rb20det wiring problem

[DriftnR31]

I have an rb20det silver top which i am putting into my r31

the engine has been installed and i am currently trying to wir up the ecu.

I have sorted out a relay for the fuel pump and have power to the ecu as the led comes on.

what else do i need to wire up to get it to start?

any advice appreciated

[BH_SLO32]

Have you sorted out the wiring or do you still need help? I have an R32 and have identified all the wires in the plugs that attach to the body loom (4 off). Is it an Australian delivered R31 skyline?

The ecu gets its power (pin 58 and 59) from the ECCS relay. This relay receives its power from the gray plug in engine bay near the power steering reservoir (white wire with black stripe). This plug also supplies power to the ignition coil relay via the white wire with purple stripe.

The black wire with red stripe provides an ignition switch IGNITION signal to the ecu (pin 45) and provides power to the ACC valve. The remaining wires in this plug are for the neutral switch, power steering switch and AC (AC cut signal).

The plugs near the ecu itself (3 off) have several important wires namely:

1. ECU ground

2. Air regulator power supply

3. Heater (O2 sensor) power

4. Ignition switch START signal (pin 43)

5. Fuel pump relay (pin 18)

Other less important wires include speed signal, tacho output, check lamp, water temp gauge and AC switch.

Give us a jingle if you need further assistance. I've put an R32 RB20DET into an R31 passage back in 2000 and wired it up successfully.

Cheers

[DriftnR31]

thanks for the reply.

yes its an aussie delivered r31.

ive got the two constant power wires from the grey plug near the washer bottle connected and am getting the ign to turn on the ecu via the body plug near the ecu in the r31.

I have been told that you do not have to ground the ecu as it gets a ground from somwhere else and as long as you ground the motor it is ok. (doesn't sound right tho.)

i have also got the ignition start signal connected via the body plug near the ecu.

now the problem is whilst i was working on it two wires touched and shorted, melting a pin in the ecu and also melting the ecu plug.

So i cracked open the ecu and have removed the melted pin and hard wired a wire into its location and have drilled a hole in the ecu's case so the wire can poke out. I thought this would be ok but after wiring everything up and checking everything many times im still not getting spark, so i think i have damaged the ecu. (although the red LED still turns on)

so now im looking for another loom and ecu

[BH_SLO32]

Sounds like you have the main power feeds sorted. I would also suggest you wire in a power feed for the air regulator (Black with yellow stripe in 16 pin plug). The R32 provides power from the same source used for the fuel pump. It draws its power downstream of the fuel pump relay (ie it only sees power when the ecu earths the fuel pump relay).

The power supply to the O2 sensor heater is the light brown wire in the small 12 pin plug. It receives power when the ignition switch is turned on.

You are right about the earth, the ecu ground (pin 50 and pin 60) and the ecu injector grounds (pins 107, 108 and 116) earth via the 2 ring connectors secured to the intake manifold below the fuel regulator. Provided the engine is earthed this will be fine.

The earth wire belonging to one of the loom plugs inside the car that I mentioned in my last post, I believe joins to the consult connector. The reason I say this is the other 4 consult wires are also included in this plug. Incidentally there is continuity between the two, although being an earth this doesn't mean much.

With respect to the ecu short, I would suggest there is a strong possibility the ecu is damaged. The ecu doesn't like big currents hence the use of relays and power transisters etc.

My brother-in-law has a loom for a manual RB20DET which I currently have lying on my chair. I was going to buy it off him as I would like to use its body plugs to adapt an RB25DET loom for my R32 (fitting a S2 RB25DET in the coming weeks) but I can use the loom from my motor if I have to.

If you are unable to locate a loom let me know because I know he wants to sell his.

Hope this helps.