Another 156 idling post, yay
Engine hunts, sometimes sits constantly at 2-3000 rpm. Its like a more aggressive version of what you get if you haven't cleaned the butterfly.
I gave the throttle a good clean anyway, cleaned the airflow sensor in the air intake, and did the 90secs at position 2, 90secs off, start-it-and-thrash-it throttle reset, but the problem remained.
Google suggested I replace the throttle idle motor (stepper motor) so I picked one up. With the replacement on, the engine goes straight to 5k and sits there. Swapped back to the original, and we're back at the erratic idling again. I tried a second (new) idler motor and we're back to 5k rpm again. So, I'm on the original idle motor and still have the tickover issue.
(the replacement stepper motors I picked up were Bosch original kit and seemed identical, btw).
Is there a separate throttle position sensor on the throttle? Could that be the issue? Any help would be much appreciated.
On the plus side, its only ever a problem if I go slow or stop.