This isn't my MS it's a mates and I'm trying to figure out why occasionally it just plain fails to work.

It's fitted in parallel to a 92, It's normally situated next to the OEM ECU in the footwell, but after having to be towed home one time it's been laid on the carpet horizontally.

After a week or so of zero issues he put it back to it's normal location, next morning, his car wouldn't start, the ECU had no power, (no LED's lit up). He 'tapped' the top of the case and it burst into life and was flawless.

So now if the ECU is back in the footwell in a near vertical position 90% of the time it won't work at key on, but a light tap on the case and it'll burst into life. If it's laid horizontally in the footwell it works every single time.

I've had the MS apart and can't find anything obvious wrong, cold joints etc. Wiring also seems to be good and solid.

Before I go and re-do every single connection on the board, anyone have any tips where to look where the fault may be? First port of call is the power side of things, but just incase are there any other specific spots I should look?

Cheers!

 

could be the db37 pigtail.

 

Voting for the Db-37 as well.

 

I'll pull it to bits this weekend then !