There are series of sensors which receives power from pin 2A besides the AFM. So, unplug the TPS and test pin 2A again w/key to on. If that doesn't change things for the better then move on to the Boost Sensor and unplug that as well and test pin 2A. If that doesn't change things correctly then proceed to the Variable Resistor and finally to the Atmospheric Pressure Sensor. Chances are one of these is pulling down the supposed 5 volt reading pin 2A should have. If none of these things changes Pin 2A for the better then perhaps there is something wrong w/the ECU.

And pin 3J is powered by the Room fuse (7.5 amps) as you somewhat mentioned this so check that particular fuse.

 

OK So I was following that pin 2A In the diagrams and I noticed it connected to the TPS, which I got bad voltage readings all around so I unplugged it and now it doesn't turn over at all! Theres an electrical shorting kind of noise and the tachometer just seems to rise as long as I hold the key to start which I didn't do for very long. I tried unplugging the trailing coil from power and nothing changed except for no tachometer reading.
PROGRESS! I think. Voltage on either 2A or 2E didn't change.
I'll continue after lunch.

 

What bad readings did you get at the TPS which only has three wires? The G/R is rather irrelevant unless the engine is completely warmed up so that leaves only two other wires which are the ground wire and the wire shared by the AFM and other sensors listed in the previous post. Plus disconnecting the TPS has nothing to do w/the engine turning over at all so this is rather perplexing.

 

The ones at the ecu. It worked in my head anyway. So with each individual thing unplugged on its own the only thing that changes vref voltage is the afm which bumps it up to 2vdc. I unplugged tps, afm, aps, variable resisitor, and boost sensor individually and then all together. I only tried starting it with them all unplugged so maybe ill plug each one in and when it stops turning over I've found something? My battery is getting low from how much I have been turning the starter.

Update:
No change. I can't get the tach back up, I can't get the short noise. Maybe my battery went dead? But when I unplugged the tps it could turn the motor over again?
The only way to make vref change is to plug in and unplug the afm. Unplugged at 2vdc plugged in at around 1.85vdc. I could try my other afm to see if that helps?
This is also between two ECU's. I plugged in my spare to see if it would change. No change in AFM volts or VREF volts.
Oh I forgot to check the 7.5amp fuse. I'll be back with results of that.

 

When you say bumped it up to 2 volts are you suggesting that the voltage was lower than 2 volts? Do you believe you can depin or remove the wire from pin 2A? If you can then take a voltage reading from the ECU directly rather than the back of the plug. And this makes me want to ask you, are you taking these readings w/the plug connected to the ECU or unplugged? Should be plugged in. And stop trying to start the car for it's not going to start w/some of the readings you have thus it is useless and draining your battery in the process.

 

7.5amp fuse was really messed up. Blown, but then made contact again. Eek.
Going to go buy a new one.
I don't know about depinning the wire. Could I just remove plug 2, turn the key to run to power on the ECU then test pin 2A? I've been testing it with the ECU plugged in.

 

You could try that.

 

Tried it. 5v with the plug 2 unplugged. Wiring is bad? Different AFM didn't change things much.

 

It appears the wiring to the sensors is bad and shorting out. So, you need to ohm test the wiring to find the short. The easiest segment of wiring to check would be the wire in pin 2A while unplugged from the ECU and the same wire at the ATP sensor as they are so close to each other. If you're not familiar w/the ohm test then just place one meter lead to the unplugged wire in pin 2A and the other meter lead to the Br/White wire at the ATP sensor also unplugged and w/the meter set to ohms it should read a very low number. And again, no key necessary for this type of test.

 

91 ohms on the variable resistor.
I get 125 ohms from the far right prong of the afm but theres a pin I get 1 ohms from and 2 pins I get 4 ohms from.
1 ohms on tps
1 ohms on boost sensor with another pin getting 4 ohms.
I cant see anything wrong with the wiring on the variable resistor.

To do this test I put a wire in the plug on 2A and ran it to the engine bay and unplugged the sensors and touched the plug inlets.

 

The Br/W wire from the ECU only runs to one pin at each of the five sensors thus that's the only pin/wire to be checked. And don't forget the ATP. 1 ohm is okay but the Variable Resistor and AFM are off the charts especially if you ohmed out the correct wire. You can always switch the meter to continuity to prove that you are testing the correct wire.

 

When i ohmed outwhat I thought was the variable resistor and saw 90ohms, I started following the wires looking for bad ones, and saw something else. I tried unplugging it and found a pin that ohmed to 1. I was looking at the wrong thing! I unplugged the real variable resistor and it ran! Woooooooooo! My lord being without my car for a week was terrible!

Dude, I owe you a beer or something. Thank you.

So I went and got my spare and put it in. Idles better, runs better, my idiot lights come on with the key in run, the belts buzzer doesnt sound like its dieing, everything seems better. Except I have a loss of engine power. Completely unrelated I assume. I don't know, I'll figure it out

 

Good to hear.