Warm starts are now different with maggy. Is this normal - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Pollock · 05-17-2017, 11:13 AM

Now with the maggy. If the car is good and warm and I shut it off then go to start it say 1 to 2 hrs later... It cranks for a lot longer ( 2.5 to 5 sec) and does not just fire right up. The cylinders slowly start firing. Not all 8 at the same time if that makes sense.

If I shut it off for a few minutes it fires right up as it was cold.

This past weekend I noticed a lot of white smoke after a 2 hr sit time. I know white smoke is typically harmless. Just saying.

So I this just heat soak and the nature of the beast or could I have a potential problem?

mrimpala02 · 05-17-2017, 11:25 AM

This sounds like a tuning issue. There may be too much fuel dumping at start-up or not enough spark.

UNRIVALED SS · 05-18-2017, 07:03 AM

I would say you have one or more issues.

Could be something in the Tune. Don't know if you are running the one that magnuson provides or a custom.

White smoke vs grey vs black. White is often times some form or coolant or moisture. Not sure how that get into a LS cylinder with just a top mount supercharger install.

Without knowing any more details I would consider a tuning issue most likely or a fuel system that is leaking down and needs time to prime on startup.

Pollock · 05-18-2017, 03:49 PM

It was a dyno tune. I do have a fuel pressure gauge which reads 60 psi.
I sent a message to my tuner. Waiting for a response.

cc-rider · 05-18-2017, 06:55 PM

Mine does this too. It's in the tune. What's happening is that when it sits for a while, it gets heat soaked. I believe the IAT sensor reading goes sky high and the fueling isn't right for it then.

I tune myself but I've not bothered to figure this out yet. Your tuner will probably know how to do it. Either add or subtract fuel when it's really hot like that.

Pollock · 05-18-2017, 07:02 PM

Have you had any issues. Im not to concerned as long as it isnt causing harm.
Mike Norris did my tune.

cc-rider · 05-18-2017, 07:34 PM

No issues.

cc-rider · 05-18-2017, 07:41 PM

You may want to post this over in the tuning section of this forum. Some good Tuners hang out in there. Or post it over at the HP Tuners forum too. I know there's some table in the tune where add or subtract fuel to fix this. My guess is subtract. I think in a heat soaked engine that the air charge coming in for the start up is superheated (because the charger is connected to the engine really heats up from conduction) making for a low oxygen density charge and thus...a rich mixture making it stumble to get going. It's also why you see it dissapear almost immediately. There's only a small amount of superheated air inside the intake and charger. But unfortunately that's what is in there to get started. And it's much hotter than the air that used to sit inside the plastic LS3 intake.

Pollock · 05-18-2017, 07:58 PM

Thanks for the help and I cant tune nor do I have any business trying.
Since it wont hurt any thing. After my wheels and tires come. Provided I can get traction. Ill switch to a 3.4 pulley and address the tune then.

And yeah. If it was an old school carburator. Not sure if I would pump the throttle or hold it to the floor to get it to start quicker. Lmao. Seems lean to be honest.
But the heat soak makes sense after it starts it takes a 1 while to level out. Lmao.

supergt99 · 05-22-2017, 09:59 AM

I have this problem too and I believe it's in the tune. Just the other day I tried zl1 startup airflow and spark tables and it seemed to help. It's not perfect yet but definitly better. I'm going to try more cranking airflow when I get time.

2012LS3VERT · 05-25-2017, 01:32 PM

It is a combinination of cranking timing/fuel tuning that needs to be adjusted. The stock tables assume that the IAT sensor is in the intake tract, so when the sensor is relocated and gets heatsoaked, it pulls a lot of timing and adds fuel because it thinks the outside air temp is 175 degrees. I have adjusted this on several maggie cars to fix the problem, but dont have my laptop or I would post up which settings to change. The ZL1/ZR1 tables are somewhat better, but use an IAT2 sensor, so the primary IAT reading for cranking is still in the MAF sensor. Ill try to remeber to come back here and post up.

supergt99 · 05-25-2017, 01:39 PM

Quote:

