m52 swap and MS3x questions-Crank/Cam sensors

[haaken675]

Hey Guys,

I am started to get myself a little confused regarding the crank and cam sensors unfortunately. I am in the process of finally wiring up my ms3x to my m52 wire harness. I read (and of course I can't find out where now) that the m52 cam sensor is neither hall nor VR, and that I would need an m50 sensor instead, I already ordered and installed that new m50 sensor (after already installing a brand new m52 one...).

I am searching for install instructions for which wire goes where, and came across people saying that the m52 crank sensor is the issue.

Can someone that has done this point me in the right direction so I stop spending money on parts I don't need? Which crank/cam sensors should I be using? Also, if anyone could point me in the direction of which wire does what on the sensor end that would be amazing as well.

[haaken675]

Ok, so I think I figured out the crank sensor. From what I have been reading, the consensus is that the m52 crank sensor is a hall effect sensor. Wires should be black: sensor output to ecu, yellow: 5v input from ecu, and brown/black: ground.

I am running an m50 cam position sensor now, which I understand is also a hall effect sensor. My issue is that all of the wire diagrams I am looking at don't seem to really match up, and that is on top of the fact that I am using an obd2 wire harness and the obd1 cam sensor...Can someone confirm for me which wire does what for the cam side?

Thanks

[pazi88]

As far as I know, pin3 is ground, pin2 is signal for ecu and pin 1 is +12v from dme relay. But couldn't find 100% confirmation about that so I used m52tu intake cam sensor which is hall sensor also and direct replacement to single vanos head. Only two tabs needed to be removed from connector to fit it single vanos wiring harness.

[haaken675]

Thanks for that! That looks consistent with what I am seeing now. I hadn't realized that the pins were labeled since all of the diagrams I was looking at showed different orders despite being numbered.

[haaken675]

Aright, so another twist. I got the entire harness all wired up, and when I went to plug everything in yesterday I found out that my OBD2 harness won't plug into my OBD2 crank sensor? The harness side is a female connector, and the sensor appears to have a female end...AM I missing something here?

[haaken675]

same goes for my OBD1 cam sensor...Now I realized that the OBD1 cam sensor has a female end and my harness also has a female end...WTF am I missing here...Nothing I read about online mentioned that the ends wouldn't mate up, or else I would have just found a way to machine adapters for universal sensor.

[ZekeTheSneak]

Ok couple of questions. Which crank sensor are you using? Front timing cover sensor or the one on the back of the block? There is a recall on us crankps and they sell a wiring harness kit with it. Look up crankposition sensor recall m52. From the factory it had the sensor mounted to the timing cover. The recall puts it towards the bell housing.

Obd1 and OBD2 cam sensors are 3 wire but the plugs are inverted male and female from obd1 to obd2. Pazi88 uses the euro front crank position sensor I believe. Markert sells them. Pazi88 also uses the cam sensor from I think the m54... But I'm not positive. That might help clear up some confusion.

[pazi88]

Yes m54/m52tu cam sensor which is hall type. It plugs directly in after two tabs are removed. And stock front mounted cps. The rear mounted works fine also but it uses 12v instead of 5v as the front mounted onem but that extra wiring for rear mounted cps, takes the 12v to sensor from vanos solenoid.

[haaken675]

Well, I got fed up of going back and forth, ordering parts that just don't work, and wasting time. I purchased DIY Autotune's hall effect sensors, modified the mounting tab ever so slightly, and the car runs and start perfectly now (as perfectly as an untuned car can). Zero sync loss at all. I really wish I had just done this from the start. I completely replaced the shielded wire on both cam and crank sensors as the 20+ year old cable was brittle as can be. Honestly, in my opinion, this is the best option as it is the cheapest one and has yielded great results. The car fired up the first time quicker and with less cranks then it did with a stock m20...