Weird Idle Above 30 mph - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

BossRS4 · 04-09-2017, 10:48 PM

Alright you guys were spot on with my last problem! I hope you can help me out again!

When my car is cold and even when it warms up, it randomly spikes in revs from 500 rpm's to 1,000 rpm's when I am going 30 mph or more in neutral.

Here is a video of it:

Please ignore my loud annoying radar detector, and the poor quality of video.

Sometimes its almost like the car will stall out an drop to 300-400 rpm's. Could it be a bad idle control motor??

What do you guys think?

STUNNAH · 04-10-2017, 12:40 AM

How long are your holding it in neutral and why???Could be active rev matching trying to determine if you're attempting to down shift...Just guessing...

BossRS4 · 04-10-2017, 07:40 AM

Quote:

Originally Posted by STUNNAH

How long are your holding it in neutral and why???Could be active rev matching trying to determine if you're attempting to down shift...Just guessing...

Car is a manual, so when you approach red lights I will sometimes put it into neutral before I come to a stop.

I don't think the 5th gens offered active rev matching in the manuals.

hawk02 · 04-10-2017, 08:54 AM

Sounds like there's a vacuum leak somewhere. You might start by checking the connections on the Roto-Fab intake, especially after the MAF sensor.

runyonwc · 04-10-2017, 10:46 AM

I have a similar type of issue. I didnt really notice it before I installed my headers and had the car tuned. So Im not sure if it is a tune issue or what.

ZMEnow · 04-10-2017, 11:49 AM

Quote:

Originally Posted by hawk02

Sounds like there's a vacuum leak somewhere. You might start by checking the connections on the Roto-Fab intake, especially after the MAF sensor.

Definite vacuum leak... Check as suggested above and also the CAI tube connection to TB and filter element to make sure they are still air tight sealed.

runyonwc · 04-10-2017, 05:07 PM

If it were a vacuum leak, why wouldn't it do it all the time? Why just while the car is rolling? My car does something similar to this while coming to a stop and the car is in neutral. I also have rotofab intake, headers (no cats), and a tune.

crazydave · 04-10-2017, 06:20 PM

Quote:

Originally Posted by BossRS4

Alright you guys were spot on with my last problem! I hope you can help me out again!

When my car is cold and even when it warms up, it randomly spikes in revs from 500 rpm's to 1,000 rpm's when I am going 30 mph or more in neutral.

Here is a video of it:

Please ignore my loud annoying radar detector, and the poor quality of video.

Sometimes its almost like the car will stall out an drop to 300-400 rpm's. Could it be a bad idle control motor??

What do you guys think?

Stock catback? Maybe a vacuum leak somewhere in the NPP system. NPP is open at idle and closed while cruising, this could explain why it only does it while moving.

BossRS4 · 04-11-2017, 09:24 AM

Quote:

Originally Posted by ZMEnow

Definite vacuum leak... Check as suggested above and also the CAI tube connection to TB and filter element to make sure they are still air tight sealed.

I will check this when I get home today from work.

BossRS4 · 04-11-2017, 09:25 AM

Quote:

Originally Posted by crazydave

Stock catback? Maybe a vacuum leak somewhere in the NPP system. NPP is open at idle and closed while cruising, this could explain why it only does it while moving.

Do you think I have a leak somewhere in the exhaust?

BossRS4 · 04-11-2017, 09:26 AM

Quote:

Originally Posted by runyonwc

If it were a vacuum leak, why wouldn't it do it all the time? Why just while the car is rolling? My car does something similar to this while coming to a stop and the car is in neutral. I also have rotofab intake, headers (no cats), and a tune.

That is very odd yours does the same thing.

ABADZL1 · 04-11-2017, 10:11 AM

Look at your vacuum/boost gauge. Is it normal? I doubt it's a vacuum leak. Since you're tuned, I bet spark smoothing has been disabled in your tune. (some tuners do this) I bet this is being caused by a wild swing in the timing tables. More of an issue with big cams. Mine does it every once in a while.

