.5psi, then I could it being in the 50's at 58psi.

I would suggest changing up the power enrichment and boost enrichment settings too, so it's safer. Like right now you'd have to reach over 90kpa and be well over 70-80% throttle to enter BE.

Try to make it so that your rpm delays and map kpa settings are the end triggers, if that makes sense.

Like have the cold/hot pedal be a more reasonable 50-60% throttle, have the PE mpa enable at 80-90kpa, boost enrichment kpa should be 110kpa. Set the Power enrichment EQ ratio to a mild air fuel ratio of like 12.0 afr. Then slope the fuel into the boost enrichment as the KPA rises. Start the BE at 12.0 at 100kpa, then slope the fuel to your last value of 1.26 at 5-7psi. Lower the rpm delay to 1,500-1,700rpm. Zero out the ECT adder at coolant temps above 130-140, you don't need that adding to the commanded air fuel ratio in PE/BE.

Open loop EQ ratio should not be 1.00 for the entire table either. Take your stock table and paste it back in there and have to level out to 1.00 (aka stoich) at temps over 130 degrees. You still want it to command a richer air fuel ratio when it's cold and not stoich right away.

I set the MAF dtc's and raise the rpm disable to 8,000rpms. I plan on keeping it in SD.
The injectors was a typo - they are 42lb at 43.5psi. I have them running at the stock pressure of 58psi, sorry about that.

I made some of the changes you advised, I also have a friend that has a similar setup, 5.3 with 42lb injectors (@58psi), 76mm ebay turbo, 2bar map. He sent me his tune and I adjusted some values based off that, I will work on the timing end of things once its running and moving. He says PE set for 11.5 afr, and knock adjusted for safety.

How does it look ?

[5FDP]

BE needs to start at 1.175 at 100kpa because it's the end of your PE table, then interpolate from the last value. Can't have it start over at stoich at 100kpa because it would be lean entering boost.

[vipergtrdj]

BE needs to start at 1.175 at 100kpa because it's the end of your PE table, then interpolate from the last value. Can't have it start over at stoich at 100kpa because it would be lean entering boost.

Made the changes. Everything else look fine for a base besides that?

[5FDP]

Don't forget about what the guy in post 3 said about your idle airflow.

[vipergtrdj]

Don't forget about what the guy in post 3 said about your idle airflow.

got it. I must have changed it in the other tune and not this one. I adjusted it and added 2g/s as recommended. I will put the tune on the truck and log it tomorrow, see how the results are.

[vipergtrdj]

I messed with it some today during this snow storm. I adjusted the MAP sensor settings some, with no good results. It kept reading 105kpa ignition on, engine off. So I decided to revert to stock, threw on a stock tune with adjustments done to fueling for the 42lb injectors, and put OEM 1 bar map sensor in. Key on ignition off it read 99kpa, so I cranked it over and started right up. Threw it in gear and moved fine. Figured I would adjust the VE some down the road. At idle the OEM map sensor read 34kpa, vs the 2bar map that was reading around 50kpa if I recall correctly. Truck idles smooth around 700-750rpms, any lower and hiccups occasionally.

So I am leaning towards a bad 2bar map sensor ? I honestly can't remember where I got this MAP sensor, got it last summer when I was gathering parts for the turbo build.

[vipergtrdj]

I picked up a new ACDelco 2bar map sensor. Adjust the map scaling for it and now reads 100kpa key on engine off.
It idles for about 10 to 20 seconds then shuts off. Idling its roughly 30-35kpa.
Now if I plug in the 1bar map and put the 1 bar tune it runs and drives great. I copied the VE table over to the 2bar map but at idle it stalls out.
Where should I look ?

[5FDP]

Post the tune with the new 2 bar map and a log with that file.

[vipergtrdj]

Sorry for the delay in responding. Attached are the tune files - the 2 bar tune , and stock 1 bar tune. I will get a log when I get back home, hopefully tomorrow.
I made sure the MAF DTCs were set to MIL first error, SES off, and high rpm disable 8000rpms.

Does anything in the tune look out of place for the 2 bar tune or why it would stall out after roughly 10seconds ?

[vipergtrdj]

Did some logging. It started fine on its own today. I logged idle (VE was running lean originally), then adjusted VE so it idle'd smoother, then when give it throttle it leans out, so more work to VE needed I believe.

The new 2 bar MAP seems to be reading correctly, with key on engine off it bounces between 0 and 100, think may be vcm scanner.