BWM K75 starting / running problem
 

Hello out there, I'm new to the forum and looking for some help.

I have just dropped a BMW K75 engine into a small car (can't ride at the moment, docs orders) I have done the mechanics, done the wiring yet it refuses to kick into life.

I have got spark, I have got fuel (new injectors) and everything powers up. Crank the engine over and you get some coughs and barks, but nothing to speak off. I am getting fuel thru the injectors. I have disconnected my fuel pump and opened the throttle bodies full, turned over and got flames back up the throttle body.

I don't have a clue at the moment as I have checked literally everything. Only thing I can possibly think off is coil wiring / spark plug leads on wrong.

As far as I am aware, #1 cylinder is at the front where timing cover is.

so i have got:-
#1 cylinder to first coil - black/blue wire.
#2 cylinder to second coil - black/red wire.
#3 cylinder to third coil - black/green wire.

Anyone have any ideas and help me out?

Hallsensor/wire?
I.e. is the timing off?

Since you have spark and fuel - it should jump to life... I have an Inter-lombardini 490 one cylinder which presents the same kind of behaviour. It is pull-started... guess who is brakeing a sweat and who is just laughing about it! My engine is getting choke by too much petrol and a faulty carburator - could your engine be getting too much petrol as an alternative cause next to a faulty timing ?

Hello albert,

Thanks for the reply.

I was thinking about the excessive fuel part, I have bypassed the fuel pump and pressurised the fuel rail, Opened the throttle bodies and there is no weeping from the injectors. I used my snap-on test probe and tested each injector if it opened and shut. all three were good.

You know that feeling that your missing something and it's staring you in ya face.

The hall sensors are working as all the coils are firing (tested with strobe light)

:funmeterno:

sounds more like you have timing out if she's firing thru the throttle bodies

I am happy to report I got the engine up and running. I think the fault lay with a faulty fuel pressure regulator. It was either stuck open and not letting fuel to build pressure up OR it was closed and letting tooo much pressure build up.

Any way, Here is a video of the engine running

100_4594.mp4 video by boothybunch - Photobucket