AFM & lower plenum seperated

[fobermueller]

Here in the North East my '81 928 would sit until spring when I would take her out. Each year it was harder to restart her until finally she would not start. Against better judgement and more due to frustration I tried starter fluid...a bit too much and I got a load bang. It would start but only run a few seconds. If I held the throttle plate open it would start but run rich...Went through rebuilding the injectors and noticed that while tracing the vacuum lines that the throttle body had separated.
However I noticed greasy grime on the bottom of the lower plenum which I cleaned out easily.

Question how far should I tear down the intake system to remove any grime? I managed to get a pencil camera up the TB and found a leaf on the throttle plate! If I remove the upper plenum I can get the camera down te runners