S52 clone crank sensor problem

[Retrostudio]

Hello guys,

I have built a S52 clone using M50 block, m54 crank and rods, S52 pistons and S52 cams. I dropped the engine into my E28 chassis and now i have problem with the engine not running right. I get the crankshaft and ICV fault. The dme is MS41 from a M52 and i already ordered the S52 dme. im using E36 harness which was made by redlinemotorsports to work with E28 chassis. I'm confused what sensor to order?? S52 sensor or M50 sensor or...takes awhile for the engine to fire up and the car not pilling as it should. I really appreciate any help.

[Northern]

If it's an M50 block, you won't have the boss on the block for the OBD2 crank sensor, so you'll need the Euro M52 sensor for the trigger wheel on the harmonic balancer, unless you have some sort of adapter.

I'm interested in how you have the crank sensor hooked up now and what sensor it is using?

[Retrostudio]

Thanks for the reply Northern. I'm using the sensor from Euro M52 alu block. Its hooked up with no adapter. I also tried the sensor from US M52 and engine wont start. So confused

[moatilliatta]

Are you using a M50 vanos or M50 non vanos crank wheel?

The adapter you maybe talking about is the retrofit for a hall sensor? I'm running A Genuine Euro M52 sensor with out the retrofit harness and working good for 2 years.

Do you have spark and injector power and pulsewidth?

[Retrostudio]

I'm using Euro M52 vanos crank wheel. And yes i have spark and injector power. Car runs but i'm not feeling any power. It was much faster when i had the M52b25 in there. I have cheap ebay headers, complete custom exhaust, stage 2 clutch kit and lsd diff.

[moatilliatta]

How did you break it in?
how are the compression numbers?
Check Cam timing?
What were BMW fault codes?
Brand of crank sensor?
Try another ICV?

[ForcedFirebird]

Might want to check your 5v ref output. I've had a few DME's get boned because the TPS wires get chaffed at the connector, short, and blow out the 5v. You'll get all kinds of weird codes for, ICV, crank/cam sensors etc - basically anything that needs voltage reference.

Have you tried a different DME?

[Retrostudio]

I drove it for 100 miles and dme was extremely hot to the point i couldnt touch it so i ordered a new dme. Compression numbers and cam timing are correct. The fault codes are :
carnkshaft sensor
idle speed Actuator : closing coil
idle speed Actuator : opening coil
I cleaned up the ICV and used 2 others and getting the same codes.
crank sensor is VALEO and it was working fine on M52

[moatilliatta]

I’d run a genuine BMW crank and cam sensor.

This is the bulletin regarding the updated crank sensor.
https://f01.justanswer.com/jayputeli...ion_Sensor.pdf

So the crank sensor you have may need this harness depending on P/N

I’d check all your grounds and review the ETM if the DME is getting too hot
http://www.wedophones.com/Manuals/BM...g%20Manual.pdf

If you haven’t I’d cut out or replace the fusable link by the battery and replace the main and fuel pump relay to make use the DME is getting a solid 12v

[ForcedFirebird]

Hot DME and those codes will likely point to the 5v transistor that is shorting to ground. Easy test, see if you have a clean 5v at the TPS and crank/cam sensors.

Be weary when putting another DME in it's place, if the 5v is still shorted, it will ruin the new one as well.

[Northern]

Should be able to see the 5v rail voltage in INPA or any logging tool as well.

+1 for genuine cam/crank sensors

[Retrostudio]

Thank you guys i check the voltage first and already ordered oem sensors.

[moatilliatta]

Keep us posted to help the next guy out! :)