Hi guys, New guy here with a Rs13 200sx with Ca18det engine stage 2 tuned.

One morning when I went off to work, the car didn't want to start, Engine cranked but no buzzing from the fuel pump. Checked the fuel pump fuse but it was OK.
Then I realised that none of the 3 green relays (ignition, EGI and EGI pump) were closing. No sound from them what so ever, Late for work I left the car at home.
When I got home I continued my troubleshooting. I bridged pin 3 and 5 on the fuel pump relay and the fuel pump immediatly starts working. So no problem there,
But I have no spark so the car still doesn't want to start.

I've switched the relays around and tried again but no luck. Measured the voltage in EGI relay pin 3 and 5.
Pin 5 to ground: Battery voltage 12,8 volts
Pin 3 to ground: 7,4 volts.

This doesn't seem right to me. I have followed the black/white wire from pin 3 to the Ecu pin 109 which I read is the ECU Power supply. I cant understand why I have 7 volts there when the EGI relay is open. The voltage must come from the ECU?

Checked for faulty codes and it shows nr 43 and nr 21

21 - Ignition signal missing in primary coil Wiring fault etc., sensor, ECU No or difficult start, bad idle, misfires

43 - Throttle position sensor circuit Wiring fault etc., sensor, ECU lack of power, low economy, stalling

I have measured the tps and it seems ok.

Any idea what next and how to solve it? I am completely clueless.

This is odd behaviour. To me that indicates a bad ground. Find every ground you can (check the FSM, they're in there) and remove them all and clean them. I would also suggest putting some anti-sieze on them to prevent them from corroding again. Let us know what you get after that.

Thanks for your input. Yeah I will check the grounds.

What do you mean by FSM?

Factory Service Manual. There's a link to download the copy in the FAQ.