Mechanics

ROUGH IDLE

1997 Subaru Outback

Engine Performance problem
1997 Subaru Outback 4 cyl All Wheel Drive Automatic 185000 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!
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Alaskabruce
July 25, 2010.




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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Mhpautos
Jul 25, 2010.
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.

Tiny
Alaskabruce
Jul 25, 2010.
OK, I will give it some thought and I will get back to you soon.

Mark (mhpautos)

Mhpautos
Jul 25, 2010.

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