Weird high idle - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Valkyrie14 · 06-07-2022, 06:32 PM

She is idling around 1800 when I am in neutral coasting to a stop. When I come to a complete stop the idle drops to 800. If I am driving and coasting in neutral and I put it into gear, the idle drops when I engage the clutch.

Changes to things, installed new twin disc clutch 350 miles ago, no issues, a little chattery. I have a tick master cylinder and I have been trying different lengths for the range of the pedal. Everything else is as it has been.

morepowerjoe · 06-08-2022, 03:07 AM

Were you tuned recently?

gtstorey · 06-08-2022, 06:33 AM

Vacuum leak?

Valkyrie14 · 06-08-2022, 12:20 PM

Quote:

Originally Posted by morepowerjoe

Were you tuned recently?

My last tune was March 2021, when I put in my dual fuel pump.

Valkyrie14 · 06-08-2022, 12:23 PM

Quote:

Originally Posted by gtstorey

Vacuum leak?

Seems like vacuum leak is the likely issue. All of my hoses look good, but I will run a spray test.

I just cleaned my CAI, it was dirty. I was thinking more air is coming, but not a massive amount of more air than before.

morepowerjoe · 06-08-2022, 12:30 PM

Yeah I think it could likely a vacuum leak as well.

Valkyrie14 · 06-08-2022, 10:06 PM

So, I did a quick check of the vacuum lines. No obvious leak, but I have a capped stem on the blower’s snout and it was dried and leaking so I replaced it. Did not affect any change in the idle, but when I got in to drive the power steering was out, ABS light and the emergency brake light was on as well. I did a scan of the system and 15 codes came up. I cleared them and then unplugged the battery for a reset. All of the lights went off and the codes didn’t come back. Crazy.

Today I isolated more of the issue. I am going 35 in third gear at 2000 rpms, my AFR was reading 14-15. Then when I shift into neutral the rpms stay pegged at 2000 rpms and the AFR ticks up to 15-15.5.

Also, when coasting and the rpms are at 2000 I can push in the clutch and the rpms drop to 800. That doesn’t make sense to me, the clutch pedal and slave cylinder are not connected to the throttle body or MAF at all. Unless there is a sensor or something I don’t know about.

This is starting to drive me crazy.

morepowerjoe · 06-09-2022, 07:45 AM

Did you remove the maf sensor when you cleaned the cai or did you maybe over oil the filter?

gtstorey · 06-09-2022, 07:51 AM

Usually that many codes would indicate an electrical issue, either a weak battery or bad ground.

If not, and this appeared immediately after cleaning the CAI I would suspect something going on with the MAF. Is the filter an oiled filter? Maybe it pulled oil onto the MAF. If not maybe wiring on the MAF.

Are you logging in HP Tuners? If so you need to look at the values for the various sensors and controllers and see if something isn't reacting correctly.

As far as the clutch not being tied to the throttle body, everything is tied together with load tables and I think even the clutch position switch.

Valkyrie14 · 06-09-2022, 08:22 AM

Quote:

Originally Posted by gtstorey

Usually that many codes would indicate an electrical issue, either a weak battery or bad ground.

If not, and this appeared immediately after cleaning the CAI I would suspect something going on with the MAF. Is the filter an oiled filter? Maybe it pulled oil onto the MAF. If not maybe wiring on the MAF.

Are you logging in HP Tuners? If so you need to look at the values for the various sensors and controllers and see if something isn't reacting correctly.

As far as the clutch not being tied to the throttle body, everything is tied together with load tables and I think even the clutch position switch.

It is an oiled filter, that is a good point and easy enough to check the MAF. I use HP, but I have it for others to tune. I am generally aware of what HP scans are telling me, but I don’t know what readings would be normal for most sensors.

NOT A 45 · 06-09-2022, 08:25 AM

Quote:

Originally Posted by gtstorey

Usually that many codes would indicate an electrical issue, either a weak battery or bad ground.

If not, and this appeared immediately after cleaning the CAI I would suspect something going on with the MAF. Is the filter an oiled filter? Maybe it pulled oil onto the MAF. If not maybe wiring on the MAF.

Are you logging in HP Tuners? If so you need to look at the values for the various sensors and controllers and see if something isn't reacting correctly.

