M42 won't start

[KenC]

One thing ive heard people complain about had been the crank ref sensor. ive never had an issue with it before [my m42 hasnt acted up in 50k and 4.5 years]

Its on the drivers side [i think] one lead going in, looks like a little black barrel. It could be gunked up, loose, or broken.

The CPS is pretty gunked up. It's not loose. The car has 280k on it and the CPS may be the original.

[Van Westervelt]

Fuel pump working doesnt mean its getting fuel. if the injectors are not firing, which would be a fuel management issue [sensors, ecu, etc.] then there is no fuel being delivered into the cylinder.

My point exactly. New fuel pump does not mean you are getting appropriate fuel delivery.

[KenC]

Fuel pump working doesnt mean its getting fuel. if the injectors are not firing, which would be a fuel management issue [sensors, ecu, etc.] then there is no fuel being delivered into the cylinder.

How can I check if the cylinders are getting fuel?

[Hick]

Remove the connection to an injector and check with an ohmeter. I dont know the exact tolerances but im sure someone on here cough:jordo:cough will chime in with them.

[KenC]

Remove the connection to an injector and check with an ohmeter. I dont know the exact tolerances but im sure someone on here cough:jordo:cough will chime in with them.

So if I swap in a known working ECU that should resolve the injector issue, right?

[Hick]

Not always. but if you want to take that approch make sure you disconnect the battery before removing/installing the ecu from either car.

[KenC]

Hopefully a swap of the ECU and CPS will allow it to fire up.

Can any one give me a quick rundown of how to change the CPS? I looked at it last night with a flashlight and it was so gunked up that I couldn't really see what was going on with it.

[KenC]

Can any one give me a quick rundown of how to change the CPS? I looked at it last night with a flashlight and it was so gunked up that I couldn't really see what was going on with it.

Bump thanks!

[Hick]

Remove it an replace it with another?

Im not sure if you have the right part picked out.

[restoration]

The fuel pump is working, I can only assume that it's getting fuel.

Haven't touched the ECU at all.

Take a fuel line off and get a bottle and crank it and see if it is getting gas, if gas comes out an there is no ignition, i would bet it is the ECU, i would ask someone with a 318is if you can borrow it?

[KenC]

Take a fuel line off and get a bottle and crank it and see if it is getting gas, if gas comes out an there is no ignition, i would bet it is the ECU, i would ask someone with a 318is if you can borrow it?

That doesn't necessarily mean that fuel is getting into the cylinders though.

A friend has a spare M42. We're heading out to try and get mine running in a few min.

[restoration]

That doesn't necessarily mean that fuel is getting into the cylinders though.

A friend has a spare M42. We're heading out to try and get mine running in a few min.

Thats what i mean if gas is coming to the lines there is fuel pressure but the ECU control when injectors open and close with the milage on your car i would not doubt it is bad. For sure good luck Ken hope it works

[KenC]

Update:

Swapped with two working ECUs - nothing

I tested BOTH the cam and crank position sensors and they're both WELL within normal ohm readings.

Main white relay is also functioning.

Cylinders ARE getting fuel.

Motronic pedal fault code = no faults

Any other ideas?

Has any one ever had all four spark plugs fail at the same time?

[Hick]

Whats the voltage in the system? Both cranking and not. Test it somewhere other than the battery.

[KenC]

Whats the voltage in the system? Both cranking and not. Test it somewhere other than the battery.

Any idea on where to test it?

What could low voltage indicate?