Help with my 84 hot air GN

[standupjskiguy]

When you adjust the idle adjustment screw

It's proper name is minimum air adjustment screw according to turbo tweak.
You are supposed to adjust it for IAC counts of 10-40. If after doing this, if the idle is high, I believe it indicates a vacuum leak.
With the proper IAC count, the ECM is suppose to control the idle at the proper level.

 

[standupjskiguy]

I've been researching adding an 86-87 ECM to my 85 hot air car. I read that the 85 does not have a MAT, (air temperature) sensor.
If you install an 86-87 ecm, you will get a SES light. It's a fair bit of work to install the MAT but I think you have to do it and
it also says you need the 86-87 MAF. I'd say you have to get these resolved.

Read about it here:
http://www.gnttype.org/techarea/ecmsensors/8487ecm.html