Did you check all the fuses in both engine compartment and inside car properly (method: http://www.dsmtuners.com/forums/showthread.php?t=179914)?
Then check if ECU pin 103 (red/black wire) has backup power which must always be there (from inside 10A fuse #19 which also powers room lights).
Then check MPI relay operation and if it's getting power on the black/red wire from it's 20A engine fusebox fuse.
Then check for good grounds on ECU pins 101, 104, 106.

Did you check ECU for leaking capacitors?

ECU pinout: http://www.vfaq.com/mods/ecu-harness-1G.html

Check and make sure you didn't accidentally pull off or break the wires leading to the ECT (engine coolant temperature) sensor on the thermostate housing while fixing the heater hose.

I messed with the car today, and I get this weird clicking sound like a relay trying to connect. You can only hear it from the driver side floor, facing the kick panel, and laying underneath the car. You can't hear anything from standing over the engine.

I checked the ECU, and no leaky caps. The power for the AFC is connected to the the smaller harness off the ECU on a solid red wire. That wire is no longer receiving any voltage. The MPI relay is clicking while cranking the car.

After I stop cranking you hear the fuel pump stop, but you don't hear it "prime" when I place the car in the ignition position. This is when I hear that noise.

90awd4g63 said:

but you don't hear it "prime" when I place the car in the ignition position. This is when I hear that noise.

Click to expand...

The fuel pump only turns on when the car is cranking, it will not prime at the "on" position.

Nope

90awd4g63 said:

Nope

Click to expand...

What do you mean "nope"? I wasn't asking you if it does, I was telling you that is normal.

But it used to run in the on position for a quick minute.

90awd4g63 said:

But it used to run in the on position for a quick minute.

Click to expand...

I have had my 90' for over 13 years now and it never does, unless the previous owner did some re-wiring.

Go back to the basics, check for fuel, spark and compression.

Well, checked for spark, compression. It's fine. Any other thoughts or recommendations before I purchase an ECU?

Just another question involving this whole no starting thing.

Found the weird noise. It was from my EVC IV boost controller. When you turn the key, the solenoid for it, which is mounted in the engine compartment, makes that low toned clicking noise. Could this cause the car not to start?

I had a lower FMIC hose come completely loose and it still started. I just couldn't build boost.

The other thing is, which I totally forgot, is the case of the lights. I'd be driving in the morning and have lights on. They would flicker like I had a big system, which I don't. This is would happen with the headlights and parking lights, and just the parking lights on.

Also, sometimes when it was starting, the "idiot" lights would take a really long time to go off? Is this a tell tale sign the ECU going out? All this occurred in the week prior to the car just dieing on me.

Please help!!! I don't want to buy anything I don't need.

Come on guys, if the CEL doesn't come on when you turn the ignition on and go off 5 seconds later then the ECU isn't working and the car will never start. The SAFC not turning on is another indication that the MPI relay isn't providing power. That could be due to bad terminals at the battery, bad MPI fuse, bad MPI relay, or a bad ECU.

I'll save you a search.

The ECU has two different power inputs.

Backup power comes to ECU pin 103 from fuse 19 (room) by the drivers left foot. Backup power is used to retain the contents of RAM in the CPU, it's the same circuit that the power to maintain the radio setting comes from. You should always have 12v at ECU pin 103.

The MPI power comes from the 30A MPI fuse on the battery + terminal to pin 10 on the MPI relay. Inside the MPI relay it goes the contacts and through a diode to one side of the coil so you'll see 12v at pin 8 on the relay because that's the other end of the coil winding and runs to ECU pins 63 (Control) and 66 (Sense).

There is one other input to the ECU involved in powering up and that's the signal from the ignition switch RUN position (IG1) that goes to ECU pin 110. The ignition switch has it's own set of fuses. The ignition circuit provides power to the power transistor, coils, and fuel pump.

When the ECU sees +12v on pin 110 it pulls it's side of the MPI relay coil to ground (ECU pin 63) causing current to flow in the coil and close the contacts connecting MPI relay pin 10 with MPI relay pins 4 and 5. They feed power to ECU pins 102 and 107 as well as the MAF, CAS, BCS, ISC, Injectors, purge solenoid, fuel pressure solenoid, and EGR solenoids.

With the arrival of +12 to ECU pins 102 and 107 the main +5v regulator starts and logic resets the CPU. At that point the ECU should turn on the CEL for 5 seconds if everything is normal, set the boost gauge to read 0 and prepare for you to start the car.

You can check the MPI relay by grounding pin 8. If the contacts close and you see 12v on pins 4 and 5, it's good. If you don't have 12v at pin 10 on the relay all the time then the MPI fuse is blown or the wiring is bad. If you don't have 12v at relay pin 8 then the coil in the relay is bad.

If ECU pin 110 doesn't have 12v when the ignition switch is in RUN then there is a problem in the ignition circuit or the ECU is really fried.

If ECU pin 63 doesn't go from 12v to 0v (or within a half volt of 0) when 12v is applied by the ignition switch the ECU is bad.

So go check the for power at the MPI relay, try grounding MPI relay pin 8 and see if the power turns on. If it does it's likely tile to get your ECU fixed.

Steve

Steve - Are you getting horse yet? I've seen you explain this (1g ECU power-up sequence) so many times. How about just putting all this in a Tech Guide article for everyone (and maybe adding the 2g pins also?). And then we can just provide a link to it for people and you can have your voice (or fingers) back!