It looks as though I made a mistake over the last few days! Can you help please.

The recently purchased 1984 760GLE (185,000km +) has just had its fragmented engine wiring harness replaced and since it still doesn't run smoothly enough, neither at idle nor at speed, I decided it was time to change the spark plugs, ignition leads, adjust the valve tappet clearances and clean the throttle body.
It has no oxygen sensor system or frequency valve fitted.

I was soon staggered by the dirt in the inlet manifold and decided to pull it out and give it a proper cleaning. I found two unplugged bolt holes on either side of the manifold before the throttle body leaking unfiltered air into the system. These had however over time become blocked with dirt and grime. I blocked off the holes, cleaned all the fuel injectors' exterior surfaces using petrol and a cleaning pad, cleaned the inlet manifold passages (which were badly fouled) and the throttle body. I made sure all the air passages were clean. The old spark plugs were marked Volvo and may have been original, they looked so old.

I removed the start injector and cleaned it and the air control valve.
I removed all three idle adjustment screws after the throttle body and thoroughly cleaned them as they were badly fouled.

As I removed the fuel control assembly the two vacuum tubes that enter it at the bottom of the throttle area dropped off from their locations at the back/underside of the inlet manifold. I think one came from a PCV? valve into the top of the engine block below the inlet manifold (the small plastic fitting has provision for two tubes to enter it). The other came I think from a vacuum tube system at the back of the engine near the distributor.

I reassembled everything as I think it should be and made sure all electrical connections were clean and firm. I unscrewed each of the idle adjustment screws about three full turns as a starting point and tried to start it up but can only run the engine above 2000rpm. Anything below that and it will stall. If I let it drop below 2000rpm I can pump the throttle and it will recover and rev freely back up to 3000rpm, but no way will it idle.

I have checked the FAQ for help. I tried various adjustments for the idle screws. I don't think there are any vacuum leaks as I used hose clamps to tighten any loose tube fittings. No way will this unit idle!

Does anyone have a schematic or exploded view of the vacuum system that they can send me? That may eliminate the possibility of its incorrect reassembly.

Can you advise how I can test the air control valve. Could my cleaning of it have caused it to now stick and would this stop it from idling?

Can the the V6 Gurus please come to the aid of one who would like to get a better understanding of this beast.
Many thanks in advance and Happy New Year from Sydney!