BMW M5 92 S38b38 Wont start.

[Viddi]

Hi.
I have a M5 S38b38 that Wont start.
Car Wont start after the winter.
Disconnected crank sensor and plug it in again and start.
Start every time.
Next Day IT was completley dead.
I cant found a good messurment on the internet hos many Ohm the crank sensor want to bee.
Some tips any one?

[MarcoZandrini]

Isn’t still winter in Norway? You car is telling you it needs to hibernate more!

The first step in diagnosing a problem is to scan the engine computer (DME in BMWspeak) for codes. Is there a round 20 pin connector under the hood near the back of the engine compartment on the drivers side?

There is no such thing as a cheap BMW.

[bmwdirtracer]

When you say "IT was completely dead", are you saying the starter doesn't turn the engine, or the engine doesn't start when the starter is turning it?

The crankshaft sensor isn't a common failure part on this car, especially in the cold. When it does fail, it's usually from heat. I would suggest determining whether you have spark. Pull one of the spark plug wires, put a spare plug in it, ground the plug and turn the starter. Does the spark plug fire?

How old are the distributor cap and rotor? These like to gather condensation in the winter .

Also, if you disconnected the crankshaft sensor plug, is there any chance you accidentally swapped it with the cylinder identification sensor plug right next to it?

[Viddi]

Oh, the startet goes around.
But this engine have 6 coil.
So rotor and dis cap is not on this.
Yes i am sure thats contact not are swaped.
I traid to use a scantool to read out DME but the software faild, ebay shit

[dworthy]

Oh, the startet goes around.
But this engine have 6 coil.
So rotor and dis cap is not on this.
Yes i am sure thats contact not are swaped.
I tried to use a scan tool to read out DME but the software failed, ebay crap

Please note Chris's location, for the U.S. never received the 3.8l motor, they only got the 3.6l motor.

At this point in time I would recommend getting yourself INPA or a similar program to talk with the DME. OBD-I is sort of sketchy when it comes to codes, so be sure to take that with a grain of salt. Also would be worth googling "BMW TIS" for there are free places online that will have the value for testing the CPS.

You can still pull a coil out and test for spark on that motor.

@Chris, in MY-92 the European went over to the Motronic 2.x for the S-38 IIRC and it never went to the U.S. Market.

[bmwdirtracer]

Oops, I thought the 3.8 only started with the '93 model in Europe. (I had a '91 3.6, one of the best cars I've ever owned)

The question remains, though: do we have spark?
How about injector pulse? (You should be able to hear pulse with a stethoscope, or even a screwdriver held to the injector and the other end to your ear.)

If you have neither pulse nor spark, the DME is likely not getting timing info, so the crank sensor is a good likely culprit. Sometimes on this era, the sensor electrical plug starts to crumble.

Typical BMW crank sensor resistance values are ~560 ohms or ~1240 ohms. I don't know the spec for this car, but someone at M5Board E34 forum can tell you. (Tell 'em I sent you...they are a great group of people!)

Don't forget to check fuel pressure....

[Viddi]

Thanks for the help.
I work little on the car today, found corotion inside the DME printboard. Whil try to re solder and test it.