Does anyone know where the write up for this is?? I searched but couldn't find it.

Peace,
jonny

 

OK guys,

Forget it - I found it. For anyone looking for it

Left: GROUND White/Black
Diagnostic Connector Purple
Input from Main ECU Red/Green
12v Power fm EFI Relay Black/Red
Right: Power TO Fuel Pump GREEN

First, I would get out my voltage tester, and confirm with ignition switch on : 12 volts on the Black Red Wire, 8-12 volts on the GREEN wire. If this checks:

1. DISCONNECT THE BATTERY!!! Can't be too careful with that main Engine ECU
2. Leave about 2 " of wire on the ECU connector in case you want to reverse the process later
3. Cut BOTH the BLACK/RED Wire (main 12V power from the EFI relay), AND the GREEN wire (power TO the fuel pump)
4. Join the two wires together you've just cut (NO!! NOT the short ones still on the connector, but the other two ends!) DON'T use the hokey household romex twist connectors as shown in the pics on the SUPRA site. Do it right, with a good solder connection and heat-shrink wrap over. After all if this connection fails, you are definitely gonna be WALKING! (not an easy roadside fix)
5. Tape over the two separate ends of the 2 inch wires left on the connector (shouldn't be necessary, but just to be safe.

That's it! You've successfully eliminated the Fuel Pump ECU!
2. Cut BOTH

Peace,
Jonny

 

nice job. good write up, of course i'll double check everything first. but nonetheless its a great start. make sure you solder your connections

 

What does bypassing this ecu do?

 

You can read about it here for the Supra

http://www.mkiv.com/techarticles/12v_mod/12v_mod.htm

I am doing it because I think mine is bad - I don't remember what, if any, the benefits are.

Hope this helps,

Peace,
Jonny

 

A few of the benefits are discussed here:

https://www.clublexus.com/forums/sc-1st-gen-1992-2000/27948-anyone-know-how-to-replace-fuel-pump-ecu.html

Oh, and I didn't solder my connections. It's been almost 3 years and I have not walked once.