Topic

So i have a t16 mems1.6 engine in my mg zr.  Yes it is converted.
it is a distributor type not wasted spark with the earlier 2gap flywheel i believe ecu is MKC101600. 
now my issue is that i have several invalid status issues in my live data and more importantly the car never leaves open loop.  Now as afr reports 0.44v 14.5 afr but this is a default as unplugging the o2 sensor i see no change and can see a different voltage on the lamda .55v that it reported.  Next i see crank sync is invalid value, and idle error is invalid.  So i dont know what is the cause or if in fact things like o2 sensor are like this due to open loop.  I have a full log i can attach but quick screenshot shows issues.   Ps.  Ive replaced o2 sensor with brand new original bosch square pin type for rover220 coupe from rimmers.  Original one was faulty but as i see voltage from this it seems ok to me?  What does crank sync do? Or do some models like difference between 2 gap and 4 gap flywheel mean not all report this im not sure?  
ive got dual channel oscilloscope on it and can see a crank sensor regular output just fine.  
Other than this car starts and runs fine just running slightly rich at moment which i can see from a seperate wideband guage installed for later tuning.   
thanks trev.

 

Hi Trev . I don't claim to be an expert on this sort of thing but are the earths on the car ok . ZR's  are getting a bit long in the tooth now and it does remind me of a fault I had with my ZR . It turned out to be bad earths that were giving the ecu a headache . 

John 

I think that oxygen sensor voltage is supposed to fluctuate between 0.1 and 0.8 volts, not just sit at 0.44 isn't it?

Correct it does fluctuate 
the reading of 0.44v is actually given out by the ecu itself when in an open loop state.  Effectively during startup before the o2 sensor is up to temp which is something like 500degrees the ecu has to perform in open loop mode.  Otherwise it couldnt use other sensors as they would be invalid.  Its like the old automatic choke in old cars.   My problem is that when it gets up to temp it should come out of open loop and start using the real values from o2 sensor etc.  Any one know the list of items that dictate open loop in the mems1.6 ecu?  Im assuming coolant temp, o2 sensor temp are there any others?  I want to rule them out one by one.   Im gonna swap loom over to test as i think there maybe a strange earth issue.  What i mean is that when starting the car it nearly always starts the car fan. Just as if the car was too hot or the coolant sensor was unplugged after 30s it turns off and works as normal with engine temp turning it on and off.  Unplugging the sensor also turns fan on.  So I'm assuming some fluctuation during startup...  if anyone has any ideas would be appreciated but im assuming some in depth knowledge here or something that has had same issue. 

Quick addition... so i measured o2 heater and found no voltage.  Fuse13 10amp was fused... fixed now o2 sensor is fluctuating as it should sitting at about 13.5 afr 0.62 volts. Its rich... now the ecu readout shows 0.44v and doesnt agree with the real reading.   Now i think this is because its open loop still.  So i want to concentrate on the other things now and rule them out.   What is crank status not synced mean?   If i pull off cam sensor it starts but rpm is very low.  I assume it wont start at all without crank sensor.  But why out of sync?   Idle status is also showing error i dont know if they are related....