High Idle Problem - Solved - Sorta??

MartinLe · 07-14-2023, 03:00 PM

Hey guys,

My car is idling ~200 rpms high with no apparent reason. It is commanded to idle at 775. I have had it smoke tested and no vacuum leak was found. I cleaned the MAF sensor. My tuner did the tb relearn procedure. Nothing has worked so far.

What do you guys think? Thanks in advance for your help.

Gunkk · 07-14-2023, 03:25 PM

And 200 high on a rough idle cam is bad because why again?

What did your tuner say?

ZL14ever · 07-14-2023, 04:13 PM

AC turned on? My car would always add 100rpm to idle when I turn on the AC, regardless of what is commanded

Joshinator99 · 07-14-2023, 04:28 PM

Quote:

Originally Posted by MartinLe

Hey guys,

My car is idling ~200 rpms high with no apparent reason. It is commanded to idle at 775. I have had it smoke tested and no vacuum leak was found. I cleaned the MAF sensor. My tuner did the tb relearn procedure. Nothing has worked so far.

What do you guys think? Thanks in advance for your help.

How does your timing at idle look?

Joshinator99 · 07-14-2023, 04:29 PM

Quote:

Originally Posted by Gunkk

And 200 high on a rough idle cam is bad because why again?

What did your tuner say?

He’s at 775 which is already high enough to compensate for the cam. He’s another 200 over that, so anytime you’re not hitting commanded, something is up. Usually torque model, vacuum leak, etc.

MartinLe · 07-14-2023, 05:37 PM

Quote:

Originally Posted by Joshinator99

How does your timing at idle look?

My tuner just texted me: "timing is 5* at idle and them jumps to 28*. As the timing increases so does the idle, but the map drops also." He found that one of the check valves in the cc is bleeding air by it. He is the one that installed the cc when he did the cam/blower swap. He is checking the routing of the cc. Maybe there's a problem there? He noted that one of the lines tee into the manifold.

MartinLe · 07-14-2023, 05:40 PM

Quote:

Originally Posted by Gunkk

And 200 high on a rough idle cam is bad because why again?

What did your tuner say?

As Josh said, when the car is doing anything other than what the computer is telling it to do, it needs to be sorted out.

ZLRob · 07-15-2023, 06:50 AM

If you are having an issue with your catch can and it has to do with vacuum or check valves that will directly affect the running condition of the car at all times until it is fixed.

Given how modded you are, it is always helpful to have an insight into how HPTuners works and how to make changes outside of what your initial tuner has done so as well when/ if necessary.

MartinLe · 07-20-2023, 02:30 PM

Update on the high idle. I got the car back this morning and she idles at 750 with a nice little lope. My tuner smoke tested her twice; r&r'd the tb to check for anything mechanical that might be the cause; relearned the tb twice; checked the cc for any issues with check valves, etc; nothing. He reached out to Ted. He sent a couple of revisions trying to help. No luck.

So, my guy ended up changing the idle tables. He brought the rolling idle (600) and commanded idle (775) more in line with each other. Commanded idle now is 750. He adjusted the timing and torque tables, at idle, a little.

But the question still remains: why did it start idling fast in the first place? Therefore, this must be called a band-aide since a cause was never found. I don't know about you guys, but I don't like band-aides in this context.

KingLT1 · 07-21-2023, 09:17 AM

Gen 5 ECU's can be finicky like that. If the engine is now hitting commanded idle now, take a melatonin and get some sleep tonight!

MartinLe · 07-22-2023, 12:15 PM

Quote:

Originally Posted by KingLT1

Gen 5 ECU's can be finicky like that. If the engine is now hitting commanded idle now, take a melatonin and get some sleep tonight!

Melatonin it is!

Thanks.

