As Mark says could be no 4 injector but you need diags. i am in Manchester so not much help sorry

It's easier for me on face book. Am not on here much. I have nanocom am in irthlingborough but am laid up with flu at the Min.

You would have been better to come here before you spent any money. Not helpful I know!
Anyway, the guru on here for your car is @wammers and if he can't work out what's wrong then you might as well scrap it because nobody else will!

Anyway, my tuppence for what it's worth is are you absolutely certain that the glow plugs are working.
Point 1,some are of questionable quality (I think beru are the best ones)
Point 2 are they actually getting power.
Without good glow on at least 3 consecutive cylinders it will struggle.
That said, once it's started it should be OK.

So, you have fuel at the injectors. That doesn't mean it is there at the right time and pressure. Number 4 injector is important as it tells the ecu the point of firing and it can fail but often its the wiring to number 4 can give issues.
Sounds to me like you've got a timing issue. It could be lack of compression but as it seems to have happened suddenly I'd guess this isn't the case.
As has already been said, you need some diagnostic on it to get it going. Without that it's going to be all guesswork.
Good luck and stick with this forum as there is no better way to resurrect a p38!

What age is it? Is it pre-EGR?

Could be all sorts of things. Nanocom best to try and troubleshoot.

You need good glows (Beru are indeed the best). However, they need a temperature sender reading to work properly. Battery needs to be fully charged if it is an old bus as it needs quite high revs to accept the engine is actually running.

There's a map-pipe that goes from the fuel filter to the inlet manifold that sometimes splits.

Are the inlet hoses from the turbo all on and all tight?

In the Technical Sections there is a post with how to test the lift-pump is delivering enough fuel. See here https://www.landyzone.co.uk/forum/technical-archive.71/ ... except I cannot see the post. @wammers: where's your post gone with the EAS troubleshooting and the so much fuel delivery in so many seconds?

EDIT: found the fuel one here: https://www.landyzone.co.uk/land-rover/checking-diesel-fuel-pump-flow-rate.182959/

I have a similar problem with my Fiat Doblo and it appeared to be the throttle body and the throttle pedal... However, it turns out it's a wiring issue, more importantly, a problem with a plug/socket but I have never been able to find it (accident got in the way) so I am going to pick it up soon.

It does the exact same! Fires up no bother, but no throttle! No warnings so that's how I found it's a wiring issue.

My money's on wiring to No4 injector in your case. It's very likely chafed or simply poor (dirty) connectors.

Dunno why they cant simply use arctic wiring on vehicles, nice & soft, flexible and unlikely to snap through flexing...

Does the car have any form of booster box on it? The type of box that "improves power and MPG"! If so first thing I'd do would be to remove it and plug it all back to original.

I don't know the P38 but it sounds the same sort of setup on my L Series - ie direct injection with timing controlled by ECU using (among other things) a lift sensor on 1 injector and actioned in the pump.

I doubt this is a throttle position sensor issue as that would not affect starting. I doubt its a glow plug issue as that would not affect revs. I doubt its a crank/cam sensor issue as that should throw the EML. I don't know how reliable the injection pumps are on the P38, but my guess is this is something to do with the electronics in the pump or the wiring between ECU and the pump - ie the injection pump is not getting messages for the correct level of fuel or can not action them.

I'd think that could explain why its having trouble cold starting (ie its not putting in a bit more fuel for it to catch) and won't rev. If you leave it to warm up a bit, does it then restart OK? Check the wiring between ECU and injection pump. Take apart and clean all connections in that wiring and note any corrosion. I'm no Diag Jockey so don't know if it will be able to tell you if the pump is getting the right messages.

As I say, I'm not familiar with the P38. I'm also only familiar with the concepts of how these things work as I have a good solid reliable British L Series engine that does not go wrong - therefore I never have to actually fix it

Is there any wiring harnesses that could have been disturbed during the work done by the shop, it sounds suspiciously like some form of "disconnect" may have occurred sortly after your drive home, wonder if the bods from the shop actually went back over the work area on the vehicle when they were checking it out. Maybe even a disconnect at transmission could cause a no go.

It does sound a lot like your MAF sensor is at fault, won't show a code but needs cleaning.
Yes I know it's a diesel.

You need to get Nanocom on it with someone who knows how to use it. With those symptoms there has to be fault codes. Number four injector fault would cause limp mode and MIL lamp to be lit. But engine would still rev above tick over. Start by removing and cleaning pins on round plug from injection pump to harness. I was waiting for some dickhead to say change MAF sensor. You really do need someone on it that knows what they are doing.

wammers said:

You need to get Nanocom on it with someone who knows how to use it. With those symptoms there has to be fault codes. Number four injector fault would cause limp mode and MIL lamp to be lit. But engine would still rev above tick over. Start by removing and cleaning pins on round plug from injection pump to harness. I was waiting for some dickhead to say change MAF sensor. You really do need someone on it that knows what they are doing.

Click to expand...

Now now Wammers, you have to wait another 11 months before you can go off on one about MAFs - you're only allowed 1 every year

Not me saying it, or LZ - its your doctor

Even if the MAF does regulate fuel, and I doubt it on something as old as a P38, I'm sure the ECU would still let it have enough fuel to burn in 2.5L of cylinders at atmospheric pressure even if the MAF was broked.

GrumpyGel said:

Now now Wammers, you have to wait another 11 months before you can go off on one about MAFs - you're only allowed 1 every year

Not me saying it, or LZ - its your doctor

Even if the MAF does regulate fuel, and I doubt it on something as old as a P38, I'm sure the ECU would still let it have enough fuel to burn in 2.5L of cylinders at atmospheric pressure even if the MAF was broked.

Click to expand...

The MAF on a diesel engine, ANY diesel engine, is for control of EGR. Diesel engines ARE NOT fuelled subject to air flow through the MAF sensor. It is not possible to run one that way. Anyway good diag needed on OP's car.

As Wammers said you can leave out the No.4 injector as without it connected, car will still run.
Also, you can forget the in tank pump , without that you can run the car except when starting. You need to crank it few times before starting.
I have experienced both above cases on my car. Diagnostics is your friend.