Td4 Smoke

The next stage in my TD4 saga (manual, 118k, 2003 52 plate) !
After eventually getting it started after a clutch change, I've been keeping myself amused fixing the window regulators. Now they are all sorted, I started it up again and noticed it smokes. There's a bit of bluey/grey smoke on startup which I kind of expected at 118k miles. But what I wasn't expecting was clouds of grey smoke when revving it. It seems worse if I hold it at a constant throttle for a while - clouds of grey smoke. But if I let it idle for a few minutes the smoke dies down and then stops, but it comes back again if I rev it.
It does not smell like oily smoke like from a knackered petrol engine, which makes me think its probably fuel related ? But its not clouds of black smoke like an over fueling diesel. When revved its mid/dark grey.
When I replaced the clutch I also replaced the crank case breather with the vortex type, I also painstaking cleaned the inside of the inlet manifold and fitted an EGR delete kit. It also had an oil change and a new airfilter. When it was apart I checked all the hoses and have replaced the two intercooler hoses at the front of the engine.
I've run the live data on my diagnostic tool and the only "strange" reading I'm getting is the fuel compensation number for cylinder 2 - at idle, the others are around 6 to 8. but cyl 2 is at 18 to 19. I've previously done a leak back test and it indicated no leaks.
Prior to me buying the car it had been laid up for about 6 - 8 months because of the clutch. I would not have thought the diesel would have gone off in that time ?
The only other thing I've read that got me thinking was a thread about unburnt diesel in the exhaust ? I messed around for ages trying to get it to start after the clutch change (it was a cam sensor) so would it have chucked fuel into the exhaust ?
I took it for a short drive this afternoon and it seems to go fairly well (short private road, so couldn't do much with it) - definitely not gutless or lagging.
Any advice on how to diagnose this would be most appreciated - I can't see it passing its MOT like this !

Put a couple of doses of Comma Diesel Magic with the fuel and give it a good thrash for a few hundred miles. That'll sort out a fouled injector.
It could also be residual goop from the inlet manifold.
Just drive it and see if it improves.

My current TD4 was similarly smoky, but a good clear out did the trick.

An Italian tune up ! Ordinarily thats what I'd try, but its SORN and the MOT ran out last week so its going to be tricky getting many miles on it. I put a stiff dose of Millers diesel injector cleaner in the tank when I bought it, so maybe a few runs up and down the farm track will sort it, at least enough for an MOT. Are you thinking that the compensation number on cyl 2 might indicate a fouled injector ? I guess if the fuel pattern from it is poor, that would cause it not to combust properly and hence the smoke. Thats what I'd be thinking with a petrol engine anyway, diesels are still a dark art to me

Erroneous injector compensation values are sometimes due to fouling of the injector. If the spray pattern is poor, the cylinder won't burn correctly. The ECU can monitor each power pulse and alter fueling to suit. The ECU can only add compensation at lower RPM. At higher RPM, it is difficult for the ECU to measure subtle differences, so it doesn't.
It will take a good few miles of hard driving to clear a fouled injector.
Is the EGR valve still active? If so block the vacuum pipe to it.

That seems to have done the trick ! I put a couple of bottles of injector cleaner in the remaining 1/2 tank of diesel and drove it around as much as I could on the farm. I didn't thrash it, just took it up to the red line a few times once it was warmed up and accelerated hard through the gears as much as I could. I stopped for a smoke check after about 30 mins and - nothing ! I gave it a good rev and still no smoke. I've let it cool down and then started it again - all good, no clouds of smoke anymore. Looks like it was a clogged injector and it seems to have cleared now.

Next on the list - a rumble at the rear, not a diff whine (had that on the 1.8 I used to have) so I'm guessing wheel bearing or maybe rear prop UJ