Cold start engine rpm rise is gone ?? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Farm · 03-21-2017, 08:24 PM

I need a little help. My car ( 2013 1LE) is acting up. The last few times I drove it last fall things were different. When I cold start the car it doesn't do the normal high rpm rev in the beginning. It instantly goes straight to the warmed up slow sounding idle. It also seems to be idling a little slower, 50-100 rpm less. It drives different also, needs more throttle when starting off the line. Seems easier to kill than normal. Car seems to buck a little bit when cruising in low rpm's. It acts normal for the most part when rowing through the gears.

I have a friend that is a diesel mechanic. He has a snap on scanner that we can check the car with. What things should we look for ??? I live in southeast Iowa and don't have any shops remotely close that I trust to check the car. Dealership is out of the question. Car is about as modded as it can get still being naturally aspirated.

Thanks in advance !!

dreksnot · 03-21-2017, 09:33 PM

What do you mean by "modded?" Cam? If so, then airflow and fuel are big time factors to how the car is going to run. Sounds like you need more Minimum Idle Airflow, and some higher values in the Start-up Airflow tables. But I'm saying this off of the cuff. Your tuner should have corrected these tables when installing the parts, of if you installed, then you should really have a competent tuner tune the car. And, by competent, I mean someone who knows LS3/L99 motors well, and doesn't rush the job just to get paid. They do it right, and right the first time.

Farm · 03-21-2017, 10:07 PM

I should have clarified my post a little better ! The modifications on the engine were done years ago. It was then Dyno tuned. The car has drivin perfect up until late last fall. I did no work on the car between running great and running rough. Then something changed. I'm hoping it's just a sensor or something that failed. Sorry for the confusion.

KY1LE · 08-04-2018, 08:16 AM

Quote:

Originally Posted by Farm

I should have clarified my post a little better ! The modifications on the engine were done years ago. It was then Dyno tuned. The car has drivin perfect up until late last fall. I did no work on the car between running great and running rough. Then something changed. I'm hoping it's just a sensor or something that failed. Sorry for the confusion.

Did you figure out your issue? I'm having the same problem.

Farm · 08-05-2018, 08:32 AM

Old fuel was my problem. Drained the fuel out of the car, put in fresh 91 ethanol free. Problem went away. The car only gets a couple tanks run threw it per year. When storing the car in winter I keep it almost empty and dump in a 5 gallon can of prepackaged VP 91 octane ethanol free 4 cycle fuel. My car sits in a climate controlled garage so I don't worry about condensation in the tank. Lol

03-21-2017, 08:24 PM	#1
Farm Drives: 2013 2SS/RS 1LE Join Date: Nov 2014 Location: Iowa Posts: 23	Cold start engine rpm rise is gone ?? I need a little help. My car ( 2013 1LE) is acting up. The last few times I drove it last fall things were different. When I cold start the car it doesn't do the normal high rpm rev in the beginning. It instantly goes straight to the warmed up slow sounding idle. It also seems to be idling a little slower, 50-100 rpm less. It drives different also, needs more throttle when starting off the line. Seems easier to kill than normal. Car seems to buck a little bit when cruising in low rpm's. It acts normal for the most part when rowing through the gears. I have a friend that is a diesel mechanic. He has a snap on scanner that we can check the car with. What things should we look for ??? I live in southeast Iowa and don't have any shops remotely close that I trust to check the car. Dealership is out of the question. Car is about as modded as it can get still being naturally aspirated. Thanks in advance !!

03-21-2017, 09:33 PM	#2
dreksnot Served USN - Atomic Chimp Drives: 13 Camaro LSX434 TT M6, 21 ZLE A10 Join Date: Jul 2012 Location: Fort Collins, CO Posts: 1,603 View My Garage	What do you mean by "modded?" Cam? If so, then airflow and fuel are big time factors to how the car is going to run. Sounds like you need more Minimum Idle Airflow, and some higher values in the Start-up Airflow tables. But I'm saying this off of the cuff. Your tuner should have corrected these tables when installing the parts, of if you installed, then you should really have a competent tuner tune the car. And, by competent, I mean someone who knows LS3/L99 motors well, and doesn't rush the job just to get paid. They do it right, and right the first time. __________________ In excess of 1,000WHP LSX434 \| AGP 65/65 TT \| BTR Equalizer Intake \| Trickflow 245cc cathedral \| BTR custom cam \| Cortex EBC \| n2mb WOT \| ID-1700x \| Brisk GR12S \| RPM Lv 7 TR6060 \| AGP's Triple 525LPH Fore Fuel \| Monster LT1-S Triple \| 4.11 DSS Proform 9", CF driveshaft, 1400hp axles \| Hurst Line Lock \| MGW Retro Short Throw w/old skool Hurst T-handle \| ADM solid subframe mounts \| Prothane Motor Mounts \| Revshift Poly Trans insert \| Moreno camber/caster plates

03-21-2017, 10:07 PM	#3
Farm Drives: 2013 2SS/RS 1LE Join Date: Nov 2014 Location: Iowa Posts: 23	I should have clarified my post a little better ! The modifications on the engine were done years ago. It was then Dyno tuned. The car has drivin perfect up until late last fall. I did no work on the car between running great and running rough. Then something changed. I'm hoping it's just a sensor or something that failed. Sorry for the confusion. Last edited by Farm; 03-21-2017 at 10:16 PM. Reason: Spelling

08-05-2018, 08:32 AM	#5
Farm Drives: 2013 2SS/RS 1LE Join Date: Nov 2014 Location: Iowa Posts: 23	Old fuel was my problem. Drained the fuel out of the car, put in fresh 91 ethanol free. Problem went away. The car only gets a couple tanks run threw it per year. When storing the car in winter I keep it almost empty and dump in a 5 gallon can of prepackaged VP 91 octane ethanol free 4 cycle fuel. My car sits in a climate controlled garage so I don't worry about condensation in the tank. Lol