D-Jetronic Problem!!!!!

Thank you for your help! Hope you all have a Merry Christmas ahead! Still have no reply from BOCH ECU customer center. I have came across one ECU repairing workshop online, Oldtimer-Steuergeraete ( www.oldtimer-steuergeraete.de/index.php/...onic/prices-shipping ). I am wondering if anyone here that has experience working with this workshop could share your feedback or comment? Anything I should be aware working with this type of workshop? Thanks!

Hi,

you should find a workshop that knows each and every function block and the reference values for testing it. Bosch Classic has them and I have them. Several claim to be able to repair but fail to verify if what they have repaired work in spec or not. So I clearly recommend Bosch Classic to you.

To be on the safe side you should find someone with a 350 Mercedes around you and swap ECUs.

Hi, hope you are well! I agree with you that I should send the ECU to BOSH for repairing, and that would be my top priority. However, there are some website issues happened that I am working closely with the BOSH customer service team to solve it right now.

As for swapping 350 Mercedes ECU, it would be difficult to find one in Hong Kong. According to your articles, it seems that you don't recommend people buying ECU on Ebay. Are there any other ways I could get one?

Btw, below are some checking information regarding all the connectors at the ECU:
1) Pin3 (1,5) with no signal
2) Pin 4 (4, with signal
3) Pin 5 (6,3) with no signal
4) Pin 6 (7,2) with signal

Do you think the above information is sufficient enough to tell that it is the issue of ECU, so that I don't need to find one ECU to verify it? or would you recommend other checking processes that I could carry out to further verify the ECU problem? Thanks a lot!

Hi Danny,

what I can tell you is that your symptoms describe that one branch of PWM in ECU is broken. Provided that this was measured on a running engine.

Thanks for your help! To your advice, I have sent my ECU to BOSH for repairing. The good news is the ECU has returned and working nice. Thanks for everyone's input, special thanks to Dr.-DJet! This forum has been useful and informative as always!

However, there is one follow-up question here:

After reinstalling the ECU back to the car, the starting and driving experience is great. However, the idling is poor. I tested the exhaust with gas analysis machine, which shows the CO when idling is very lean (~0.5%). Therefore, I tried to adjust the knob clockwise at the ECU. The CO did rise gradually. However, when the knob reaches the end, the CO stays at 1.4%. According to the workshop manual, the CO range should be 1.5%~2%. I have checked the idle contact at the throttle switch is closed, the intake manifold does not leak, and the fuel pressure is 2 bar, so i assume everything else are good,

Can I seek your advice on how can I raise the CO into the standard CO range? or did I miss anything here?

Thanks everyone again! Have a good day

Hi,

if it is not the ECU - which you say was repaired by Bosch Classic - then it is MAP sensor. However Bosch Classic also demands and tests your MAP sensor when they repair ECU if I remember correctly.