Fuel Pressure Regulator Connection

try disconnecting a few things on the plenum to see if there is a difference, a solenoid in one of the air control valves might be stuck open, you might have your aircon engaged etc, just have a fiddle around, cause theres no way with the throttlebody closed and no auxillary valves open that itll idle that high, theres too much crap on the plenum stock i reckon im making block off plates for a few things when i get the time to go get some 3mm plate for it

I'm running a GM 165 Amp alternator, so any change is hardly noticably. The engine is rebuilt which might help.

i ran a 85 na with stock ecu, block off plates and deletes, never plugged the O2 in, ran fine, got 30mpg hiway, 16 city. no idle or cruising issues. my 87t harness doesnt even have the yellow wire that runs from the O2 back to pin 115. car ran fine.