Rapidcrazy

Out of my scope really, but could be your idle air control valve, if that's playing up it will give you issues with idle, especially if the engine gets loaded up a little as the valve may not be letting enough air through, hence it tries to stall. I know you said vacuum leaks are out, but check if any air is getting pulled in after the MAF, if you imagine the air filter creates a bit of a restriction and this can cause a slight vacuum in the intake even before the throttle, and if unmetered air gets in you could be running lean, and this could only give issues when idling, Just ideas for food, or thought or what ever the saying is, either way I'm hungry.

I cant find excatly where I got the clearances, but it was in a subaru service manual, what I wrote in my book Rotor tips std 0.04 - 0.14 max 0.18mm Outer rotor to body 0.02 - 0.07 max 0.15mm Rotor height to bolt on cover (can measure this with a staight edge) 0.1 - 0.175 max 0.2mm Mine was just under the std upper limit with no visable damage, so good enough for me They just did the work mentioned and it was $475, I checked the journals myself I just got the bill for my heads today, strip and clean, regrind/cut the valves, then reset the valve lash and install new stem seals on reassembly, and surfacing, boths head it was $1200 And Ive spent about $730 at rock auto for bearings, rings, timing kit, full gasket kit and a couple little extra bits! Hope thats helps

Im in the process of rebuilding my first ej20 at the moment, its not done so I cant say what Ive done works, Im mentally prepared for it to pop on the first drive =] I ran a bearing, so I bought a donor motor and had the block cleaned and decked, with a light hone for the new rings, Im sticking with the stock pistons and rods that were in it, just new bearings and rings, and a complete gasket kit, all parts are from rockauto, and Im reusing my stock oil pump because the clearances were ok, Its just a project car so Ive been taking my time and its quite enjoyable, learning alot too, Im up to the head rebuild now, but ive passed that part to a recon shop, If i can help with any questions let me know!

How are you getting on with this, swamp?