Occasionally doesn't start unless accelerator held down

Barnt · 03-07-2013, 01:16 PM

I'm sure this has been discussed somewhere but I haven't been able to find it yet. Can you point me in the direction of a helpful link?

Just recently my 05 wrx had a long crank to start, and then finally sputtered and caught after 3 or 4 tries. Drove 40 miles back home and it ran perfectly the entire way. Next morning it wouldn't start so I gave up after several tries cranking it and drove my truck to work. The next couple days it only started with the gas pedal held half way down and it took a few seconds but sputtered and started up and then ran perfectly. Thought at first I might have had some bad fuel but I filled it up (different station) and its still doing it.

My best guesses are:
-fuel pump going? (unlikely...?)
-clogged fuel filter (90k miles on it)
-bad fuel pressure regulator
-leaking fuel injectors (had happen on an 1990 Ford Bronco II)
-sticking idle air control valve? (this suggested by a friend)

130k miles, Cobb stg 1, I put in a new battery, sparkplugs, and airfilter less than 2000 miles ago

I have a new fuel pump and filter waiting for me at a dealership since I get OEM parts at dealer cost through a friend anyways

Any productive comments are much appreciated.
Thanks!

Uncle Scotty · 03-07-2013, 08:23 PM

clogged fuel filter??

change that first....

bad tank of fuel??

happen after a fill up??

Barnt · 03-08-2013, 04:34 PM

No, it was happening on about a quarter tank. I thought at first it may have been bad fuel so I filled up and it did not solve the issue. I'm changing the filter tomorrow. Hope that's it.

mod maniac · 03-09-2013, 12:41 AM

I fixed one that did that because of leaky injectors. I don't know if that is your problem but it fixed this customers car.

Barnt · 03-12-2013, 01:25 AM

Changed filter and pump. Problem persists...

jayman4312 · 03-12-2013, 03:20 PM

you changed the filter under the hood? or just the "sock" or "filter" that's on the pump.

ogboot · 03-12-2013, 03:41 PM

Can you hear the fuel pump prime when you insert the key and turn it on on (but do not start)?

Brock31 · 03-12-2013, 03:49 PM

I've had this happen before. Very intermittently (sp) maybe once every 2-3 months.

No other symptoms. Even after FP is primed, which I do at every start up.

Barnt · 03-13-2013, 04:26 PM

fuel pump is brand new. primes just fine.

and i was unaware of any underhood-filter for the wrx after 2004

fastnoypi · 03-13-2013, 08:31 PM

check the elbow behind the maf to the inlet, or the inlet to the turbo.
If any of the track is disconnected or have a large enough rip, you can have starting problems that you described.

Psychoreo · 03-13-2013, 08:38 PM

Having the accelerator pedal pushed to the floor used to engage "clear flood mode," I'm not sure when that stopped. It's possible you have a failing or stuck open injector that's pouring fuel and preventing it from running properly. If you have access to a stethoscope or long screw driver, place it on each injector while someone cranks it and see if you can hear them clicking.

Barnt · 03-14-2013, 12:55 PM

^^thanks I'll check on both of these this weekend. much appreciated.

Haelan · 03-14-2013, 09:01 PM

Quote:

Originally Posted by Barnt

^^thanks I'll check on both of these this weekend. much appreciated.

Pull the plugs and visually inspect if a cylinder is running rich (possible stuck injector). If holding the accelerator down helps to start then not enough air is getting passed the throttle plate, which could be the IACV--it acts as a throttle plate bypass.

03-07-2013, 01:16 PM	#1
Barnt Scooby Newbie Member#: 161824 Join Date: Oct 2007 Chapter/Region: MWSOC Location: Caledonia(Racine), Wisconsin Vehicle: 05 WRXwagon;PF01's OBP; S2k projector conv.	Occasionally doesn't start unless accelerator held down I'm sure this has been discussed somewhere but I haven't been able to find it yet. Can you point me in the direction of a helpful link? Just recently my 05 wrx had a long crank to start, and then finally sputtered and caught after 3 or 4 tries. Drove 40 miles back home and it ran perfectly the entire way. Next morning it wouldn't start so I gave up after several tries cranking it and drove my truck to work. The next couple days it only started with the gas pedal held half way down and it took a few seconds but sputtered and started up and then ran perfectly. Thought at first I might have had some bad fuel but I filled it up (different station) and its still doing it. My best guesses are: -fuel pump going? (unlikely...?) -clogged fuel filter (90k miles on it) -bad fuel pressure regulator -leaking fuel injectors (had happen on an 1990 Ford Bronco II) -sticking idle air control valve? (this suggested by a friend) 130k miles, Cobb stg 1, I put in a new battery, sparkplugs, and airfilter less than 2000 miles ago I have a new fuel pump and filter waiting for me at a dealership since I get OEM parts at dealer cost through a friend anyways Any productive comments are much appreciated. Thanks!

