Oh well, there goes that theory. Air regulator seems OK.
So the engine: won't idle properly when cold, is sluggish to 3500rpm, has a 'slight miss', consumes lots of fuel.
And you've checked: No obvious intake air leaks, air regulator OK, electricals OK.
Suspects: TPS (I think it's only an on/off switch with no adjustment). Two injectors replaced recently.
See if anyone else can help diagnose the problem. BTW how old is this engine?
cheers,
JH