I blocked all vacuum lines and bypassed everything in the cabin, Servo, EGR, even plugged the Brake Booster line; sprayed Carb Cleaner and Brakleen around everywhere. NOTHING. Then pulled the vacuum line from the HVAC/Cruise port on the throttle body and there was no noticeable vacuum from the port but there was vacuum from the line. That'* not right! The line I pulled out was hooked to the MAP sensor and tee-d into the Fuel Pressure Reg and drawing steady vacuum from the neighboring port. The real HVAC line was hooked to one side of the Vapor Canister if I remember right, so what I thought was pressure in the fuel tank must have been vacuum. Wow. I put the Purge Valve back on and hooked everything back up.
Tested on the 4-lane, by the road-side, & in the driveway. These are the things I noticed fixed:
1) Engine starts easy, idles right, doesn't want to die in gear.
2) Idle corrects properly at sudden stops.
3) Tranny shifts smoother.
4) Cruise control works.
5) SES light went out immediately.
6) Primary Cooling Fan come on for some reason?
7) BLM Cell went from the 70'* to 125 - rich condition gone - fuel savings returns!
Automotive excitement returns!
Erased codes before test driving. Checked afterwards and still have codes for low signal on the TPS and MAP. I couldn't get the SES light to come back on while testing though and engine performs more like normal. Punching the throttle is better, but a tiny, tiny bit slow to come back to idle - could be due to age. I'll have to check the EVAP system closer. Still have to figure out the P/N switch and maybe VSS. The list got shorter anyway.