[AllHailKingVolvo]

Thanks Dave and Tony!

Did a bit more sleuthing this afternoon, the intake manifold bolts are all drum tight and there is no air ingress via the gasket or injectors (tested with carb cleaner) all injector solenoids are happily clicking away and all seems content in that regard.

BUT...the throttle position switch doesn’t appear to be working. It’s not clicking, and the car runs identically whether it’s plugged in or unplugged. No note or running texture change when it’s unplugged with the engine running. Idles identically (slightly lumpy as per usual) and revs identically.

I’m now wondering if the TPS is shot, obviously. Would a failed TPS leave the IAC valve open at all times, causing the MAF to be confused and the engine to lean out excessively?