Frankenvic Vacuum line question

I have a 92 4.6 CV and had idle trouble so I replaced the Mass air sensor but was having some idle variation and began looking for vacuum leaks and came upon a 3 way joint connection in the pcv line that connects to the plastic fuel rail line and also to a line that goes (I think) to a vapor canister in the grill. This 3 way had a screw stuck in the side that someone had put in there to regulate how much vacuum these hoses would lose. As the rubber of the 3 way joint deteriorated the screw started flopping around causing my idle to vary. So I changed the 3 way joint with a generic hose joint but without the vacuum leak my car wont idle at all. I put a new pcv valve on...no help. So it runs without small hose to the the pcv valve connected. That\\'s where I am, don\\'t know where to go from there. Some Sherrif\\'s mechanic has rigged something and I am not sure how to fix?

That screw was a crude way to add an air leak, and the engine refusing to idle once the leak is sealed tells you it has been relying on extra air. On the 4.6, idle air comes past the throttle plate and through the idle air control valve on the throttle body. When that valve and the throttle bore get coated with carbon, the engine is starved for air at idle and stalls, and a deliberate leak like that screw hides the problem instead of fixing it.

What I would do:
1. Remove and clean the idle air control valve and clean the throttle body bore and plate with throttle body cleaner, engine off.
2. Put the PCV and vacuum lines back together sealed, with nothing left open.
3. Start it and let it idle with the accessories off for a few minutes so the computer can relearn idle.
4. If it still will not idle with everything sealed, check whether the throttle stop screw has been turned and pull the codes. A worn out idle air control valve can also be replaced.

Dana