Need help w idle - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

joshnmn · 10-07-2022, 03:57 PM

My 18 yo just got a 2010 2SS that he loves. Of course dad can't leave anything alone

.

I was looking through the tune and it looked like a stock tune... Mostly. Someone had gone in and essentially defeated traction control (enable RPM 8k+). So anyway, I returned that to stock and then disabled DoD. That's it, then wrote it to the ECU .

First time I started it I couldn't get it to idle. Had to put about 20% throttle to keep it running. I fought with it all day yesterday, doing tb relearn, disconnecting battery, everything. Still no luck.

I left the battery unhooked overnight, reconnected it and it started right up and idled perfectly... For about 30 seconds, then started losing its mind again.

Any thoughts? Anyone know what happens around 30 seconds in the startup script?

dreksnot · 10-07-2022, 04:09 PM

I hope "someone" had mind enough to save the starting tune (one on the car before implementing changes) before flashing. Just reflash the original and go from there. If "someone" didn't.....

joshnmn · 10-07-2022, 05:59 PM

Already done. Same results

dreksnot · 10-07-2022, 06:16 PM

What has been done to the car (mods)?

Idle Startup Airflow only tapers for 4 seconds. Engine coolant and inlet air temperature affect idle; changes spark, airflow, fueling and tables that modify those parameters.

Generally speaking, airflow is the highest culprit in idle tuning, and heavily relates to my first question above.

joshnmn · 10-07-2022, 10:15 PM

It has a CAI and no mufflers, which I guess might* improve airflow, but it had the stock tune in it before and ran fine

joshnmn · 10-08-2022, 07:16 PM

I let it sit overnight and tried this afternoon. Same results

I think that would tend to eliminate any temperature effect.

morepowerjoe · 10-09-2022, 01:22 AM

Idk buddy. You goofed something up. Maybe you thought you saved the original tune but didn't because it has no reason not to run the same if you loaded the previous tune correctly. I would do a data log and watch the throttle % and see if the throttle is actually closing on you. Also see if it's in closed loop or open loop when you first start it, I believe it should be in open loop, check your fuel pressure, and make sure your AFR is commanding at 14.6. That is the extent of my knowledge of tuning. Sorry just trying to help.

morepowerjoe · 10-09-2022, 01:25 AM

One other thing I was thinking about is maybe whatever the ecu had learned was apparently lost and maybe it just has to relearn whatever was lost?

joshnmn · 10-09-2022, 01:50 AM

That's exactly what it needs to do. I just don't know how to get there from here.

dreksnot · 10-09-2022, 11:58 AM

Quote:

Originally Posted by morepowerjoe

Idk buddy. You goofed something up. Maybe you thought you saved the original tune but didn't because it has no reason not to run the same if you loaded the previous tune correctly. I would do a data log and watch the throttle % and see if the throttle is actually closing on you. Also see if it's in closed loop or open loop when you first start it, I believe it should be in open loop, check your fuel pressure, and make sure your AFR is commanding at 14.6. That is the extent of my knowledge of tuning. Sorry just trying to help.

Sounds about right. When approximately 20sec after startup and shifting over from OL to CL, your O2 sensors have heated up and start to command AFR. Log "Fuel System #1 Statue (SAE) and you can see if this transition is the point at which your idle goes south. If so, then your airflow or fueling is highly suspect. Possible that an O2 sensor is faulty too. That being said, have you compared your current tune with a stock tune downloaded from the HP Repository (make sure it's a real stock tune and not one that someone uploaded claiming it's stock (download multiples))? As for an ECU "relearning," that usually means it's using/calculating LTFT (long term fuel trims) for idle/cruise - determining a "saved" amount of extra or less fuel to add/subtract to keep the engine running at Stoich during idle/cruise. You can clear those (temporary) numbers going into the Diagnostic and Info in the Scanner. However, generally the STFT (short term) would compensate until the LTFT catch up while running over time. Still, lots of things that could be considered. Wouldn't hurt to load up your tune and a log here to show what's happening.

joshnmn · 10-09-2022, 01:20 PM

Thank you for the input. That is exactly what I have been looking for and felt was the culprit.

Yes, I have compared the tune to several stock tunes (and also the not stock tunes). That's how I found out that the traction control enable/disable is the only cell that was different.

I'll definitely log the fuel status PID and force it to open loop. That's the answer- Something to show when it shifts to closed loop. Thanks!

