BMW 325i Mystery Wire - Car wont start

Post Sun Nov 25, 2012 7:10 pm

Hi All,

Having a bit of a problem (self inflicted).
Just completed adjusting the valves on my 325i; while putting the valve cover back on however I accidently pulled a wire out of it's harness - now I'm not sure where it goes.
Main symptom is that the car wont start, the starter motor turns, I can see all the belts moving but the car wont fire (doesn't even sound like it's trying really).
The wire itself seems to be coming from a loom which heads down the side of the engine back towards the firewall.

Hoping someone might be able to recognise the wire and tell me where it goes - really stupid I know but can't find where it came from for the life of me!

Photos of wire:

Would really appreciate any ideas/suggestions!

Thanks
Ben

Post Sun Nov 25, 2012 7:14 pm

Hi Ben,

Welcome to the Zone!

It looks like an aftermarket 'Lucar' connector, female socket side, so you need to look for a corresponding male plug that fits into it, which may also be blue in colour, though not necessarily.

Seeing as you've spun the engine over, it may have got trapped in the fanbelt and dislodged or even yanked off, so you'll need to take a good look at the area around the front pulleys.

Post Sun Nov 25, 2012 11:18 pm

Thanks for the replies - will have a look tomorrow after work

Post Mon Nov 26, 2012 10:02 am

Hi there, what would be good to know is why the engine is not firing. Is it lack of fuel or spark?

I was going to say the crank sensor but then realised the engine is pre facelift so this will be on the gearbox bell housing.

I know the OEM wiring for the coil runs along the bulkhead, but could this be a homebrew security measure/bodge, that connects to the coil somewhere?

Post Mon Nov 26, 2012 10:38 am

Hi all,
Seems to spark, starter motor turns, crank sensor is in place.

Plenty of fuel too. I need to get it up on axle stands and have a good look. Will let you know when I get back from work.

Post Mon Nov 26, 2012 4:41 pm

As above on diable's post, checked all the fuses? There are about 3 that are linked to the fuel system (according to one fuse box map I saw, the zone one only mentions fuse 11) and it is a simple and easy thing to check.

E: http://www.r3vlimited.com/board/showthread.php?t=60297
There are a few that are linked to 'Fuel delivery' so I'd make sure to check those (although I'd check all fuses anyway).

Post Mon Nov 26, 2012 4:47 pm

Do a PROPER spark check by putting an HT lead on a known good spark plug and turning the engine over. Can't advise any further until you report back.

The full checklist is here:

http://www.e30zone.net/e30zonewiki/inde ... oubleshoot

Post Mon Nov 26, 2012 10:50 pm

The only fuse in the fuse box that affects the fuel delivery is fuse 11, which should be 7.5A.
An E30 with a rear mounted battery also has an inline fuse in the smaller wire that leaves the battery positive terminal, which, if blown, will cut power to the engine loom and the fuel pump.
Don't start messing with random irrelevant parts - you stand a good chance of introducing more faults that you didn't have before. The key to fault finding is logical testing, as in Grrrmachine's wiki link.