E320 95 - no Spark - Error code 24 on pin 8

[baudenfj]

Dear Forum:

My E320 1995 will not start! It is down now for over a week. The idle was not perfect and it rattled a little but if put in neutral it was very smooth. However, the car was hard to start one morning. Needed to be cranked over a couple of times and subsequently did not start the next morning!

No spark..

I replaced the cam shaft position sensor, ECU and OVP relay. There was definitely a problem with the OVP and the ECU only got power on one of the pins. Now since I replaced the OVP the ECU (and a second ECU) give me a consistent error of 24 and will not generate a spark. 2 month old coils and spark plug wires as well as spark plugs and O2 sensor.....

I now find my spark plugs to be wet so I know I get fuel..

What is my problem? I know error code 24 is the CKP sensor or magnet for position sensor not recognized.

I used an oscilloscope to measure the crank shaft position sensor output see attached trace. I get 5 spikes with approximately 5 Volts followed by a 6th spike with a voltage of about 13Volts. (see attachment) I assume the larger spike defines the position of the cylinder #1?

Car still has no spark..

Is this the correct output of the CKP? Remember I did not measure it loaded by the computer circuit. (High input impedance of the scope!) Should I measure it with the computer connected?

I also measured the voltage on the ECU pin from the adjuster magnet and get 12.7V! DO I assume correctly that the ECU is checking if this voltage is present?

What is going on why don't I get a spark. This mystery has to be solved one way or the other!

Here the mystery continue... !

If I reset the ECU I get a spark for two tries and then it is blocked and the error code 24 appears again...

I now put a scope directly on the CKP (yellow trace) and Cam sensor (magenta trace) pins at the ECU and measured the attached trace. It seems the senor output are correct but I am not sure about the timing!

I also checked the cam adjuster magnet. It has 5 Ohms resistance and if I ground it it will energize and I hear a click! It draws about 2 A.

Here is the catch! IF I energize the adjuster magnet the timing between the CKP and CAM sensor do not change! Is my adjuster magnet stuck in the position used at high RPMs? Do I have to open the top of the engine? Did anybody come across this?