Too rich fuel from fuel injectors

Thank you Volker.
I had tested as you suggested. I measure the voltage in ECU using multi-meter, when they are all connected.

When cranking, the trigger contact output to ECU are as follows,
1) pin 13 against pin 12 = 1~3volts
2) pin 14 against pin 12 = 1~3volts
3) pin 21 against pin 12 = 1~3volts
4) pin 22 against pin 12 = 1~3volts

When cranking, the ECU output to injectors
1) pin 3 against pin 11 = 0.1volt
2) pin 4 against pin 11 = 0.1volt
3) pin 5 against pin 11 = 0.1volt
4) pin 6 against pin 11 = 0.1volt

I had plug some LED test light bub specialized for testing the signal from ECU to injectors into the injectors adapters. Yesterday, 2,4,7,8 cylinder light bub is on and with very strong light. But, today, none of the light bub is on.

What should I do next? Volker.

Thank you very much.

Hi Danny,

sorry I somehow misunderstood that you have a Mercedes-Benz 350. Now I read in parallel thread that it is a BMW. Which one is true? If it is a BMW you only have 2 trippger contacts on pins 21 and 22 .

However, 0,1 V on pins 3 to 6 is wrong. And it seems to be a new error as you had only partial failure before.

Sorry Volker.
I have 2 car (BMW and Mercedes Benz). This thread is open for my Mercedes Benz
Another thread you saw is about leakage on my BMW.

Volker wrote:
However, 0,1 V on pins 3 to 6 is wrong. And it seems to be a new error as you had only partial failure before.

I am confused and have no clue that it had started before, and it does not work intermittently. These days, it seems it is getting worser.

BTW, I am using multi meter for testing now. You suggested me to have an oscilloscope for better result. Can you recommend one oscilloscope for me?

Hi Danny,

I use RIgol DS1074Z. You need an analogue 4 channel oscilloscope. Bandwidth is not that important.

Thank you. I am looking it on my country's stores right now.