BMW E30 M20 Trigger setup

[Usav8or]

I'm trying to figure out how to configure the crank (engine speed) and cam (cylinder ID) sensors for my M20 setup. This model engine does not have variable timing and is normally configured with a distributor cap and rotor. We have deleted the distributor and replaced it with a cap and cam position sensor from Bimmerheads and installed individual coil packs for each cylinder. I can get the software to see trigger 1 when I tell it its a cam sensor, but not as crank sensor. I cannot get the software to see trigger 2 at all. Everything seems to be wired correctly. I'd like any advise anyone has to offer. It wont run without the triggers setup correctly. Thanks

[UVic Formula Racing]

Trigger offset of -97

I've done a turbo E30 M20 with that same cam sensor and a stock crank sensor.  These are the settings that currently run on it.  How does your setup differ?  Make sure the distance from the flying trigger tooth is not too far from the sensor

 

- Lewis

[Usav8or]

Thanks, that is extreamly helpful. I had the tooth count wrong on the crank settings. I had 58 (2 missing) and I was just going with the default arming threshold tables.

 I didn't go with a turbo setup, obviously, instead opting for the 2.9L Mahle motorsport stroker kit offered by Bimmerheads along with their stage-3 race head and a independant throttle-body setup from RHD. Just something different and fun. Yours looks like a serious speed machine.

I assume the "flying trigger tooth" you refer to is what replaced the distributor cap and bolts to where the rotor was. We're somewhat at a loss as the mounting orientation of that disc and where the tooth should be. 

Thanks again

[Adamw]

31 minutes ago, Usav8or said:

I assume the "flying trigger tooth" you refer to is what replaced the distributor cap and bolts to where the rotor was. We're somewhat at a loss as the mounting orientation of that disc and where the tooth should be. 

Orientation doesnt matter too much with a missing tooth crank wheel as long as it doesnt occur very close to the missing teeth on the crank.  What ECU do you have?  Does it have the built-in triggerscope?

[Usav8or]

The G4+ Thunder, and yes. Now that I have your trigger settings maybe I can get more use out of it.

 

[Adamw]

Do us a trigger scope, that will give us a pretty good idea if the cam sensor is ok:  https://1drv.ms/v/s!AiYbYlZQuRHPmieMTkwQDCXEb2LY

[Usav8or]

Thanks, I'll take a look. 

The trigger wheel we're wondering about is the one bolted to the camshaft that replaced the rotor and distributor and acts as the cylinder ID. Does that matter?

[Adamw]

36 minutes ago, Usav8or said:

Does that matter?

No, as I said before the only important thing is that it doesnt go past the cam sensor at exactly the same time as the missing teeth go past the crank sensor.  It is only used to tell the ECU which phase or rotation the crank is on.

[Usav8or]

Understood.

Thank you

 

 

[Usav8or]

 

22 hours ago, UVic Formula Motorsport said:

Trigger offset of -97

I've done a turbo E30 M20 with that same cam sensor and a stock crank sensor.  These are the settings that currently run on it.  How does your setup differ?  Make sure the distance from the flying trigger tooth is not too far from the sensor

- Lewis

I have everything programmed as you specified, but I'm still not able to get the ECU to see trigger #2 on the cam. If the sensor spacing from the trigger wheel was too far what would the indication be? What should the distance between the sensor and the trigger plate be, and what's the solution, none of it is adjustable? Thanks

[Adamw]

What sensor is fitted on the cam? Does the trigger scope show nothing at all on trigger 2?

[ClintBHP]

The kit you have normally uses the M50 sensor which is a 3 pin hall effect if I remember correctly ?

[Usav8or]

It’s a BMW M50 position sensor, and the trigger scope doesn’t show anything on trigger 2. Also, the only time it shows any RPM on trigger 1 is when I tell the software that it’s connected to a cam sensor and not a crank sensor. I’ve checked the wiring to each connector and the cable going to the crank has black, white, and shield. The cable going to the cam connector has red, white, and shield. I bought the wire looms A and B with the ECU and as I remember it those wires were pre-identified for those sensors. 

Jeff

[ClintBHP]

You have the cam sensor setup as VR and I am sure the M50 is HALL ?

[Adamw]

The M50 with Vanos has a hall sensor, the M50 without vanos uses a reluctor.

You can tell them apart easy.  The VR sensor has a male plug and a little nipple (iron pole poking out the end):

 

The hall sensor has a female plug and no titty:

So, which one have you got, and if its the hall, have you supplied power to it?

[Usav8or]

2 minutes ago, Adamw said:

The M50 with Vanos has a hall sensor, the M50 without vanos uses a reluctor.

You can tell them apart easy.  The VR sensor has a male plug and a little nipple (iron pole poking out the end):

 

The hall sensor has a female plug and no titty:

So, which one have you got, and if its the hall, have you supplied power to it?

The one I have has no "titty." I guess that settles that, I'll have to figure out which one I'm supposed to have. I wasn't aware there were different ones. Thank you very much for the info.

Jeff

[Usav8or]

That took care of that problem, thank you. 

Now to figure out the whole ignition/injector timing thing. Still can't get it to run.

 

[Adamw]

Injector timing isnt going to stop it running.  Ignition timing you can confirm with a timing light.  If your timing marks line up but it still doesnt show signs of life then try adding or subtracting 360 deg from your trigger offset.

[Usav8or]

Even though the ECU is acknowledging the sensors now, I'm not convinced the cam sensor is giving an acceptable signal so I'm going to replace it with a new one next week. The trigger-scope was not logical and the sensor I had available was old and brittle. 

In an earlier reply it was suggested to use a Trigger Offset of -97,  but honestly I don't fully understand how all that works, so we'll try again after we replace the sensors. The other odd thing is though we get a positive thest on the ignition coils when my mechanic tries to use his timing light it's not working. I don't know what's up with that, he says the gun was working the last time he used it. He's not a computer guy, he says he's "the wrench."  

[Adamw]

I wouldnt bother replacing parts yet.  What do you mean by the triggerscope was not logical?  Can you do one and attach it anyway?

Do you have RPM showing in the software when it is cranking?

[Usav8or]

Yes, it's showing RPM on trigger 1 when cranking. Trigger 1 on the crank looked fine, but there was barely a signal on the cam sensor (trigger 2). Once you pointed out the different M50 sensors (thanks BTW) the only one I could get my hands on yesterday was used one off of an early E36 and it was in rough shape.  I have to put the toy away for a few days anyway and the wiring guy is free from his race team schedule for a few day so he's going to wire in the new connectors. Once that's done I'll get a new trigger scope reading and check it all again with new sensors.  I've attached the logs that I have, but I don't know if there's anything to look at. Thanks

Trigger Scope Log 2019-03-6 10;36;10 am.llg Trigger Scope Log 2019-03-5 2;11;16 pm.llg Log 2019-02-26 2;31;36 pm.llg

[Richard Hill]

Try doing an ignition test with the timing light connected.  This will help verify that the timing light itself is working. 

[Simon]

A common trap is the need for external igniters on BMW coils. 

The lack of igniter can cause spark on test but then none during cranking as its not enough energy to fire when under compression..

[Usav8or]

We're using AcDelco C1512 coils. Does that still apply?

Thanks

 

[Simon]

I'm 99% sure they are a smart coil so should be fine.

The check is to measure the resistance between the signal pin and the 12V supply. If its low (around 1 ohm) then it needs an igniter. If its high (k-m ohms) then no igniter required.