1998 Legacy GT, that came with the 2.5, but currently has a turbo 2.0 block(JDM 91 EJ20, no turbo, factory 2.5 NA manifold, wiring, etc).  The problem stayed with the car, after I swapped the block, so I know it's not block related.

 

When the ambient temp is cool, the car is usually fine.  But once it gets warm out, like it is now, I get misfires when the car is hot, after I turn it off and let it sit for a short period of time.  I have also gotten flashing CELs, more so when it is warm/hot ambient temp.  I recently got a job delivering pizza, which has made the problem that much more noticeable(a lot of on/off with the engine fully warmed up).  So I have to get this fixed.

 

The coilpack tests within specs (~0.7 primaries, ~14k secondaries).  Crank, cam, and knock sensors have been swapped out with junkyard ones, with no change in behavior.  I have gotten codes for all 4 cylinder misfires, but no other codes present.  The last one had freeze frame data of 177F temp, 87% load.  It usually doesn't throw a code at idle when I fire it up, but it runs incredibly rough.  I can often feel 1 or 2 cylinders not firing properly.  If I rev the engine, they will start firing correctly, and then be fine the rest of the time the engine is running.  I cleaned the IAC today, and put a new gasket on.  Didn't change anything. I have also verified the timing belt position several times.

 

Last summer, during 90+ ambient temps, there was at least one time the car would NOT start after sitting about 30 minutes.  It fired a few times, but wouldn't turn over.  After I let it sit for another hour or so, it finally started up, but ran really rough at first.  This was on the 2.5 block.

Edited April 30, 201312 yr by Speedwagon

Replace the coil pack and see what happens.

I see nothing about a good old fashioned tune up. Forget the coil pack suggestion. Start with plugs, OE wires, filters and a PCV valve first.

I see nothing about a good old fashioned tune up. Forget the coil pack suggestion. Start with plugs, OE wires, filters and a PCV valve first.

 

The PCV valve is new(only a few months old).  I don't recall exactly when I replaced the plugs and wires, but they aren't that old, and I didn't go cheap on them.  NGK wires, and NGK plugs.  I forget exactly what plugs are in there though.

Pull the plugs again. See what they look like. Check the wire boots for oil contamination.

 

This can be a failing coil after a heat soak (hot) but i want to rule out the other things first

I'll check that out.

 

Also, forgot to mention above: There are times when the CEL will flash for a few seconds, and other times when it keeps on flashing for 30ish seconds.  And nothing I do seems to change it when it is flashing that long(accel, decel, steady).  I don't recall ever feeling any misfires when it is doing this.

Edited April 30, 201312 yr by Speedwagon