M6 hard starting

snackbar64 · 03-07-2017, 09:53 AM

Has anyone else experienced the starter spinning for several seconds before the car will start? Is this common? Rarely does the car ever fire right up. Almost thought it was out of gas and then VROOM!!!

mkorgan · 03-07-2017, 10:03 AM

Is this the first Direct injection car you have owned? DI cars are slower starting due to the priming process of the fuel system.

snackbar64 · 03-07-2017, 10:12 AM

Quote:

Originally Posted by mkorgan

Is this the first Direct injection car you have owned? DI cars are slower starting due to the priming process of the fuel system.

My 2013 fired right up. But I guess it's normal for this car.

WILWAXU · 03-07-2017, 10:12 AM

Not abnormal. My guess; it's a symptom of the push button start. The starter spins before the fuel pressure is up. With a key, the pump starts a split second before the starter engages, allowing fuel to pressurize the rails.

Ryephile · 03-07-2017, 10:17 AM

The long crank times has nothing to do with DI or push-button in general, otherwise every other DI and push button on the market would have the same "issue".

My hunch is it's priming the oil system prior to actually going into the crank fueling state. The crank times appear to be coolant and/or oil temp related. A warm LT1/LT4 engine fires much quicker than a cold one, and that's all in the calibration.

Until I do a datalog to prove or disprove this theory. You can rest assured however it's not a rule of thumb issue for DI or push button. This is a very intentional calibration by GM.

thompstl1 · 03-07-2017, 10:28 AM

Are you pressing on the accelerator during start-up? My 1LE (for example) won’t start at all under full throttle during cranking (part of the design).Pressing on the throttle (even a little) made it slow to start also.

NB2017ZL1 · 03-07-2017, 10:32 AM

Sounds perfectly normal

Ryephile · 03-07-2017, 10:33 AM

Quote:

Originally Posted by thompstl1

Are you pressing on the accelerator during start-up? My 1LE (for example) won’t start at all under full throttle during cranking (part of the design).Pressing on the throttle (even a little) made it slow to start also.

WOT during crank = flood clear = no injector pulsewidth.

You're not helping anything by having your foot on the pedal during cranking. It's not a carburetor, or even cable throttle. The ECU's got it handled.

*mlee* · 03-07-2017, 10:34 AM

Listen to this start up. Not me in the car and I haven't experienced it since, but will check back in if I do.

I haven't started it very many times either

snackbar64 · 03-07-2017, 10:39 AM

Quote:

Originally Posted by mlee

Listen to this start up. Not me in the car and I haven't experienced it since, but will check back in if I do.

I haven't started it very many times either

Yep that's it only mine goes a second or two longer before starting. Beautiful car. How many cartwheels have you done so far

Sven59 · 03-07-2017, 10:47 AM

My 5th gen starts immediately, always has. I don't touch the gas.

Ryephile · 03-07-2017, 10:48 AM

Quote:

Originally Posted by Sven59

My 5th gen starts immediately, always has. I don't touch the gas.

Different engine, different calibration.

Sven59 · 03-07-2017, 10:53 AM

Thanks

Ryephile · 03-07-2017, 11:10 AM

Quote:

Originally Posted by mlee

Listen to this start up. Not me in the car and I haven't experienced it since, but will check back in if I do.

I haven't started it very many times either

...

This sounds like a typical LT1/LT4 cold start to me.

Car looks amazing by the way, congrats!

03-07-2017, 09:53 AM	#1
snackbar64 Drives: SW 2017 ZL1, M6, Carbon, Nav, MR, Join Date: Dec 2012 Location: Prosper, TX Posts: 801	M6 hard starting Has anyone else experienced the starter spinning for several seconds before the car will start? Is this common? Rarely does the car ever fire right up. Almost thought it was out of gas and then VROOM!!!

03-07-2017, 10:12 AM	#4
WILWAXU Drives: 2019 Crush ZL1 1LE Join Date: May 2009 Location: League City, TX Posts: 544 View My Garage	Not abnormal. My guess; it's a symptom of the push button start. The starter spins before the fuel pressure is up. With a key, the pump starts a split second before the starter engages, allowing fuel to pressurize the rails. __________________ John Brown Instagram @wilwaxu Facebook @wilwaxu

03-07-2017, 10:17 AM	#5
Ryephile Hot Dog Drives: '17 1SS 1LE Join Date: Feb 2016 Location: Metro Detroit Posts: 1,937	The long crank times has nothing to do with DI or push-button in general, otherwise every other DI and push button on the market would have the same "issue". My hunch is it's priming the oil system prior to actually going into the crank fueling state. The crank times appear to be coolant and/or oil temp related. A warm LT1/LT4 engine fires much quicker than a cold one, and that's all in the calibration. Until I do a datalog to prove or disprove this theory. You can rest assured however it's not a rule of thumb issue for DI or push button. This is a very intentional calibration by GM. __________________ 2017 "M1SS1LE" in Hyper Blue w/PDR

03-07-2017, 10:28 AM	#6
thompstl1 Drives: 2017 A10 ZL1 Join Date: Mar 2014 Location: Anderson, Tx. Posts: 373 View My Garage	Are you pressing on the accelerator during start-up? My 1LE (for example) won’t start at all under full throttle during cranking (part of the design).Pressing on the throttle (even a little) made it slow to start also. __________________ Clear Bra, Tint, Splash Guards, Ceramic Coating, Painted Spoiler and Rear Views

03-07-2017, 10:32 AM	#7
NB2017ZL1 Drives: 2017 ZL1 10 Speed Hyper Blue Join Date: Jul 2016 Location: Canada Posts: 1,349	Sounds perfectly normal __________________ 2017 ZL1

03-07-2017, 10:03 AM	#2
mkorgan Drives: 1970-1/2 Z-28, 2017 ZL1 Join Date: Sep 2012 Location: Sanford, Fl Posts: 973	Is this the first Direct injection car you have owned? DI cars are slower starting due to the priming process of the fuel system.

03-07-2017, 10:47 AM	#11
Sven59 HAMMER PILOT Drives: 13 ZL1#182, 85 CJ7, 16 Silverado Join Date: Nov 2011 Location: Tucson AZ Posts: 4,387	My 5th gen starts immediately, always has. I don't touch the gas. __________________ "DO YOU WANT ME TO PUT THE HAMMER DOWN?"

03-07-2017, 10:53 AM	#13
Sven59 HAMMER PILOT Drives: 13 ZL1#182, 85 CJ7, 16 Silverado Join Date: Nov 2011 Location: Tucson AZ Posts: 4,387	Thanks __________________ "DO YOU WANT ME TO PUT THE HAMMER DOWN?"

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