So I have a 96 EX now too, that I daily drive. (The 97 EX is now just a race car, and being rebuilt). I picked this car up for $900 with a "blown motor" that was really just a head gasket. Either way ever since I had the car it has problems with being sluggish at times and the idle dropping really low. Since its OBD2 I bought a bluetooth OBD2 reader and connected it to my phone with a little app called Torque.
When the car acts up I noticed that the timing degrees just drop to nothing for no reason. I cant seem to find any corresponding sensor input that causes the timing to fluctuate so much. It will just be running fine and then all the sudden it goes from idling at 6-9 deg of timing and it will start dropping rapidly until it hits -10/-12 (usually takes a few seconds for it to drop down this low) and then ofc the car wants to just die. then it will randomly go back up or if I flick the gas once or twice the timing will go back to normal.
Also sometimes while I am driving this happens, and I will see the timing go from 17-27deg all the way to 5-11 deg and then ofc it accelerates like trash. I noticed it happens more when its muggy out, but thats about it.
Map voltage is right, IACV is fine (replaced it already), IAT and ECT are also fine and within spec (also none of these things change when the idle drops).
Car is a stock 96 EX Couple with the original D16Y8 with the only known mod being a short ram (although sometimes i wonder if it has some kind of cam in there).

I'm thinking that I should try to swap the ECU but unfortunately since the car is auto I have to find another Auto EX ECU to swap it out and see. What do you guys think?

 

The ECU automatically adjusts the ignition timing based on engine load and rpms.

Any CEL codes?

Have you tried bleeding the cooling system and adjusting the idle speed as per instructions in service manual? See FAQs sticky.

 

sometimes it throws a CEL for the knock sensor, because the wiring i believe is a bit faulty. But when I check the readings during the time the timing goes down it doesnt show any missfire or anything like that. And I have adjusted the idle speed a few times. When its running right it idles perfectly fine. But I can just be driving and then all the sudden ill see the timing get retarded by 10-15 degrees.