B18c OBD2a motor into OBD2b Chassis Problems

Alright, so i completed my swap earlier this year and have just been driving around with some minor problems but now they are starting to get to me.

First and foremost. the car runs, engine will start 100% of the time and will not die at all, although sometimes it gets close.

Background:
The motor is an obd2a B18c GSR
The chassis is an obd2b EM1
The wiring harness used came off of my b16a2 (obd2b)
The ECU is an obd2a b18c GSR and is being run using an obd2b to obd2a conversion harness
The secondary butterfly valve has not been wired up
No CEL at all

The problems:
1.) Tachometer does not work, i imagine because its an obd2a Dizzy and an obd2b plug but am not sure

2.) Really really rough idle, sometimes at idle the RPMs will bounce from 200 to about 1000 (this is a guess because as #1 says, the tach does not work) as if there is a vacuum leak somewhere, i cant find the leak at all. the nipple on the throttle body has been capped off. its worth mentioning that after about a minute or so the bouncing idle will become steady at.about 600 (slightly higher than normal).
other times, and i have only noticed this when the car is warm, the idle will stay at close to 2000-3000rpms steady (again, my best guess).

3.) How do i wire up my secondary butterfly valve?

1.) in a straight OBD2b car the tach is driven from the Ecu. In every other OBD the tach is driven by the dist tach output. The dark blue wire coming out of the dist goes to a dead pin on the OBD2b engine harness, you can take that wire and run it into the tach.

2.) tach doesnt go that lower than 500rpm. common causes for high or fluxuating idle are a vac leak or the throttle cable is too tight.

3.) since you are using a b16 engine harness this pin does not exist. Google the pin out for OBD2 P72 and locate the pin for IAB, run that wire to the butterfly solenoid. With ign on it should have 12v and the butterfly should move

thanks Muckman,

1.) I got the Tach running from your description so this is solved

2.) i loosened the throttle cable and it fixed the problem for a little bit but now it is back again, the revs when in neutral are at 2k. i did notice that my cruise control vacuum line is not plugged in, but i have no idea where it goes. so there may be a vacuum nipple that is uncapped somewhere. does anyone know where it goes on a obd2a b18c?

3.) i wired up the secondary butterfly using the pinout diagram for an obd2a ECU.

2.) thoroughly inspect the intake manifold, under it too for any open ports that may cause a vac leak. Trace all vac hoses to make sure they are plugged or plug into something. Check for tears in the hoses, especially around the clamps. Also double check the throttle body again, turn the throttle pulley closed with your hand and see if that makes a difference. Also adjust the idle set screw.