07-14-2023, 03:00 PM	#1
MartinLe Drives: 2017 Chevrolet Camaro ZL1 M6 Join Date: Jul 2020 Location: OR Posts: 479	High Idle Problem - Solved - Sorta?? Hey guys, My car is idling ~200 rpms high with no apparent reason. It is commanded to idle at 775. I have had it smoke tested and no vacuum leak was found. I cleaned the MAF sensor. My tuner did the tb relearn procedure. Nothing has worked so far. What do you guys think? Thanks in advance for your help. __________________ JRE Terminator Rough Idle Cam Magnuson 2650 - 15% lower, 90mm upper FIC+30% DSX Flex fuel/Low side NW 103mm TB/Roto-Fab CAI Monster S Series Elite E2-X 2" TSP LT's BMR:BK063, BK060,TCA061, UTCA060, UTCA063 Weld Beadlocks/17" NT5R2 Last edited by MartinLe; 07-20-2023 at 01:47 PM.

07-15-2023, 06:50 AM	#8
ZLRob Drives: Chevrolet Camaro ZL1 Join Date: May 2022 Location: Concordia Posts: 442	If you are having an issue with your catch can and it has to do with vacuum or check valves that will directly affect the running condition of the car at all times until it is fixed. Given how modded you are, it is always helpful to have an insight into how HPTuners works and how to make changes outside of what your initial tuner has done so as well when/ if necessary. __________________ 2017 Red Hot ZL1 A10 - Apex ARC-8's, 305/ 325 PS4's, DSX 9.06 12% Pulley, NGK HR7 Ruthenium spark plugs, Katech Oil Pump, LME tensioner, DOD delete, Cam, MPI lid, Soler ported 87mm (91mm effective) TB, Granatelli SS plug wires, Cordes LTR reservoir, DMS T-stat housing, Borla X pipe, AFe NPP exhaust, Black Widow Angry Housewife/ Venom 250 mufflers, BMR engine mounts, Banks iDash, Lithium Battery, Course Motorsports phone mount, AEM X- Series, HP Tuners, JMS, E85, 13.6 psi 737 HP/ 779 TQ

07-20-2023, 02:30 PM	#9
MartinLe Drives: 2017 Chevrolet Camaro ZL1 M6 Join Date: Jul 2020 Location: OR Posts: 479	Update on the high idle. I got the car back this morning and she idles at 750 with a nice little lope. My tuner smoke tested her twice; r&r'd the tb to check for anything mechanical that might be the cause; relearned the tb twice; checked the cc for any issues with check valves, etc; nothing. He reached out to Ted. He sent a couple of revisions trying to help. No luck. So, my guy ended up changing the idle tables. He brought the rolling idle (600) and commanded idle (775) more in line with each other. Commanded idle now is 750. He adjusted the timing and torque tables, at idle, a little. But the question still remains: why did it start idling fast in the first place? Therefore, this must be called a band-aide since a cause was never found. I don't know about you guys, but I don't like band-aides in this context. __________________ JRE Terminator Rough Idle Cam Magnuson 2650 - 15% lower, 90mm upper FIC+30% DSX Flex fuel/Low side NW 103mm TB/Roto-Fab CAI Monster S Series Elite E2-X 2" TSP LT's BMR:BK063, BK060,TCA061, UTCA060, UTCA063 Weld Beadlocks/17" NT5R2

07-21-2023, 09:17 AM	#10
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,811	Gen 5 ECU's can be finicky like that. If the engine is now hitting commanded idle now, take a melatonin and get some sleep tonight! __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

07-14-2023, 03:25 PM	#2
Gunkk Thank you Al Oppenheiser! Drives: Red Hot A10 ZL1 Convertible Join Date: Jun 2017 Location: Sarasota, FL Posts: 4,993 View My Garage	And 200 high on a rough idle cam is bad because why again? What did your tuner say?

07-14-2023, 04:13 PM	#3
ZL14ever Drives: 2018 Camaro ZL1 A10 Join Date: Feb 2022 Location: Dubai, UAE Posts: 63	AC turned on? My car would always add 100rpm to idle when I turn on the AC, regardless of what is commanded

User Name		Remember Me?
Password