M880 suddenly no spark

[mach1000]

Hi people,

I have a very strange problem, and gray hair are popping out of my head..

I have a engine which has been running perfectly, until the oilpump put an end to that. The engine builder then rebuild it to the exact same specs, and mounted a dry sump system on it. He then fitted another crank wheel and sensor, still running 60-2 like the original one.

The sensor is still a magnetic sensor, with a falling edge, and the scope looks fine when i crank the engine. I thougt the only change would be the CRIP, but nooo. I get an error on the REF noise Ar, and an error on the sync. The engine is only running on crank sensor, and was running perfect with the old sensor/engine. I assume that even though the crip is off, it will still fire, just at a wrong cycle?

I get no consistent spark on cranking, and it seams like the fuel during cranking is almost nothing. The rpm signal shows approx 180 rpm during cranking, but occasionally it goes 0 and comes back again. The only change in wiring loom, is the connector for the sensor. When i test the output all coils and injectors are firing perfectly.

If you like I can put a screenshot of my settings to you, unfortunately I didnt save any captures.

Any bright idea what to try, I get absolutely no misfiring or anything.

Best regards

[BMWTuner]

yes.. even with CRIP out, it´s should fire.. just in wrong timming (usually, i use strobe light to get proper CRIP).

I think it´s not comming up in sync due lack of crank speed.. charge more the battery.. or, do a specific test.. remove the spark plugs and see if the speed of cranking increases...

in my opinion, you should forget the fuel at this moment.

When i´m testing the ignition output, first, i remove the fuel pump fuse and work without spark plugs also (it´s help also to don´t flood the chambers with fuel without fire.. with fuel inside of cylinders, you decrease even more the crank speed.. and more far away from sync you are..).

After i got correct CRIP and strong spark comming up.. i put plugs and fuse back..

Ah.. check the crank sensor gap to trigger wheel.. big gap, decrease the voltage and increase the need of high crank speed to get proper signal..

[mach1000]

Thank you for your reply BMWTuner!

I have been cranking with plugs out off the engine, and the strange thing is that it would spark once while cranking then it would stop, and totally dead. Could there be something with the tooth ratio or something, or is that of very little influence?

I have tried to upload a screenshot of my ref settings the way they are know, maybe you can see if something seems way off.

Thanks

[BMWTuner]

Hi friend!

Why you selected the mode "8"?
Did you run the engine before in this mode?

If you have 60-2 trigger wheel in the crankshaft, you will have two missing every 360 degree(1 turn of your crankshaft), and, you have full cycle at 720 degrees.. so...you have two missing twice per cycle.

Try in mode 7 and let se if it's keep sparking..


Regards,


Matheus

[mach1000]

The engine has been running with these settings before, but I will try and change the setting when possible, unfortunately I dont have the car in my workshop. But thank you for your replys, perfect with another set of eyes!

I will get back to you as soon as possible.

Thanks, and a nice weekend to you!