Maybe see if ....
Throttle butterfly is returning properly, check the plug/wiring to the throttle position sensor (black box on the throttle body) , check grey engine loom plugs.
let it idle and spray some electrical cleaner around the vac and boost pipes to see if the idle rises to locate a leak .
If it's not any of those best bet would be a auto electrician preferably with a bit of experience with scoobs