Hunting M40 vac leak.

Need technical Q/A then you're in the right place

Moderator: martauto

Grepot
E30 Zone Newbie
E30 Zone Newbie
Posts: 108
Joined: Thu Jul 30, 2020 9:31 am
Location: Suffolk

Post Wed Mar 23, 2022 6:15 pm

Hi zone.

Looking for some advice and motivation for hunting down a vac leak on my M40.

Somewhat recently replaced the head gasket and refreshed the injectors + intake gaskets. Had it all back together and it would either idle at 600ish nearly stalling or at 1200. Brake booster isn't working at all so I'm assuming its not a leak but rather an entire missed connection somewhere.

Are there any diagrams detailing all the vacuum hose connections for the M40? Realoem hasn't been too helpful. Also what would be the best way to hunt for leaks without investing in a smoke tester?

Thanks.