FasNuf · 10-09-2022, 01:35 PM

What tuning software are you using to flash?

joshnmn · 10-09-2022, 06:57 PM

HPTuners

Ok, getting somewhere now. First attempt today it started right up and idled great, right up until it went into closed loop. I had PID "closed loop active" on my channel list and it went to Yes and the car started spitting and sputtering so I shut it down. Didn't save that log because I thought we nailed it.

So the I failed it to open loop (O2 readiness temp to 400) and tried it again. No change, won't idle and I have to give it ~25% throttle to keep it running. Fudge

Last attempt was weird, and I did save that log. I'll upload it tomorrow. While I was holding it steady, the RPM (and O2/spark) would hunt every second or so. RPM would change from 1800-1200 and back with no throttle change. Again, all open loop.

Next things to do are swap MAP, then MAF sensors.

FasNuf · 10-09-2022, 07:15 PM

Did you try WRITE ENTIRE?

10-07-2022, 04:09 PM	#2
dreksnot Served USN - Atomic Chimp Drives: 2021 Camaro ZL1 1LE A10 (stock) Join Date: Jul 2012 Location: Fort Collins, CO Posts: 1,709 View My Garage	I hope "someone" had mind enough to save the starting tune (one on the car before implementing changes) before flashing. Just reflash the original and go from there. If "someone" didn't..... __________________ > > 2021 Camaro ZL1 1LE A10 > > Past Builds: 2013 Twin-Turbo LSX434 M6 - 1,359rwhp daily

10-07-2022, 06:16 PM	#4
dreksnot Served USN - Atomic Chimp Drives: 2021 Camaro ZL1 1LE A10 (stock) Join Date: Jul 2012 Location: Fort Collins, CO Posts: 1,709 View My Garage	What has been done to the car (mods)? Idle Startup Airflow only tapers for 4 seconds. Engine coolant and inlet air temperature affect idle; changes spark, airflow, fueling and tables that modify those parameters. Generally speaking, airflow is the highest culprit in idle tuning, and heavily relates to my first question above. __________________ > > 2021 Camaro ZL1 1LE A10 > > Past Builds: 2013 Twin-Turbo LSX434 M6 - 1,359rwhp daily

10-09-2022, 01:22 AM	#7
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,232	Idk buddy. You goofed something up. Maybe you thought you saved the original tune but didn't because it has no reason not to run the same if you loaded the previous tune correctly. I would do a data log and watch the throttle % and see if the throttle is actually closing on you. Also see if it's in closed loop or open loop when you first start it, I believe it should be in open loop, check your fuel pressure, and make sure your AFR is commanding at 14.6. That is the extent of my knowledge of tuning. Sorry just trying to help. __________________ DSS Pistons, Eagle ESP L19 Rods, ARP Head and Main Studs, TSP PRC CNC Ported Heads milled .030, Cometic .040 Head Gaskets, GPI SS3 VVT Camshaft, GM Racing Lifters, CHE Trunnions, Melling 10355HV Oil Pump, Cold Air Inductions CAI, Fast LSXR Intake Manifold, Nick Williams 103 TB, TSP Longtubes, ZL1 Fuel Pump, Mishimoto Radiator and Oil Cooler, 3600 Circle D Converter, Tru Cool 40k Tranny Cooler, Fluid Dynamics Balancer, EBC 3GD Rotors with EBC Bluestuff NDX Pads, Bilstein B6 Shocks / Struts with Eibach ZL1 Drop Springs Build Thread https://www.camaro5.com/forums/showthread.php?t=609817

10-09-2022, 01:25 AM	#8
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,232	One other thing I was thinking about is maybe whatever the ecu had learned was apparently lost and maybe it just has to relearn whatever was lost? __________________ DSS Pistons, Eagle ESP L19 Rods, ARP Head and Main Studs, TSP PRC CNC Ported Heads milled .030, Cometic .040 Head Gaskets, GPI SS3 VVT Camshaft, GM Racing Lifters, CHE Trunnions, Melling 10355HV Oil Pump, Cold Air Inductions CAI, Fast LSXR Intake Manifold, Nick Williams 103 TB, TSP Longtubes, ZL1 Fuel Pump, Mishimoto Radiator and Oil Cooler, 3600 Circle D Converter, Tru Cool 40k Tranny Cooler, Fluid Dynamics Balancer, EBC 3GD Rotors with EBC Bluestuff NDX Pads, Bilstein B6 Shocks / Struts with Eibach ZL1 Drop Springs Build Thread https://www.camaro5.com/forums/showthread.php?t=609817

