I can't wait for your video results but I do believe you will see a reversed rotation due to residual compression. I have been attempting to find the reason for the harsh shutdown of our CRD since we bought it a year ago. I am willing to spend the $$ to smooth it out.

My FCV has been dead since 40k miles or so(at 111,000 now). I run with it unplugged all the time to prevent the buzzing noise it makes when it fails. There is a slightly rougher shutdown without it, but nothing you notice unless you compare the vehicle side by side with another that is working.

I would also like to note that the 2002-2004 diesels do not have a FCV.

IMO, just unplug it and move on, no need to waste $$$ on it when you already have your MAF unplugged. If you ever need to pass a emissions/inspection and need the CEL off you can just plug it back in at that time.

Is there any (easy) way to know if the FCV is dead or not working properly ? Do you get any CEL or ECU error when the FCV stops working ?

Of course, you can always check for codes whenever you suspect a problem but I'm pretty sure that if your FCV is still plugged in there will be no code.
The FCV usually fails because the gears get stripped. In this case, the motor still functions but the flapper doesn't move and the ECU cant tell the difference.
You could even remove the flapper from inside the FCV and the ECU still wouldn't know.

I suggest getting a plate to block off the tube that goes from the EGR to the intake elbow.
Or better yet, go to https://shop.sasquatchparts.com/ and buy the stage 1 kit.

So basically the only way to tell if the FCv is in good working order is to remove it and inspect it ...

I have a 2010 Jeep Wrangler CRD, not the Liberty...

Yes.
But you could also remove inlet hose at the engine intake, look to see if the valve is fully open, and use your fingers to try and close it. It should spring back open.
Other than that, remove it and do a bench test. Apply 12volts to the motor and see if it closes.

Joseymcwales,

That picture is not of a 2.8L Jeep Liberty, what vehicle do you own.

And how did you manage that?

Ma questa e una meraviglia.

Lavori in Italia?

Vivo e lavoro in Italia e vengo in vacanza negli US