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

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

No

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?

 

Larry

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.

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.

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