Starting the engine...

JDMSubaru · 08-14-2003, 03:09 AM

I have noticed an unusual phenomenon. I want to see if any other WRX owners have made note of them same, and if so, might any of you know what causes it?

I have noticed that in the morning when I start my car it will start incredibly fast (or any other time when the car hasn't been driven for at least 3 hours and the temperature reading shows to be at the bottom). But if I go do, say an errand or two, and start the car again after having just recently driven it, it will take considerably longer.

It's weird. Basically when the engine is totally cold it will start lightning fast. If it is hot it will take 3-4 times as long.

Has anyone else noticed this? Does anyone know what causes this?

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I am mattjk · 08-14-2003, 04:24 AM

Engine heat soak, and the cold start injection mode being off will cause that. It's a fairly normal phenomenon. Water temp is high, so the computer retards the timing more than when it's cold. Many other factors.

Austin · 08-15-2003, 02:21 PM

Be sure to turn your key to the ON position for 2-3 seconds before going to the START position to allow the fuel system to prime the rails.

US2JDM · 08-15-2003, 03:07 PM

Quote:

Originally posted by Austin
Be sure to turn your key to the ON position for 2-3 seconds before going to the START position to allow the fuel system to prime the rails.

True. The fuel pump needs to pressurize the system in those first couple of seconds.

I am mattjk · 08-15-2003, 03:12 PM

Wha?

The stock system stays pressurized for quite some time. All EFI fuel systems retain high residual fuel pressures, unless your check valve is leaking. This has been known to happen on WRX's.

Equilibrium Tuning · 08-15-2003, 04:21 PM

My WRX does the same thing. On cold start it fires right up but takes a couple cranks when its warm.

-- Ed

mr2guru · 08-16-2003, 09:52 PM

what kind of timing advance is the ecu trying during hot start? during cold start?

I am mattjk · 08-16-2003, 11:29 PM

Quote:

Originally posted by mr2guru
what kind of timing advance is the ecu trying during hot start? during cold start?

Hell if I know. I was just guessing. Ever try starting an old car with a distributor and no timing light? Starts right up when you advance the timing. I used to set the initial advance by ear... hehe

mr2guru · 08-17-2003, 12:20 PM

Hmmm I was just wondering. trying to setup a link and I am having trouble with starting. (~5 cranks before she fires up) I have messed with cold start enrichment, hot restart enrichment, crank enrichment...etc... but i haven't played with the timing down there. I believe it came preset at about 4-6 degrees over static in those fields. Just wondering if I should advance that or retard that.

mtb_dude · 08-23-2003, 11:44 PM

Hot start is an issue with many sports cars. Some old 911s just flat out won't crank when they are hot. They're also air cooled and "hot" to them is "H-O-T" to us.

JDMSubaru · 08-26-2003, 05:09 AM

I'm glad others here recognize this...I saw it as an odd phenomenon at first but then maybe realized that it might be due to the fact I have never owned a turbo car before.

fliz · 08-27-2003, 06:22 PM

Quote:

Originally posted by Austin
Be sure to turn your key to the ON position for 2-3 seconds before going to the START position to allow the fuel system to prime the rails.

I have the same experience. Mine starts slow if it's been sitting for 1-2 hours (stock ECU). If you turn the key to on, you can hear an electric motor whirring for a couple seconds (assuming you have the stereo off). I always try to wait for the whirring to stop before I crank the motor. It's still cranks more than a cold start, but better than just going from "Off" to "Start".

big_adventure · 08-28-2003, 12:42 AM

Like Fliz said, same thing here, but I'll take it a step further. My car ALWAYS starts faster if I turn it to "on" for 2-3 seconds first, then crank it. Cold, hot, whenever. It might take 0-2 cranks cold going straight to "start", or 0-1 cranks if I let it prime first.

It takes 2-3 cranks hot, and still 0-1 if I let it prime first.

FWIW...

Columbo · 06-18-2008, 06:15 PM

I have an '02 WRX and suspect the residual check valve is leaking down. Can someone direct me to where it is? A picture would help. The dealer was no help (no surprise). Is it easy to get at and change? Approx cost? THANKS!!

Columbo · 02-27-2010, 09:37 PM

Bump for information on the location of the residual check valve on an '02 WRX. There has to be one as stated further up on this thread.

Thanks!

08-14-2003, 03:09 AM	#1
JDMSubaru Visiting NASIOC Timeout Member#: 40546 Join Date: Jul 2003 Location: California	Starting the engine... I have noticed an unusual phenomenon. I want to see if any other WRX owners have made note of them same, and if so, might any of you know what causes it? I have noticed that in the morning when I start my car it will start incredibly fast (or any other time when the car hasn't been driven for at least 3 hours and the temperature reading shows to be at the bottom). But if I go do, say an errand or two, and start the car again after having just recently driven it, it will take considerably longer. It's weird. Basically when the engine is totally cold it will start lightning fast. If it is hot it will take 3-4 times as long. Has anyone else noticed this? Does anyone know what causes this? * Registered users of the site do not see these ads.