Originally Posted by 2012LS3VERT

It is a combinination of cranking timing/fuel tuning that needs to be adjusted. The stock tables assume that the IAT sensor is in the intake tract, so when the sensor is relocated and gets heatsoaked, it pulls a lot of timing and adds fuel because it thinks the outside air temp is 175 degrees. I have adjusted this on several maggie cars to fix the problem, but dont have my laptop or I would post up which settings to change. The ZL1/ZR1 tables are somewhat better, but use an IAT2 sensor, so the primary IAT reading for cranking is still in the MAF sensor. Ill try to remeber to come back here and post up.

you would be my hero

Pollock · 05-26-2017, 05:43 PM

How do I tune myself? I have a lap top. Then what. Lol. My tuner didnt seem to make me feel like he could resolve the issue nor did he think it was a problem.

cc-rider · 05-26-2017, 08:43 PM

Buy HP Tuners. Get the Pro version ($600ish) and then invest another $150 in a good wideband and then the world is yours in terms of tuning.

Then go over to the tuner forum here...and the HP Tuners forum and read read read read. Then read some more. Then read some more. Then it will click.

Tuning has been some of the most fun I've had with my Camaro. I'm happy to help you out if needed.

05-17-2017, 11:13 AM	#1
Pollock LT4 M6 Drives: 2018 ZL1 1LE Join Date: Nov 2010 Location: Bloomington, IN Posts: 1,249	Warm starts are now different with maggy. Is this normal Now with the maggy. If the car is good and warm and I shut it off then go to start it say 1 to 2 hrs later... It cranks for a lot longer ( 2.5 to 5 sec) and does not just fire right up. The cylinders slowly start firing. Not all 8 at the same time if that makes sense. If I shut it off for a few minutes it fires right up as it was cold. This past weekend I noticed a lot of white smoke after a 2 hr sit time. I know white smoke is typically harmless. Just saying. So I this just heat soak and the nature of the beast or could I have a potential problem? Last edited by Pollock; 05-17-2017 at 11:28 AM.

05-17-2017, 11:25 AM	#2
mrimpala02 Drives: Black 2SS RS w/White Stripes Join Date: Mar 2011 Location: Katy, TX Posts: 775	This sounds like a tuning issue. There may be too much fuel dumping at start-up or not enough spark. __________________ 2010 2SS/RS "ChriSStine": Pat G Custom Turbo CamMotion Camshaft \| AGP TT BB Garrett 62/65's \| AGP/Fore Triple Pumps \| ID1700X Injectors \| Alky Control Twin Nozzle Meth \| Custom 3" Exhaust \| 3.27 gear set w/ Tru Trac \| McLeod Twin RXT \| Barton Short Throw Shifter \| 6th Gen ZL1 Wheels \| BMR 1.4" drop springs \| Pfadt rear trailing arms & tie rods \| Installed by Me & Tuned by Pat G

05-18-2017, 07:03 AM	#3
UNRIVALED SS Drives: 2010 Camaro SS Join Date: Aug 2010 Location: El Paso Posts: 704 View My Garage	Not normal I would say you have one or more issues. Could be something in the Tune. Don't know if you are running the one that magnuson provides or a custom. White smoke vs grey vs black. White is often times some form or coolant or moisture. Not sure how that get into a LS cylinder with just a top mount supercharger install. Without knowing any more details I would consider a tuning issue most likely or a fuel system that is leaking down and needs time to prime on startup.

05-18-2017, 03:49 PM	#4
Pollock LT4 M6 Drives: 2018 ZL1 1LE Join Date: Nov 2010 Location: Bloomington, IN Posts: 1,249	It was a dyno tune. I do have a fuel pressure gauge which reads 60 psi. I sent a message to my tuner. Waiting for a response.

05-18-2017, 06:55 PM	#5
cc-rider Drives: 2010 Camaro SS Join Date: Dec 2006 Location: MN Posts: 1,172	Mine does this too. It's in the tune. What's happening is that when it sits for a while, it gets heat soaked. I believe the IAT sensor reading goes sky high and the fueling isn't right for it then. I tune myself but I've not bothered to figure this out yet. Your tuner will probably know how to do it. Either add or subtract fuel when it's really hot like that.

