K11 Crank but no start

[Benjsy]

Hi all,

I have a K11, CG10 Micra that was running perfectly and then the other morning, crank but no start.

I have tested a couple of things but just wanted some info if anyone can help.

Snap-on Machine in the OBD2 port gave a P0340 Camshaft Position Sensor Problem Bank 1.
looking at live data i get 0 RPM reading when cranking.

If fuel is added to the Airbox / throttle body the car will start and idle and then die quite quickly.

I have tested the coils and im getting 12v to them on both the Green and Yellow Wires. and because it starts with fuel added im happy it has spark.

The injectors have 2 wires, both are getting 0.62 volts when cranking i would presume they need 5 or 12 volts to fire.

so, My main question is, would the cam sensor fault cause the injectors not to fire?

if so, everything is pointing to the faulty Cam sensor.

i have tested the wiring leading to the Cam sensor, and im getting 5 volts on the green/yellow with the ignition on, i am presuming this is the feed. The Black is Grounding fine, The white and green is 0.6v when cranking. im not sure if this is all okay or further points towards faulty Cam Sensor.

again would the cam sensor stop all injector function?

any help much appreciated.

Thanks.

 

[villanueva_00]

Late Micras have Camshaft and Crank position sensors. In theory the Camshaft Position Sensor is only needed to determine TDC on the engine so if this sensor is bad the engine doesn´t know in which part of the cycle it is. However if crankshaft sensor is good, you should at least have RPM and the ECU can ran on wasted spark and batch injection.
I dont know much about Facelift Micra ECUs but if you are not seeing RPM on crank thats pretty strange if the Crank sensor is working.
So i would also check the crank sensor as per the manual.

 

[Benjsy]

Thanks for your reply. The car went to a small garage / mechanic to look at at the time of breakdown, he has changed the crank sensor already as this is what he presumed the fault to be.
I may price up a genuine cam and crank sensor just for price of mind. But I'm not convinced it's the problem.

Thanks.

 

[Benjsy]

I disconnected the newly installed crank sensor and turned the car over with added fuel and it wouldn't start. as soon as i re-connected the Crank sensor it would start again with added fuel so i am happy the crank sensor is working somewhat.

 

[villanueva_00]

So if you´re not getting any fuel i would try and disconect the tube from either the filter output or input to the rail to see that the pump is working.
If it is working then i would check the injectors, taking a reading of what resistance they measure. Then i would also try using a big flathead screwdriver and placing it agains the injector to try and hear it clicking when trying to start over.
Also check fuel pump relay (you gotta hear the pump prime when ignition is on) and fuses.

 

[Benjsy]

I have got fuel to the rail the problem being electronic, I am not getting any ( very little ) Voltage to all injectors, so they are not firing. for all 4 to go at the same time its pointing towards ECU or maybe something else.

just to make sure i changed the cam sensor for a new one and still no change. i also have a fault for a Mass Air Flow Sensor and im getting 0 volts on the scanner for the MAF. does the injectors, MAF and Cam sensor.

Seems as though the injectors and Cam Sensor are getting this mysterious 0.5 / 0.6 Volts where they should be getting 12 or 5 ?

Thanks,

 

[villanueva_00]

It´s really hard checking voltage on the 2 plugs of the injector with a multimeter (As it is a pulse signal and ideally it should be checked with an oscilloscope).
However one of the pins of the injector plug goes straight to a fixed 12V (with igntiion on this pin should always get 12V).
The other pin goes to the ECU (4 independent pins for each injector) whick is the control ground to set the necessary pulse.
Chech the 12 Volts on all 4 pins. If this is okay then the problem should be either the wiring to the ECU or the ECU itself.
*Check the injectors with a 12V battery and ground and try and hear them click when you ground them to see if they seem to be working okay*
I put the schematic below so that you can see that the right pin (plug clip facing up) is the 12V source and left pin is the ground for the ecu.

 

[Benjsy]

villanueva_00​

Thanks for your info ! I should be able to trouble shoot with this and get a bit more of an Idea. I shall update with any progress.

Much appreciated !