Re: step motor?
Yes it shuts tight and is clean.
When I rev the engine manually, rotating the throttle valve by hand where the throttle cable sits, holding steady at mid rev range (~2500-5000) I can feel slight jolts coming from the valve and a subsequent dip in revs. Like the stepper motor is trying to correct the position of the valve.(?)
Spoke to my local independant and he said he had three more twin sparks like this recently, but no idea to the reason.
When I get some spare dosh I will get a new stepper, but the idle is steady and the problem is not so noticable when driving.