Hello, E30 runs well except when trolling. It misses, stumbles and shakes. Fishing buddies even notice rough running. New plugs, yes indexed correctly. New computer software as of August 2018 during dealer visit, Fresh non-oxygenated fuel, set to XD100 oil injection.
I assume all inputs to fuel and air flow are electronically controlled? For example, no idle screws to adjust or blow out?