2011 WRX Rough Idle/Misfire after driving

aTriz · 01-30-2013, 08:11 AM

I have a 2011 wrx and noticed that after I drive the car and it gets up to temp and turn it off go into the store/gas/etc. and come back out to start her up she has rough idle/misfire. After about 15-30 seconds of rough idling, the car runs perfectly fine after. I thought it was plugs because it was throwing the code for misfires in all cylinders but really need some help and input on what it could be. I just ordered new spark plugs and will be installing them this weekend but i'm hoping it's not worse? This all started I guess a few weeks after I went to e85 so maybe too much power for stock plugs? Please help me out fellas!

Mods
-Invidia catless downpipe
-grimmspeed ebc
-DW 1000cc injectors
-walbro fuel pump
-processwest TMIC
-e85 protuned

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rwfloberg · 01-30-2013, 10:14 AM

Miles? could be fouled. plugs should be changed around 30k I believe.

kabob.master · 01-30-2013, 10:26 AM

Quote:

Originally Posted by rwfloberg

Miles? could be fouled. plugs should be changed around 30k I believe.

Manual states 51k miles IIRC.

OP - could be due to many things. If I were you, I'd send a log to your tuner and see what he says.

aTriz · 01-30-2013, 10:36 AM

Only 18k miles

Tripintaz · 01-30-2013, 01:41 PM

You might need to have your cold/warm start fueling tables adjusted. If your tuner skipped over this part while tuning for E85 then start up issues are usually the result.

Kicnit · 01-30-2013, 02:42 PM

Quote:

Originally Posted by Tripintaz

You might need to have your cold/warm start fueling tables adjusted. If your tuner skipped over this part while tuning for E85 then start up issues are usually the result.

What Tripintaz said ^^. I've never experience this exact problem, but I have a buddy that has. It was exactly what was mentioned above. We live in New England, and it started being an issue once the temps dropped to 40's or lower.

cheers,
kyle

aTriz · 01-30-2013, 05:18 PM

Thanks fellas i'll email my tuner tonight and i'll keep it updated

aTriz · 01-31-2013, 05:38 PM

https://docs.google.com/spreadsheet/...Xc&hl=en#gid=0

100% fuel pump duty at idle? I think maybe something to do with that, considering it goes to 33% when the rough idle stops. Maybe fuel pump is leaking or something no clue.

kabob.master · 02-01-2013, 12:23 AM

What did your tuner say?

dsm_luck · 02-02-2013, 07:07 PM

I have had this same issue in the past. Rough idle when engine is warm for about 30 seconds. If I let it sit it will smooth out. If I try to drive right after warm start it will every once in a while throw a misfire cel. I am sure it has to with cranking or startup tables. On the plus side with my modified cranking tables I have been able to one crank start my car on 100% E85 at 20 degrees.

aTriz · 02-02-2013, 08:09 PM

^^ yep dsm exactly,

I talked to my tuner he said there is too much fuel on hot crank, but this is also an indicator of the plugs are on the way out.

So he's gonna adjust my map and I will be installing plugs next week!

2011boostdwrx · 02-03-2013, 01:04 AM

just had thison my highly modded 11, but mine did it only at idle, was the FPR.

01-30-2013, 08:11 AM	#1
aTriz Scooby Newbie Member#: 95202 Join Date: Sep 2005 Chapter/Region: South East Location: South FL Vehicle: 2011 WRX PhatBotti e85 Tuned	2011 WRX Rough Idle/Misfire after driving I have a 2011 wrx and noticed that after I drive the car and it gets up to temp and turn it off go into the store/gas/etc. and come back out to start her up she has rough idle/misfire. After about 15-30 seconds of rough idling, the car runs perfectly fine after. I thought it was plugs because it was throwing the code for misfires in all cylinders but really need some help and input on what it could be. I just ordered new spark plugs and will be installing them this weekend but i'm hoping it's not worse? This all started I guess a few weeks after I went to e85 so maybe too much power for stock plugs? Please help me out fellas! Mods -Invidia catless downpipe -grimmspeed ebc -DW 1000cc injectors -walbro fuel pump -processwest TMIC -e85 protuned * Registered users of the site do not see these ads. Last edited by aTriz; 01-30-2013 at 08:17 AM.

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01-30-2013, 10:14 AM	#2
rwfloberg Scooby Newbie Member#: 327538 Join Date: Jul 2012 Chapter/Region: MAIC Location: White Marsh & La Plata MD Vehicle: 2012 WRX Stage 2+ SWP	Miles? could be fouled. plugs should be changed around 30k I believe.

01-30-2013, 10:36 AM	#4
aTriz Scooby Newbie Member#: 95202 Join Date: Sep 2005 Chapter/Region: South East Location: South FL Vehicle: 2011 WRX PhatBotti e85 Tuned	Only 18k miles

01-30-2013, 01:41 PM	#5
Tripintaz Scooby Specialist Member#: 245218 Join Date: Apr 2010 Chapter/Region: South East Location: FL Vehicle: 2013 STI Limited Ice Silver	You might need to have your cold/warm start fueling tables adjusted. If your tuner skipped over this part while tuning for E85 then start up issues are usually the result.

01-30-2013, 05:18 PM	#7
aTriz Scooby Newbie Member#: 95202 Join Date: Sep 2005 Chapter/Region: South East Location: South FL Vehicle: 2011 WRX PhatBotti e85 Tuned	Thanks fellas i'll email my tuner tonight and i'll keep it updated

01-31-2013, 05:38 PM	#8
aTriz Scooby Newbie Member#: 95202 Join Date: Sep 2005 Chapter/Region: South East Location: South FL Vehicle: 2011 WRX PhatBotti e85 Tuned	https://docs.google.com/spreadsheet/...Xc&hl=en#gid=0 100% fuel pump duty at idle? I think maybe something to do with that, considering it goes to 33% when the rough idle stops. Maybe fuel pump is leaking or something no clue.

02-01-2013, 12:23 AM	#9
kabob.master Scooby Specialist Member#: 258791 Join Date: Sep 2010 Chapter/Region: SCIC Location: CA Vehicle: 2011 wrx 5dr lmtd. 299awhp / 322tq @ 17.6psi	What did your tuner say?

02-02-2013, 07:07 PM	#10
dsm_luck Scooby Newbie Member#: 322645 Join Date: Jun 2012 Location: Broomfield, Colorado Vehicle: 2012 WRX	I have had this same issue in the past. Rough idle when engine is warm for about 30 seconds. If I let it sit it will smooth out. If I try to drive right after warm start it will every once in a while throw a misfire cel. I am sure it has to with cranking or startup tables. On the plus side with my modified cranking tables I have been able to one crank start my car on 100% E85 at 20 degrees.

02-02-2013, 08:09 PM	#11
aTriz Scooby Newbie Member#: 95202 Join Date: Sep 2005 Chapter/Region: South East Location: South FL Vehicle: 2011 WRX PhatBotti e85 Tuned	^^ yep dsm exactly, I talked to my tuner he said there is too much fuel on hot crank, but this is also an indicator of the plugs are on the way out. So he's gonna adjust my map and I will be installing plugs next week!

02-03-2013, 01:04 AM	#12
2011boostdwrx Scooby Specialist Member#: 263470 Join Date: Nov 2010	just had thison my highly modded 11, but mine did it only at idle, was the FPR.