05-18-2017, 07:02 PM	#6
Pollock LT4 M6 Drives: 2018 ZL1 1LE Join Date: Nov 2010 Location: Bloomington, IN Posts: 1,249	Have you had any issues. Im not to concerned as long as it isnt causing harm. Mike Norris did my tune.

05-18-2017, 07:34 PM	#7
cc-rider Drives: 2010 Camaro SS Join Date: Dec 2006 Location: MN Posts: 1,172	No issues.

05-18-2017, 07:41 PM	#8
cc-rider Drives: 2010 Camaro SS Join Date: Dec 2006 Location: MN Posts: 1,172	You may want to post this over in the tuning section of this forum. Some good Tuners hang out in there. Or post it over at the HP Tuners forum too. I know there's some table in the tune where add or subtract fuel to fix this. My guess is subtract. I think in a heat soaked engine that the air charge coming in for the start up is superheated (because the charger is connected to the engine really heats up from conduction) making for a low oxygen density charge and thus...a rich mixture making it stumble to get going. It's also why you see it dissapear almost immediately. There's only a small amount of superheated air inside the intake and charger. But unfortunately that's what is in there to get started. And it's much hotter than the air that used to sit inside the plastic LS3 intake.

05-18-2017, 07:58 PM	#9
Pollock LT4 M6 Drives: 2018 ZL1 1LE Join Date: Nov 2010 Location: Bloomington, IN Posts: 1,249	Thanks for the help and I cant tune nor do I have any business trying. Since it wont hurt any thing. After my wheels and tires come. Provided I can get traction. Ill switch to a 3.4 pulley and address the tune then. And yeah. If it was an old school carburator. Not sure if I would pump the throttle or hold it to the floor to get it to start quicker. Lmao. Seems lean to be honest. But the heat soak makes sense after it starts it takes a 1 while to level out. Lmao.

05-22-2017, 09:59 AM	#10
supergt99 Drives: 2013 Camaro SS 1LE Join Date: Oct 2014 Location: earth Posts: 288	I have this problem too and I believe it's in the tune. Just the other day I tried zl1 startup airflow and spark tables and it seemed to help. It's not perfect yet but definitly better. I'm going to try more cranking airflow when I get time.

05-25-2017, 01:32 PM	#11
2012LS3VERT Drives: 2012 2SSRS Vert, Black w/M6 Join Date: Jan 2013 Location: Montgomery, AL Posts: 1,265	It is a combinination of cranking timing/fuel tuning that needs to be adjusted. The stock tables assume that the IAT sensor is in the intake tract, so when the sensor is relocated and gets heatsoaked, it pulls a lot of timing and adds fuel because it thinks the outside air temp is 175 degrees. I have adjusted this on several maggie cars to fix the problem, but dont have my laptop or I would post up which settings to change. The ZL1/ZR1 tables are somewhat better, but use an IAT2 sensor, so the primary IAT reading for cranking is still in the MAF sensor. Ill try to remeber to come back here and post up.

05-26-2017, 05:43 PM	#13
Pollock LT4 M6 Drives: 2018 ZL1 1LE Join Date: Nov 2010 Location: Bloomington, IN Posts: 1,249	How do I tune myself? I have a lap top. Then what. Lol. My tuner didnt seem to make me feel like he could resolve the issue nor did he think it was a problem.

05-26-2017, 08:43 PM	#14
cc-rider Drives: 2010 Camaro SS Join Date: Dec 2006 Location: MN Posts: 1,172	Buy HP Tuners. Get the Pro version ($600ish) and then invest another $150 in a good wideband and then the world is yours in terms of tuning. Then go over to the tuner forum here...and the HP Tuners forum and read read read read. Then read some more. Then read some more. Then it will click. Tuning has been some of the most fun I've had with my Camaro. I'm happy to help you out if needed.