post a picture of your ICS.
Looks like you have alot of original water hoses and such. Maybe the ICS wasn't replaced?????
I've never worked on an '89 that had the "central heater" on the T.B. That was a "recall" item added. It is needed for really cold and especially for really damp condition back east.
Where you live,,I would eliminate it to get rid of extra water hoses and get rid of that rubber gasket thingy.
A small ammount of Silicone should be OK on the rubber gasket, just don't get any near the trottle body vacuum passages on the T.B.
I really want to see you get this thing going. Sierra snow will be in your back yard soon.
Again, please put a pic. of you ICS,,,I still think that s your problem and your chacing phatoms, waisting money and losing valuble time that should be spent 4 wheeling.

dave h.
'89 Raider V6 5spd;Aisin Hubs;; Gen2 LS: frt. brakes, rear coils;U.C.arms;R.trailing arms;idler arm; rear LSD axle w.disc brakes ;2 battery system for Dog's fan; relocated ECU; custom bumpers;J.Baker receiver;Conferr roofrack; t-bar crank.