BMW E36 OBDII Crank Sensor

Discuss which Sensors work best with these ECUs and share how you are using inputs and outputs
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science
Posts: 13
Joined: Sun Oct 16, 2011 10:48 am

BMW E36 OBDII Crank Sensor

Post by science »

Not sure if anyone has any experience with setting up the OBDII crank sensor (hall effect from what I've read) with the DTA. I am currently using the OBDI cam sensor which is also hall effect.

I've had the car idling, however it idles rough, and A/F will jump around from 10 to 14-15ish even after adjusting the startup and main fuel maps. The crank oscilloscope seems to show the teeth properly, and the cam sensor also seems to be working even though there seem to be a significant number of cam errors detected. Could this be causing the rough idle, even though it says sequential is active? I am using shielded twisted pair for the cam sensor, and the shield has been grounded.

I am currently running sequential injection and spark. I was just wondering if this is most likely related to noise, if I need to switch to the OBDI crank sensor, or I need to better shield my cam sensor?

Also I am currently not using idle control.

Thanks
VR6Turbo
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ECU Model: S80 Pro
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Re: BMW E36 OBDII Crank Sensor

Post by VR6Turbo »

What engine is it? How many teeth does the cam wheel have on it?

Is the cam sensor a hall or magnetic and is it connected to the right ECU pin?
science
Posts: 13
Joined: Sun Oct 16, 2011 10:48 am

Re: BMW E36 OBDII Crank Sensor

Post by science »

It is a M52B25 from a 99 323is with the following:

.140" MLS
ARP 2000's
Precision Turbo 6262

The cam sensor wheel has 1 "tooth", it looks like a disk with the top milled flat.
The sensor is Hall and is currently connected to the Hall sensor pin on the DTA.
stevieturbo
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Re: BMW E36 OBDII Crank Sensor

Post by stevieturbo »

No such thing as an OBD sensor. OBD + On Board Diagnostics, so has nothing to do with sensors.

JonK should be along soon, he runs a BMW engine and can likely help. But if you are getting cam or crank errors, then that is a problem for sure.

Does displayed or logged rpm seem sensible, or erratic ?

And you say you used twisted pair ? Hall sensors are almost always 3 wire. power ( 5-12v ) ground and signal. They dont require the screen or twisting, but it certainly wont do any harm.
But they are 3 wires.

Magnetic sensors are usually always 2 wire, and should be twisted screened. They give two very different signals.

Which have you got ?
Jon K
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Re: BMW E36 OBDII Crank Sensor

Post by Jon K »

Hey sorry for delay - work has been busy!

The M52 uses a 60-2 wheel in the block with a hall sensor and a weirdo proximity sensor in the cam position I "believe". The hall sensor will want 12v on the crankshaft. The trigger angle should be 320 or 324 degrees or so.
1992 700RWHP Pump Gas BMW
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science
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Re: BMW E36 OBDII Crank Sensor

Post by science »

Thanks, Yes they are both hall effect, 3 wire sensors. The car seems to run fine, now I just wanted to verify that the bmw hall effect crank sensor, located in block, did in fact work with the DTA. I was told some people had issues with this sensor and to instead switch to the older front mounted sensor.

Displayed RPM seems to be sensible.
Jon K
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Re: BMW E36 OBDII Crank Sensor

Post by Jon K »

Nah I think people try it and get frustrated and give up on it. The issue is, of course, that you can't see the trigger wheel since its in the block so people had a hard time setting the crank angles up. The stock sensor works great. Oh, I think BMW at some point had it wired to 5v power and it didn't work reliably that way. There was a tech update to modify the harness for 12v.
1992 700RWHP Pump Gas BMW
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science
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Re: BMW E36 OBDII Crank Sensor

Post by science »

Ok Thanks, well I ended up swapping my vibration damper so that I can run the older VR style sensor anyway. I'm tempted to run the Hall effect sensor though, seeing as how you say it works. However, I was warned that if I continued to run it the engine could lose timing and under boost that would be catastrophic.

So I'm a bit confused as to which path is the best.
stevieturbo
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Re: BMW E36 OBDII Crank Sensor

Post by stevieturbo »

If the VR sensor works....why change ?
Jon K
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Re: BMW E36 OBDII Crank Sensor

Post by Jon K »

Stock is hall on this engine Stevie. He's going to retrofit an OBD1 VR sensor to the front. It'll work, but the stock sensor on his car is a hall sensor mounted in the engine block.
1992 700RWHP Pump Gas BMW
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