As far as the clutch not being tied to the throttle body, everything is tied together with load tables and I think even the clutch position switch.

Yes the clutch pedal position switch operates off a 5v reference from the ecm. If he has a scan tool, it should be 4v with clutch released and 1v with pedal to the floor. I've never seen the switch cause a drivability concern but that doesn't mean that it cant

NOT A 45 · 06-09-2022, 08:33 AM

Quote:

Originally Posted by Valkyrie14

It is an oiled filter, that is a good point and easy enough to check the MAF. I use HP, but I have it for others to tune. I am generally aware of what HP scans are telling me, but I don’t know what readings would be normal for most sensors.

I've never seen a MAF cause a high idle condition, only a rich or lean condition. Also you said it idles normally when at a complete stop. I suspect a problem within the ecm.

gtstorey · 06-09-2022, 09:05 AM

Quote:

Originally Posted by Valkyrie14

It is an oiled filter, that is a good point and easy enough to check the MAF. I use HP, but I have it for others to tune. I am generally aware of what HP scans are telling me, but I don’t know what readings would be normal for most sensors.

Time to start learning a little more about scanning with HP Tuners, not that I'm anymore than a beginner myself. You should be able to watch things Accelerator Pedal Position, throttle position etc voltages and at least conform that they seem to be changing in relation to what your are asking for. Maybe the APP is messing up and the ECM isn't getting the signal that you have let off the gas to shift. You can also post logs on the HP Tuner forums and get people to review them to look for problems.

Have you looked at your tune to see what DTC's have been turned off? Your tuner may have turned something off that might be pointing to your problem.

Risingson05 · 06-09-2022, 09:22 AM

Umm it might be too simple but could it possibly be your throttle position sensor is acting lazy ? Or throttle blade is dirty

06-07-2022, 06:32 PM	#1
Valkyrie14 Valkyrie14 Drives: Chevrolet Camaro SS Join Date: Mar 2020 Location: Eau Claire, Wisconsin Posts: 962	Weird high idle She is idling around 1800 when I am in neutral coasting to a stop. When I come to a complete stop the idle drops to 800. If I am driving and coasting in neutral and I put it into gear, the idle drops when I engage the clutch. Changes to things, installed new twin disc clutch 350 miles ago, no issues, a little chattery. I have a tick master cylinder and I have been trying different lengths for the range of the pedal. Everything else is as it has been. __________________ 2014 SS LS3/LSA Supercharger, 10% Super Damper, 2.55 upper, AGP Dual Pump, ID 1050 injectors, Pegasus solid rear cradle bushings, LT Headers, Roto-Fab CAI, Elite E2 catch can, E85 corn fed, 160 Thermostat, Monster Twin Disk, MGW Short Throw shifter, Tick Clutch Master Cylinder, HP Tuners, JL Audio system.

06-08-2022, 03:07 AM	#2
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,094	Were you tuned recently? __________________ DSS FX Forged Pistons, Eagle ESP L19 Forged Rods, ARP Head and Main Studs, TSP PRC 260 CNC Ported Heads milled .030, Cometic .040 Head Gaskets, GPI SS3 VVT Camshaft, GM Performance Racing Lifters, CHE Trunnions , Molly Pushrods, Melling 10355HV Oil Pump, Cold Air Inductions CAI, Fast LSXR Intake Manifold, Nick Williams 103 TB, TSP 1 7/8" Longtubes with 3" TSP Exhaust, ZL1 Fuel Pump, Mishimoto Radiator, Mishimoto Oil Cooler, Tru Cool 40k Tranny Cooler, 3600 Circle D Converter, Fluid Dynamics Balancer Build Thread https://www.camaro5.com/forums/showthread.php?t=609817