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08-14-2003, 04:24 AM	#2
I am mattjk * Banned * Member#: 36411 Join Date: May 2003 Location: I have my old screen name back Vehicle: I can be PM'd at "mattjk"	Engine heat soak, and the cold start injection mode being off will cause that. It's a fairly normal phenomenon. Water temp is high, so the computer retards the timing more than when it's cold. Many other factors.

08-15-2003, 02:21 PM	#3
Austin Scooby Guru Member#: 7089 Join Date: May 2001 Chapter/Region: NWIC Location: Moscow, ID Vehicle: 05 Legacy GT Sedan 07 4Runner Limited	Be sure to turn your key to the ON position for 2-3 seconds before going to the START position to allow the fuel system to prime the rails.

08-15-2003, 03:12 PM	#5
I am mattjk * Banned * Member#: 36411 Join Date: May 2003 Location: I have my old screen name back Vehicle: I can be PM'd at "mattjk"	Wha? The stock system stays pressurized for quite some time. All EFI fuel systems retain high residual fuel pressures, unless your check valve is leaking. This has been known to happen on WRX's.

08-15-2003, 04:21 PM	#6
Equilibrium Tuning NASIOC Vendor Member#: 26933 Join Date: Oct 2002 Chapter/Region: BAIC Location: Fairfield, CA Vehicle: 2006 STI CGM	My WRX does the same thing. On cold start it fires right up but takes a couple cranks when its warm. -- Ed

08-16-2003, 09:52 PM	#7
mr2guru Scooby Specialist Member#: 10334 Join Date: Sep 2001 Location: St. Louis Vehicle: 91 RX7 LSx swap '09 CC 3.6 4motion	what kind of timing advance is the ecu trying during hot start? during cold start?

08-17-2003, 12:20 PM	#9
mr2guru Scooby Specialist Member#: 10334 Join Date: Sep 2001 Location: St. Louis Vehicle: 91 RX7 LSx swap '09 CC 3.6 4motion	Hmmm I was just wondering. trying to setup a link and I am having trouble with starting. (~5 cranks before she fires up) I have messed with cold start enrichment, hot restart enrichment, crank enrichment...etc... but i haven't played with the timing down there. I believe it came preset at about 4-6 degrees over static in those fields. Just wondering if I should advance that or retard that.

08-23-2003, 11:44 PM	#10
mtb_dude Scooby Specialist Member#: 12619 Join Date: Nov 2001 Chapter/Region: Tri-State Location: LI, NY Vehicle: 02 WRX Wagon #47 SM w/RA gears	Hot start is an issue with many sports cars. Some old 911s just flat out won't crank when they are hot. They're also air cooled and "hot" to them is "H-O-T" to us.

08-26-2003, 05:09 AM	#11
JDMSubaru Visiting NASIOC Timeout Member#: 40546 Join Date: Jul 2003 Location: California	I'm glad others here recognize this...I saw it as an odd phenomenon at first but then maybe realized that it might be due to the fact I have never owned a turbo car before.

08-28-2003, 12:42 AM	#13
big_adventure Scooby Specialist Member#: 40501 Join Date: Jul 2003 Location: Paris, FR Vehicle: 2005 Decathalon 21sp One WheelSeanPower	Like Fliz said, same thing here, but I'll take it a step further. My car ALWAYS starts faster if I turn it to "on" for 2-3 seconds first, then crank it. Cold, hot, whenever. It might take 0-2 cranks cold going straight to "start", or 0-1 cranks if I let it prime first. It takes 2-3 cranks hot, and still 0-1 if I let it prime first. FWIW...

06-18-2008, 06:15 PM	#14
Columbo Scooby Newbie Member#: 17328 Join Date: Apr 2002 Location: Canyon Country, CA Vehicle: 2002 WRX Wagon 4EAT Appliance White	I have an '02 WRX and suspect the residual check valve is leaking down. Can someone direct me to where it is? A picture would help. The dealer was no help (no surprise). Is it easy to get at and change? Approx cost? THANKS!!

02-27-2010, 09:37 PM	#15
Columbo Scooby Newbie Member#: 17328 Join Date: Apr 2002 Location: Canyon Country, CA Vehicle: 2002 WRX Wagon 4EAT Appliance White	Bump for information on the location of the residual check valve on an '02 WRX. There has to be one as stated further up on this thread. Thanks!