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
 

Photo
- - - - -

Stubborn misfiring continues 91 Legacy (cylindar 3)


  • Please log in to reply
6 replies to this topic

#1 DavieGravy

DavieGravy

    USMB Regular

  • Members
  • 138 posts
  • Northglenn, CO

Posted 24 May 2010 - 04:10 PM

Here's what I've done but the problem persists

New NGK spark plugs properly gapped
New spark plug wires
New coil pack
New ignitor
Checked for vacuum leaks
Cleaned MAF sensor
Cleared and pulled ECU codes (only one I'm getting is for the colant temp sensor)

I don't see how the colant temp sensor can cause a misfire, so I figured I'd try and replace the fuel injector. The cylindar is #3 (back passenger)

My question is, how do I replace the fuel injector? I removed the two screws, the electrical connector and the cap, but it won't come out. Do I need a puller of some sort? Can someone PLEASE give me quick, detailed instructions?

Thanks in advance.

#2 bheinen74

bheinen74

    Banned

  • Banned
  • Pip
  • 0 posts
  • central Iowa

Posted 24 May 2010 - 04:17 PM

first off, if you are even thinking about replacing the injector, you need to depressurize the fuel system in the rails first and foremost. In the trunk there is a access panel cover on the pasenger side with 4 screws to get to the fuel pump connector. remove cover, Unplug connector. then start car and let run until the car dies. When it dies, the fuel system has lost its pressure.

if you do not depressureize, all the fuel will leak into your cyclinder.
Oh, and to remove the injector, you need to twist on it and pull slightly. one of these works well
Posted Image

Edited by bheinen74, 24 May 2010 - 04:22 PM.


#3 johnceggleston

johnceggleston

    Lite Master of the Subaru

  • Gold Subscribers
  • 6,351 posts
  • Virginia

Posted 24 May 2010 - 04:59 PM

Cleared and pulled ECU codes (only one I'm getting is for the colant temp sensor)

I don't see how the colant temp sensor can cause a misfire, so I figured I'd try and replace the fuel injector. The cylindar is #3 (back passenger)


others will know more, but i would address the coolant temp sensor code first, then move on to whatever else. the code is there for a reason. the temp sensor can cause the engine to run too rich.

did you use subaru wires??

#4 WoodsWagon

WoodsWagon

    Formerly 91Loyale

  • Members
  • 3,945 posts
  • NH

Posted 25 May 2010 - 01:30 PM

Temp sensor is a good place to start, but it won't fix the missfire. I hate to say it, but cyl 3 seems the most susceptable to burnt valves. I would do a compression test to see what you have, and a leakdown test to see where it's going.

The injector on 3 is the last in the line of the fuel rail, and it seems to get clogged most often. That makes the cylinder run lean and burn up exhaust valves.

#5 heartless

heartless

    Do YOU Subaru?

  • Members
  • 2,746 posts
  • North Central Wisconsin

Posted 26 May 2010 - 07:15 AM

definitely depressurize the fuel system!! my car wont actually start after pulling the fuel pump connector, but cranking it over for a few seconds is usually sufficient to depressurize the system.

I found it easier to pull the entire rail when i changed my injectors (i did all 4 due to misfires on more than one cylinder) - gave me a little more room to work.

the injectors did not come out easily on mine - i had to both pull and pry gently around the edge. (a second pair of hands is always useful here). seems to me I gave each a little shot of PB Blaster to help loosen/lube up the O-rings - would not recommend doing this if the rail is still on the engine...

seating the new injector properly is made a little easier by giving the O-rings a VERY light film of engine oil - helps them slide into the rail without binding up

Good luck

#6 DavieGravy

DavieGravy

    USMB Regular

  • Members
  • 138 posts
  • Northglenn, CO

Posted 26 May 2010 - 07:36 PM

Thanks for the helpful advice. I'll try it and post back.

#7 DavieGravy

DavieGravy

    USMB Regular

  • Members
  • 138 posts
  • Northglenn, CO

Posted 29 May 2010 - 05:08 PM

Thanks everyone for the succinct advice. Replacing the fuel injector fixed the misfiring problem. I had a hell of a time trying to get the injector out of the fuel rail so I ended up replacing both passenger injectors and the rail itself (20 bucks from the junk yard). Strangely enough, the old fuel injectors had only one hole to squirt the fuel through whereas the new ones had three holes. Perhaps this was something subaru changed due to clogging problems.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users