Help D-Jet Mercedes M110 280CE

Did the first test with ECU connected. The fault is not there when i disconnect the ECU.
When i measure on the MAP pin 7 - ground there is no fault..

Mads

Also did a smalle video of what happens when i connect the MAP, it is very hard to keep the engine running..

Mads

Hi Mads,

was your idle-run contact on pin 17 closed when you did the video? If no, MAP sensor signals full-load to ECU and enriches mixture. That would then mean too little fuel. Checked fuel pressure?

I have just tested pin 17-12. (battery disconnected, ECU disconnected)

Throttle valve minimal = infinente ohm
Throttle valve max = infinente ohm

Should i do the test with ECU + battery connected ?
Thank you for your helt Volker..
Mads

No Mads,

have a look at my maintenance article how to adjust idle-run contact and fuel pressure.

Hi Mads,
the short-circuit (about 360 Ohms) between Pins 7 and 11 sounds familiar to me.

I once also measured such a value with an EFAW228 (special testing device from Bosch for D-Jetronic) on a bad-running car.

The reason for this phaenomenon may be the special internal or external wiring of the five-poled throttle-valve switch your car also has built in.
I didn't check this up to this time... no time to check it right now.

But he reason was in true a defective throttle valve-switch with a non contacting internal feeler-contact (the outer one).

Please remove your throttle-valve-switch and take off the cover. The switch is not so easy to understand and measure in built-out-condition because of the multi-functional switch and feelers in there, but you can clean it internal and check the conductor pathes, the feelers, the switch.and the feelers towards the connectors. Don't disadjust anything, just clean it carefully.

Then remount and readjust it following the instructions here on the page.

Maybe we found the reason for your problems...

Best would be to send some photos of the opened switch.

Regards
Norbert