M52 Wiring problems :/

Moderator: martauto

User avatar
CarlNewman
E30 Zone Newbie
E30 Zone Newbie
Posts: 67
Joined: Wed Oct 03, 2012 11:00 pm

Post Mon Sep 01, 2014 11:51 pm

Done the m52 2.8 conversion recently. All has gone well mechanically but electrically not so good.

When first attempting to start it was cranking perfectly. So went and wired up the EWS still cranked but no spark. Checked over all the wires then it was time for bed. Next day went to crank it but now there's nothing? Turn the key and the starter motor doesn't even spin. If I turn they key on and off fast I occasionally hear a Knock from the starter?


Any ideas?
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49359
Joined: Mon Jan 10, 2005 11:00 pm

Post Tue Sep 02, 2014 10:50 am

Unless you've connected up the starter wiring to the relay in the EWS module (as it was in the original application), then your cranking circuit should be exactly as it was with the original engine.
Not a complicated circuit, but the problem could be anywhere along it! Find the black/yellow wire somewhere along its length (plug half way down the steering column, plug above the glovebox, the C101, or even at the starter motor and apply 12 volts directly to it with a piece of wire from the battery.
User avatar
CarlNewman
E30 Zone Newbie
E30 Zone Newbie
Posts: 67
Joined: Wed Oct 03, 2012 11:00 pm

Post Tue Sep 02, 2014 1:18 pm

I've just tried connecting the yellow/black wire to a batter and when I do so the starter motor is throwing the wheel foward but I can not get the starter to spin?
User avatar
CarlNewman
E30 Zone Newbie
E30 Zone Newbie
Posts: 67
Joined: Wed Oct 03, 2012 11:00 pm

Post Tue Sep 02, 2014 2:20 pm

Finally got it to turn over, honk it might if been stuck! Now my only problem is getting the thing fired up. I have no spark /:
User avatar
CarlNewman
E30 Zone Newbie
E30 Zone Newbie
Posts: 67
Joined: Wed Oct 03, 2012 11:00 pm

Post Tue Sep 02, 2014 3:43 pm

I now have spark, but no fuel. I maned to get it fired up with easy start. Any suggestions?
User avatar
Supafly
E30 Zone Regular
E30 Zone Regular
Posts: 559
Joined: Wed Feb 22, 2006 11:00 pm

Post Tue Sep 02, 2014 4:12 pm

Check that your fuel supply pipe is the right way round.
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49359
Joined: Mon Jan 10, 2005 11:00 pm

Post Tue Sep 02, 2014 7:41 pm

Supafly wrote:Check that your fuel supply pipe is the right way round.
Supply pipe (the one with the filter) goes straight to the injector fuel rail. Return pipe goes to the pressure regulator.