Jump to content

Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse

- - - - -

99 Impreza OBS 2.2 PO304, Miss fire on #4 Cylinder

  • Please log in to reply
6 replies to this topic

#1 lmdew



  • Members
  • 3,775 posts
  • Colorado Springs

Posted 11 February 2013 - 08:14 PM

The Daughters OBS was running a little rough off idle the last time she was down.  Now she has a miss fire on #4.  I did do Seafoam in the Intake and a Lucas Gas Treatment in the Tank the last time she was down.  Plugs have been changed to NGK copper core.  Going to have the #1 son swap the plug wires side to side and see if the fault follows.  


If an injector was leaking the plug would be fouled.  I have not seen the plugs, so hard to tell.


Valve Cover gaskets and the Spark plug tube seals were changed about a year ago. 


140+ K miles.


Other ideas?


Thanks, Larry

#2 ShawnW


    Subaru Master Technician

  • Administrator
  • 12,955 posts
  • Denver, Colorado

Posted 11 February 2013 - 08:22 PM

Has she had anybody other than you or your son work on it?  

#3 lmdew



  • Members
  • 3,775 posts
  • Colorado Springs

Posted 11 February 2013 - 08:23 PM


#4 lmdew



  • Members
  • 3,775 posts
  • Colorado Springs

Posted 12 February 2013 - 05:29 PM

I'm away from my garage, is the valve clearance set with the screw and jam nut on the 99 2.2.  


Thinking the valve may be slightly open.  I did clean the system with seafoam and lucas fuel system cleaner.  Could have cleaned the carbon off the valves?



#5 Fairtax4me



  • Members
  • 13,034 posts
  • Charlottesburg, VA

Posted 12 February 2013 - 05:52 PM

Yes, lash clearance is adjustable with a screw on the rocker. Wouldn't think valve clearance should be an issue, but if they've never been adjusted its possible.

#6 lmdew



  • Members
  • 3,775 posts
  • Colorado Springs

Posted 14 February 2013 - 11:45 PM

Coil was corroded on 2 of the 4 terminals.  Swapped the Coil and plug wires, new NGK copper core plugs and it's operating on all 4 cylinders again but still stumbles when you have 25-50% throttle in.  No codes but the plugs are very rich. 


Going to check the TPS, MAF, O2 and Knock sensor.

#7 lmdew



  • Members
  • 3,775 posts
  • Colorado Springs

Posted 17 February 2013 - 07:21 PM

Son had another coil from his buddy's car.  4 pin connector.  It started running on all 4 but then would not rev above 2500.  Very Strange.  I went up today, bolted on a use Subaru Coil I had, Problem Solved.  Lessons learned, Only use Subaru Coils and NGK or Subaru Plug wires.


Back on the road.  Thanks Larry

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users