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03-07-2013, 08:23 PM	#2
Uncle Scotty NASIOC Supporter Member#: 16200 Join Date: Mar 2002 Vehicle: OK Houston we have an Uncle	clogged fuel filter?? change that first.... bad tank of fuel?? happen after a fill up??

03-08-2013, 04:34 PM	#3
Barnt Scooby Newbie Member#: 161824 Join Date: Oct 2007 Chapter/Region: MWSOC Location: Caledonia(Racine), Wisconsin Vehicle: 05 WRXwagon;PF01's OBP; S2k projector conv.	No, it was happening on about a quarter tank. I thought at first it may have been bad fuel so I filled up and it did not solve the issue. I'm changing the filter tomorrow. Hope that's it.

03-09-2013, 12:41 AM	#4
mod maniac NASIOC Supporter Member#: 300551 Join Date: Nov 2011 Chapter/Region: SCIC Location: mariposa ca. Vehicle: 2002 DD wgn 6 spd 2.1 kel 272's meth 2.5xtr	I fixed one that did that because of leaky injectors. I don't know if that is your problem but it fixed this customers car.

03-12-2013, 01:25 AM	#5
Barnt Scooby Newbie Member#: 161824 Join Date: Oct 2007 Chapter/Region: MWSOC Location: Caledonia(Racine), Wisconsin Vehicle: 05 WRXwagon;PF01's OBP; S2k projector conv.	Changed filter and pump. Problem persists...

03-12-2013, 03:20 PM	#6
jayman4312 Scooby Specialist Member#: 228784 Join Date: Nov 2009 Chapter/Region: MWSOC Location: Chicago, IL Vehicle: 2004 wrx black, stage 2+	you changed the filter under the hood? or just the "sock" or "filter" that's on the pump.

03-12-2013, 03:41 PM	#7
ogboot Scooby Specialist Member#: 170906 Join Date: Feb 2008 Chapter/Region: South East Vehicle: 2002 WRX psm	Can you hear the fuel pump prime when you insert the key and turn it on on (but do not start)?

03-12-2013, 03:49 PM	#8
Brock31 Scooby Specialist Member#: 128115 Join Date: Oct 2006 Chapter/Region: South East Location: Wilmington, NC Vehicle: 2004 4EAT Wagon PSM enginuity is cool	I've had this happen before. Very intermittently (sp) maybe once every 2-3 months. No other symptoms. Even after FP is primed, which I do at every start up.

03-13-2013, 04:26 PM	#9
Barnt Scooby Newbie Member#: 161824 Join Date: Oct 2007 Chapter/Region: MWSOC Location: Caledonia(Racine), Wisconsin Vehicle: 05 WRXwagon;PF01's OBP; S2k projector conv.	fuel pump is brand new. primes just fine. and i was unaware of any underhood-filter for the wrx after 2004

03-13-2013, 08:31 PM	#10
fastnoypi Scooby Specialist Member#: 6886 Join Date: May 2001 Chapter/Region: Tri-State Vehicle: MY01 EJ207 HTA35r nothing to see, i'm stock	check the elbow behind the maf to the inlet, or the inlet to the turbo. If any of the track is disconnected or have a large enough rip, you can have starting problems that you described.

03-13-2013, 08:38 PM	#11
Psychoreo Scooby Specialist Member#: 79643 Join Date: Jan 2005 Chapter/Region: NESIC Location: Torrington, CT Vehicle: 04 EJ207 Swapped Mikey tuned 271whp/287wtq	Having the accelerator pedal pushed to the floor used to engage "clear flood mode," I'm not sure when that stopped. It's possible you have a failing or stuck open injector that's pouring fuel and preventing it from running properly. If you have access to a stethoscope or long screw driver, place it on each injector while someone cranks it and see if you can hear them clicking.

03-14-2013, 12:55 PM	#12
Barnt Scooby Newbie Member#: 161824 Join Date: Oct 2007 Chapter/Region: MWSOC Location: Caledonia(Racine), Wisconsin Vehicle: 05 WRXwagon;PF01's OBP; S2k projector conv.	^^thanks I'll check on both of these this weekend. much appreciated.