Mystery connector

[jimbly2]

Hello - I recently got the local garage to replace a fuel line under the bonnet ( I was away otherwise I’d have done it!) and it’s has failed to start ever since. They claim there’s some sort of security isolator ( there isn’t ) but I’m a bit stumped - engine spins but no fire.
On closer inspection today I have a feeling they may have dislodged a plug/ sensor. I found this 2 pin plug disconnected - but I can’t see what it is or where it goes? Speed sensor? The car is a 1989 325i and it’s never not started before…
Any ideas on what this plug might be? Can’t see it on the wiring diagram

[Cloggy Saint]

Hard to tell from the picture but it's more than like to do with emissions. If your car is fitted with a cat' then this would plug in under the throttle body and go to a charcoal canister bolted to the inner strut tower. If the car has no cat' then it just dangles free. Probably nothing to do with your non starting issue.

[jimbly2]

Ah ok thanks - there goes that theory.. I don’t have a cat but maybe they’d started including the wiring by 1989

[jimbly2]

Turned out to be the fuel pump!