1997 Subaru Outback rough idle

Tiny
ALASKABRUCE
  • MEMBER
  • 1997 SUBARU OUTBACK
  • 4 CYL
  • AWD
  • AUTOMATIC
  • 185,000 MILES
My 97 outback 2.5 has been exhibiting rough idle for almost a year now. It starts fine, runs well otherwise, plenty of power, and is getting mid-20's mpg. No oil burning, 165-170 compression on all cylinders, good consistent vacuum readings. Have replaced plugs, wires, coil. Codes show misfire on #1 & 2 cyls. I have also recently replaced the fuel pump, and tried swapping injectors around, but the rough idle remains. Not sure what else to look for. Thanks for any suggestions!
Sunday, July 25th, 2010 AT 5:36 PM

3 Replies

Tiny
MHPAUTOS
  • MECHANIC
  • 31,937 POSTS
Hi there,

Thank you for the donation,

I would next be checking for a vacuum leak around those cylinders, I do see that you say the vacuum readings are ok, but I still would try a tin of starter fluid and just spray a little around the manifold at those cylinders, if a small leak is there, the revs will increase, try this next.

Mark (mhpautos)
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Sunday, July 25th, 2010 AT 7:17 PM
Tiny
ALASKABRUCE
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  • 2 POSTS
Forgot to mention it but that was also one of the first things I tried, no apparent vacuum leaks anywhere, even checked all lines for possible cracks/splits that would be opening up once engine warmed up, etc.
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Sunday, July 25th, 2010 AT 8:01 PM
Tiny
MHPAUTOS
  • MECHANIC
  • 31,937 POSTS
OK, I will give it some thought and I will get back to you soon.

Mark (mhpautos)
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Sunday, July 25th, 2010 AT 8:09 PM

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