GONMAD510 · 04-11-2017, 10:28 AM

My car does the same thing. It started after I had the parts in my signature installed. I have never got around to asking the tuner about it.

BossRS4 · 04-11-2017, 10:57 AM

Quote:

Originally Posted by ABADZL1

Look at your vacuum/boost gauge. Is it normal? I doubt it's a vacuum leak. Since you're tuned, I bet spark smoothing has been disabled in your tune. (some tuners do this) I bet this is being caused by a wild swing in the timing tables. More of an issue with big cams. Mine does it every once in a while.

I asked Steve from RDP about it and he said to re-load my tune, which I did and it still did not fix it.

04-10-2017, 12:40 AM	#2
STUNNAH "BEASTM*DE" Drives: 2013 ZL1 Black Join Date: Aug 2016 Location: Tennessee Posts: 1,655 View My Garage	How long are your holding it in neutral and why???Could be active rev matching trying to determine if you're attempting to down shift...Just guessing... __________________ Vengeance Racing Stage 1 Kit 575rwhp, 569 rwtq... Rims powder coated gloss black...BFG'S Comp 2 A/S... Dual 10" Kicker Comp S Subs 1200w...

04-10-2017, 08:54 AM	#4
hawk02 Coupe Newbie Drives: '23 CT5-V BW, '21 Corvette HTC Join Date: Jul 2011 Location: Columbus, Ohio Posts: 3,307 View My Garage	Sounds like there's a vacuum leak somewhere. You might start by checking the connections on the Roto-Fab intake, especially after the MAF sensor. __________________

04-11-2017, 10:11 AM	#12
ABADZL1 ZL1 Pilot Drives: 2013 ZL1 Join Date: Apr 2014 Location: TN Posts: 1,670 View My Garage	Look at your vacuum/boost gauge. Is it normal? I doubt it's a vacuum leak. Since you're tuned, I bet spark smoothing has been disabled in your tune. (some tuners do this) I bet this is being caused by a wild swing in the timing tables. More of an issue with big cams. Mine does it every once in a while. __________________ GP Tuning 2.5 Cam, RPS Carbon Twin Clutch, Ported Blower, Kook's Headers, Cold Air Inductions CAI, ID850's, 9.17 Lower, 2.5 Upper, JMS BAP, Pedders Front Radius Arm Inserts, Whiteline Subframe Inserts, Tuned by me with HP Tuners Idle Clip Link...........https://www.youtube.com/watch?v=gTL8S9eHwbs

04-11-2017, 10:28 AM	#13
GONMAD510 Drives: 2013 ZL1 M6 Join Date: Sep 2016 Location: CA Bay Area Posts: 248	My car does the same thing. It started after I had the parts in my signature installed. I have never got around to asking the tuner about it. __________________ Fast 850cc Injectors, ATI Balancer, 8.66 Lower Pulley, 2.55 Upper Pulley, Lingenfelter CAI, Kooks LT with cat delete pipes, Noweeds Exhaust Cutouts (extremely loud under full throttle), BTR Stage 3 Cam, BTR Platinum 660 Valve Spring Kit, TR7ix Iridium Spark Plugs, Lingenfelter Solid Isolator, 160 Degree Thermostat, Larger SC Coolant Reservoir with Hose Relocation Kit, BMR 1.25" Lowering Springs, MGW Short Throw Shifter, Racing Brake 2 piece rotors front and rear, Starkweather Performance Custom Dyno Tune on 91 Octane. 691.38 RWHP 630.35 RWTQ

04-10-2017, 10:46 AM	#5
runyonwc Drives: 2013 ZL1 Join Date: Sep 2015 Location: Orlando Posts: 39	I have a similar type of issue. I didnt really notice it before I installed my headers and had the car tuned. So Im not sure if it is a tune issue or what.

04-10-2017, 05:07 PM	#7
runyonwc Drives: 2013 ZL1 Join Date: Sep 2015 Location: Orlando Posts: 39	If it were a vacuum leak, why wouldn't it do it all the time? Why just while the car is rolling? My car does something similar to this while coming to a stop and the car is in neutral. I also have rotofab intake, headers (no cats), and a tune.