Engine lost power, changed SCV and now it wont start at all

[Navoffroad]

As title say. It wasnt revving above 1500 or sometimes up to 2000 rpm but its totally gutless.

No check engine light

2015 D23 twin turbo

I changed the SCV with a known good second hand one, straight off the motor of a crashed one, now it wont start at all.

I have tried to reset the ECU using the method in the manual (wait 3 seconds, pump accelerator 5 times, wait 7 seconds etc, hold down pedal 10 seconds....) but this hasnt even given me the confirmation that it has worked.

Can anyone shed some light to what I'm missing?

 

[Old.Tony]

Go back to basics. I'm assuming the engine is turning over and just not firing. It's not the turbo (there's no way the turbo can spool during an engine start anyway).

1) Prime the fuel system to make sure it's getting fuel. It should go firm in 4-5 squeezes, if it doesn't then you've got a leak and that might be all that's wrong with it.

2) Check the electrical connection to the SCV (unplug it, look at the pins to make sure they're ok, plug it back in).

3) If the engine is hinting at starting but not managing to keep going, it's possible that the EGR valve is stuck open and is flooding the intake manifold with exhaust gas. The valve is supposed to be closed during start, idle and full throttle operation. I suggest (because you can't just unplug it if it's busted) that you make a blanking plate out of something (I used 1mm stainless, but you can use 2mm mild steel or 3mm aluminium) and replace the gasket on the intake manifold end of the EGR tube and try again.