06-08-2022, 12:30 PM	#6
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,094	Yeah I think it could likely a vacuum leak as well. __________________ DSS FX Forged Pistons, Eagle ESP L19 Forged Rods, ARP Head and Main Studs, TSP PRC 260 CNC Ported Heads milled .030, Cometic .040 Head Gaskets, GPI SS3 VVT Camshaft, GM Performance Racing Lifters, CHE Trunnions , Molly Pushrods, Melling 10355HV Oil Pump, Cold Air Inductions CAI, Fast LSXR Intake Manifold, Nick Williams 103 TB, TSP 1 7/8" Longtubes with 3" TSP Exhaust, ZL1 Fuel Pump, Mishimoto Radiator, Mishimoto Oil Cooler, Tru Cool 40k Tranny Cooler, 3600 Circle D Converter, Fluid Dynamics Balancer Build Thread https://www.camaro5.com/forums/showthread.php?t=609817

06-08-2022, 10:06 PM	#7
Valkyrie14 Valkyrie14 Drives: Chevrolet Camaro SS Join Date: Mar 2020 Location: Eau Claire, Wisconsin Posts: 962	So, I did a quick check of the vacuum lines. No obvious leak, but I have a capped stem on the blower’s snout and it was dried and leaking so I replaced it. Did not affect any change in the idle, but when I got in to drive the power steering was out, ABS light and the emergency brake light was on as well. I did a scan of the system and 15 codes came up. I cleared them and then unplugged the battery for a reset. All of the lights went off and the codes didn’t come back. Crazy. Today I isolated more of the issue. I am going 35 in third gear at 2000 rpms, my AFR was reading 14-15. Then when I shift into neutral the rpms stay pegged at 2000 rpms and the AFR ticks up to 15-15.5. Also, when coasting and the rpms are at 2000 I can push in the clutch and the rpms drop to 800. That doesn’t make sense to me, the clutch pedal and slave cylinder are not connected to the throttle body or MAF at all. Unless there is a sensor or something I don’t know about. This is starting to drive me crazy. __________________ 2014 SS LS3/LSA Supercharger, 10% Super Damper, 2.55 upper, AGP Dual Pump, ID 1050 injectors, Pegasus solid rear cradle bushings, LT Headers, Roto-Fab CAI, Elite E2 catch can, E85 corn fed, 160 Thermostat, Monster Twin Disk, MGW Short Throw shifter, Tick Clutch Master Cylinder, HP Tuners, JL Audio system.

06-09-2022, 07:45 AM	#8
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,094	Did you remove the maf sensor when you cleaned the cai or did you maybe over oil the filter? __________________ DSS FX Forged Pistons, Eagle ESP L19 Forged Rods, ARP Head and Main Studs, TSP PRC 260 CNC Ported Heads milled .030, Cometic .040 Head Gaskets, GPI SS3 VVT Camshaft, GM Performance Racing Lifters, CHE Trunnions , Molly Pushrods, Melling 10355HV Oil Pump, Cold Air Inductions CAI, Fast LSXR Intake Manifold, Nick Williams 103 TB, TSP 1 7/8" Longtubes with 3" TSP Exhaust, ZL1 Fuel Pump, Mishimoto Radiator, Mishimoto Oil Cooler, Tru Cool 40k Tranny Cooler, 3600 Circle D Converter, Fluid Dynamics Balancer Build Thread https://www.camaro5.com/forums/showthread.php?t=609817

06-08-2022, 06:33 AM	#3
gtstorey Drives: 2010 Camaro SS2,L99, LSA SC Join Date: Aug 2017 Location: Huntsville, AL Posts: 2,147	Vacuum leak?

06-09-2022, 07:51 AM	#9
gtstorey Drives: 2010 Camaro SS2,L99, LSA SC Join Date: Aug 2017 Location: Huntsville, AL Posts: 2,147	Usually that many codes would indicate an electrical issue, either a weak battery or bad ground. If not, and this appeared immediately after cleaning the CAI I would suspect something going on with the MAF. Is the filter an oiled filter? Maybe it pulled oil onto the MAF. If not maybe wiring on the MAF. Are you logging in HP Tuners? If so you need to look at the values for the various sensors and controllers and see if something isn't reacting correctly. As far as the clutch not being tied to the throttle body, everything is tied together with load tables and I think even the clutch position switch.

06-09-2022, 09:22 AM	#14
Risingson05 Drives: 2015 zl1 m6 Join Date: Jan 2020 Location: Alaska Posts: 702	Umm it might be too simple but could it possibly be your throttle position sensor is acting lazy ? Or throttle blade is dirty