10-09-2022, 01:35 PM	#12
FasNuf Drives: 2014 Camaro ZL1 Join Date: Jul 2019 Location: Oregon Posts: 1,703 View My Garage	What tuning software are you using to flash? __________________ . . . . https://www.youtube.com/channel/UCgN...etl17hA/videos

10-07-2022, 03:57 PM	#1
joshnmn 2&THEHIT Drives: 5th Gen Camaro; 5th Gen Ram 3500 Join Date: Mar 2018 Location: Garner, NC Posts: 1,103 View My Garage	Need help w idle My 18 yo just got a 2010 2SS that he loves. Of course dad can't leave anything alone . I was looking through the tune and it looked like a stock tune... Mostly. Someone had gone in and essentially defeated traction control (enable RPM 8k+). So anyway, I returned that to stock and then disabled DoD. That's it, then wrote it to the ECU . First time I started it I couldn't get it to idle. Had to put about 20% throttle to keep it running. I fought with it all day yesterday, doing tb relearn, disconnecting battery, everything. Still no luck. I left the battery unhooked overnight, reconnected it and it started right up and idled perfectly... For about 30 seconds, then started losing its mind again. Any thoughts? Anyone know what happens around 30 seconds in the startup script?

10-07-2022, 05:59 PM	#3
joshnmn 2&THEHIT Drives: 5th Gen Camaro; 5th Gen Ram 3500 Join Date: Mar 2018 Location: Garner, NC Posts: 1,103 View My Garage	Already done. Same results

10-07-2022, 10:15 PM	#5
joshnmn 2&THEHIT Drives: 5th Gen Camaro; 5th Gen Ram 3500 Join Date: Mar 2018 Location: Garner, NC Posts: 1,103 View My Garage	It has a CAI and no mufflers, which I guess might* improve airflow, but it had the stock tune in it before and ran fine

10-08-2022, 07:16 PM	#6
joshnmn 2&THEHIT Drives: 5th Gen Camaro; 5th Gen Ram 3500 Join Date: Mar 2018 Location: Garner, NC Posts: 1,103 View My Garage	I let it sit overnight and tried this afternoon. Same results I think that would tend to eliminate any temperature effect.

10-09-2022, 01:50 AM	#9
joshnmn 2&THEHIT Drives: 5th Gen Camaro; 5th Gen Ram 3500 Join Date: Mar 2018 Location: Garner, NC Posts: 1,103 View My Garage	That's exactly what it needs to do. I just don't know how to get there from here.

10-09-2022, 01:20 PM	#11
joshnmn 2&THEHIT Drives: 5th Gen Camaro; 5th Gen Ram 3500 Join Date: Mar 2018 Location: Garner, NC Posts: 1,103 View My Garage	Thank you for the input. That is exactly what I have been looking for and felt was the culprit. Yes, I have compared the tune to several stock tunes (and also the not stock tunes). That's how I found out that the traction control enable/disable is the only cell that was different. I'll definitely log the fuel status PID and force it to open loop. That's the answer- Something to show when it shifts to closed loop. Thanks!

10-09-2022, 06:57 PM	#13
joshnmn 2&THEHIT Drives: 5th Gen Camaro; 5th Gen Ram 3500 Join Date: Mar 2018 Location: Garner, NC Posts: 1,103 View My Garage	HPTuners Ok, getting somewhere now. First attempt today it started right up and idled great, right up until it went into closed loop. I had PID "closed loop active" on my channel list and it went to Yes and the car started spitting and sputtering so I shut it down. Didn't save that log because I thought we nailed it. So the I failed it to open loop (O2 readiness temp to 400) and tried it again. No change, won't idle and I have to give it ~25% throttle to keep it running. Fudge Last attempt was weird, and I did save that log. I'll upload it tomorrow. While I was holding it steady, the RPM (and O2/spark) would hunt every second or so. RPM would change from 1800-1200 and back with no throttle change. Again, all open loop. Next things to do are swap MAP, then MAF sensors.

10-09-2022, 07:15 PM	#14
FasNuf Drives: 2014 Camaro ZL1 Join Date: Jul 2019 Location: Oregon Posts: 1,703 View My Garage	Did you try WRITE ENTIRE? __________________ . . . . https://www.youtube.com/channel/UCgN...etl17hA/videos