Electrical issue c33 Laurel rb25det

[Adrianrb]

So I have a c33 laurel swapped stock rb25det built myself and been running for a year with no issues, Couple months ago my car started to just shut off while driving no pattern emerged as to when or why, would just be completely random. Sometimes would go days without doing it sometimes 3/4 times a day. All I would have to do is just turn the key off and back on and she would fire straight back up. 

Then progressively got worse and I’d have to turn they key a couple of times. Then got to the point it wouldn’t fire, I assume electrical but Ive got no idea where to start looking. 

Basically when it happens I loose all dash lights after a split second, ecu still has power, radio still works, windows work, car turns over, fuel pump doesn’t prime.

so far I have tested every relay i could find in the car except fuel pump, pulled ever fuse, gone over all loom given it a shake to try source a possible loose connection or break in wire and found nothing

im thinking it could possible be my alarm but was installed by previous owner and wouldn’t know where to start. Completely stummed and would love to pick your guys brains to get her back up and running for summer 

cheers in advance for any help ??

[PLYNX]

Is it a series 1 motor ? Then its probably the air flow meter. The internal connector pins that are soldered together have come apart and need re-soldering. Run a search here on this forum i think there is a tutorial on it.

[WMDC35]

To test the AFM theory just unplug it and see how it starts 

[Adrianrb]

3 minutes ago, PLYNX said:

Is it a series 1 motor ? Then its probably the air flow meter. The internal connector pins that are soldered together have come apart and need re-soldering. Run a search here on this forum i think there is a tutorial on it.

She’s a series 2, I have been having problems with afm wiring definitely a crappy connection at the plug somewhere but tried having a wriggle around and doesn’t fix anything usually just goes into limp doesn’t shut car off when she plays up 

[Adrianrb]

Update... 

so ecu doesn’t have power when car dies but when power to ecu is unplugged in the engine bay the dash lights return 

I’m assuming fault with ecu have opened up and cannot see any visible issues, possibly short somewhere but stumped because will run for a few minutes then switch off and not run for a hour or two

with car running and I unplug afm car dies but will start and run in limp, return to normal once plugged in. I don’t see it being an issue with afm  

Edited October 2, 2019 by Adrianrb

[GTSBoy]

More than likely it's the ECCS relay, next to the ECU.