Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Reply
 
LinkBack Thread Tools Display Modes
Old 10-01-2013, 12:33 AM   #1
Registered User
 
Join Date: Jul 2011
Location: so cali
Posts: 302
Random Misfire of 2, 4, 6

Had a random misfire the other day while sitting at a traffic light. Check engine flashed for a few seconds and a little jitter, gave it gas and everything was back to normal and check engine light even went away.

Plugged in my reader and said it was a random misfire of 2,4,6. I was planning on changing my plugs this weekend anyways because I think it's about time.

Anything else I should check? Any reason why all of the driver side misfired at once?

Thanks

ohhh my is offline   Reply With Quote
Old 10-01-2013, 12:37 PM   #2
Certified Boxster Addict
 
Join Date: Nov 2010
Location: Los Angeles
Posts: 7,505
Left-side misfire? Some might say happens every day in the White House.

Ok, joking aside, there are four primary causes of engine misfires - a loss of spark, an unbalanced air/fuel ratio, a faulty fuel injector or fuel supply, and a loss of compression. Obviously, there are a lot of components to consider. I'd change the plugs and see if you get a repeat.

If you do get a repeat, then look for components that are common to all of the left side cyls: left side intake plenum vacuum leak, left side fuel rail, left side exhaust leak or failed cat, etc.
__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
thstone is offline   Reply With Quote
Old 10-01-2013, 01:06 PM   #3
Registered User
 
BYprodriver's Avatar
 
Join Date: Oct 2008
Location: O.C. CA
Posts: 3,268
Garage
Cyl.#2 is middle passenger side. Firing order is: 1-6-2-4-3-5, so why did 3 cyl in a row misfire? As you remove sparkplugs inspect closely for variances that might give a clue.
BYprodriver is offline   Reply With Quote
Old 10-01-2013, 03:00 PM   #4
Registered User
 
Join Date: Jul 2011
Location: so cali
Posts: 302
Quote:
Originally Posted by thstone View Post
Left-side misfire? Some might say happens every day in the White House.

Ok, joking aside, there are four primary causes of engine misfires - a loss of spark, an unbalanced air/fuel ratio, a faulty fuel injector or fuel supply, and a loss of compression. Obviously, there are a lot of components to consider. I'd change the plugs and see if you get a repeat.

If you do get a repeat, then look for components that are common to all of the left side cyls: left side intake plenum vacuum leak, left side fuel rail, left side exhaust leak or failed cat, etc.
Thanks for the detailed reply and places to check. I understand and know where to locate all of them, but where would the left side fuel rail be located and how would I check that?

Quote:
Originally Posted by BYprodriver View Post
Cyl.#2 is middle passenger side. Firing order is: 1-6-2-4-3-5, so why did 3 cyl in a row misfire? As you remove sparkplugs inspect closely for variances that might give a clue.
Middle passenger side? I thought all the even are on the drive side from front to back 2, 4, 6... but thanks for the firing order, you're right not only was it all on one side, but all in a row 6, 2, 4.. weird.
ohhh my is offline   Reply With Quote
Old 10-01-2013, 03:47 PM   #5
Registered User
 
BYprodriver's Avatar
 
Join Date: Oct 2008
Location: O.C. CA
Posts: 3,268
Garage
Middle passenger side? I thought all the even are on the drive side from front to back 2, 4, 6... but thanks for the firing order, you're right not only was it all on one side, but all in a row 6, 2, 4.. weird.[/QUOTE]


#2 on pass side middle, #4 is driver side front, #6 is driver side rear. To maintain balance you have to fire one side then the opposite side.
BYprodriver is offline   Reply With Quote
Old 10-01-2013, 06:07 PM   #6
Certified Boxster Addict
 
Join Date: Nov 2010
Location: Los Angeles
Posts: 7,505
Quote:
Originally Posted by ohhh my View Post
... but where would the left side fuel rail be located and how would I check that?
Fuel rail is the gold colored tube in the middle of the photo. Check fuel pressure and flow.

__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
thstone is offline   Reply With Quote
Old 10-02-2013, 10:49 PM   #7
Registered User
 
Join Date: Jul 2011
Location: so cali
Posts: 302
edited.....

ohhh my is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 11:31 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page