# CIS-E Motronic Help (1991 Mk2 2.0 16v 9a engine)



## Sekele (Oct 7, 2013)

Hi guys, I am in desperate need of help in tuning and adjusting my CIS-E Motronic system. 

The short story is, my DPR amperage is always constant and does not fluctuate at all. As I understand it, this means that the DPR is not receiving a varying signal from the ECU and is stuck in a "limp-home" mode. With the ignition ON, the amperage reading is 1.3mA (according to Bentley it should be 90 to 110 mA). With the car running the amperage stays the same at 1.3mA. The only way I can make this reading change is by opening the throttle and closing it quickly; the DPR responds by dropping the current to slight negative values for brief few seconds (which is what should happen for deceleration fuel shuttoff). Other than that, I am stuck at the same reading of 1.3mA no matter what I do. 

To try to find out what the problem is I tired checking all of the inputs to the ECU. I found that my wiring to the oxygen sensor was bad; the O2 signal wire was melted and corroded. I cut that wire out and soldered a new one in, and checked all the inputs at the ECU again, and everything was within the specs specified in Bentley. However, I am unsure if I soldered this wire correctly. The O2 signal wire coming from the ECU had a wire within a wire. To my understanding the wire inside was the signal wire, while the wire around it was brought to ground in order to protect the signal coming from the O2 sensor? 

After verifying that all the inputs at the ECU are correct, I changed the O2 sensor to a new one and checked its output. The output was fluctuating and averaged around 700mV (rich mixture). I have also changed the DPR to a brand new one. All my fuel lines are new, the fuel pump is new, filter is new, injectors are also brand new. Dizzy has been replaced for a used working unit. I have checked the idle switch and full throttle switch using the VAG1501 harness, and everything was within specs. I have went over all my grounds and cleaned them, and checked their continuity; the car is grounded like it has never been before... 

I am running out of ideas of what may be causing this. The engine definitely responds to when I change the fuel mixture screw, but the DPR current stays the same. I managed to make the car run somewhat smoothly. it idles around 900-1k RPM, but experiences sudden brief fluctuations when letting of throttle and coming to a stop when driving; it's lacking fine adjustments that are performed by the DPR; it's stuck in limp-home mode in the same setting with no fine adjustments... 

Any help would be appreciated... help me before I go crazy.


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