At least you've eliminated the CPS.

The pump is a 3 piston radial pump, so the fuel is pressed out the outlet by the 3 pistons, located at 120° intervals.
There is a bypass valve in the pump, which is controlled by a solenoid on the bump body. I believe the ECM must energise that solenoid in order to prevent fuel bypassing the outlet.
This would explain why little fuel was expected from the high pressure outlet when you turned the pump.

Actually it's worth checking that solenoid, as if it's not working, little fuel will go to the rail. Hyundai Ioniq 5 Ultimate. The replacement for the SE.
2009 Rimini Red SE TD4. Up for sale.
Gone. 2006 Tonga Green i6 HSE.

Is this the solenoid:




If it is that's what I've been referring to as the regulator and that's what I've changed today.

The fuel pump is a combined lift pump and HP pump.
That valve is what LR call the Volume Control Valve (VCV), which controls the amount of fuel passed to the HP elements from the integral lift pump. It's function is to maintain the correct flow rate of fuel to the HP elements of the pump, over varying engine speeds and loads.

The high pressure regulator is on the pump end of the fuel rail. Hyundai Ioniq 5 Ultimate. The replacement for the SE.
2009 Rimini Red SE TD4. Up for sale.
Gone. 2006 Tonga Green i6 HSE.

Right. Got you. When I looked it up I could only find it referred to as a Fuel Regulator and the sensor in the end of the fuel rail as the regulator sensor.
I bench checked the one on the fuel rail with with a battery. There was an audible click and I could make out the spring moving so I think that is good also.
Can the pump actually fail inside somehow? Is there anyway of checking that as they're not exactly cheap and the bill for this car so far is getting out of control chasing this issue.
Haven't tried the cam sensor yet so may have to do that.

HP fuel pumps can fail. It's not common for them to suddenly fail though, normally the just deteriorate over time. A mis-fuel event can cause sudden failure due to lack of lubrication, but that's normally pretty soon after the wrong fuel is used. Hyundai Ioniq 5 Ultimate. The replacement for the SE.
2009 Rimini Red SE TD4. Up for sale.
Gone. 2006 Tonga Green i6 HSE.

Hi Nodge
Don't you have a day off? 🤣🤣🤣🤣
I'm grasping at straws with that. It's just really doing my head in.now.
I've ordered another crank sensor (just incase the spare I had was a dud also) and a cam sensor. After that I think I'll have to get someone out to it, otherwise I'm just going round in circles getting nowhere.
The annoying part is that if you stripped all the sensors off there either wouldn't be an issue, or a quick ID of a mechanical problem or it'd still run but like s**t until the problem gets solved. I know they have plus points but can also send you down rabbit holes you needn't gave gone down!!!!! Technology though I suppose. The way ahead!!! 🤣🤣
Thanks very much for your help so far though. It really is very much appreciated. Cheers

Hi again
Well, I've got to the bottom of the problem. I couldn't understand why no fuel was circulating around any of the system when I cranked the engine. It's a mechanical pump so take away all the sensors and it should still at least push fuel through the inlet and back through the run off pipe?
So, I took the pump back off tonight and had a proper good look about. Here's a pic of the end of the cam:

In my complete naivety I thought that it was fine as it looks like the pump key slots in. However, on feeling around the black area between the key slots is jagged. I looked online to see what it should look like and it should be much deeper. So I have a bloody broken camshaft! I don't think that's something I could do. I've read a little about it and it's quite an involved job so I'll probably have to get a mechanic in to do it.
I really hate this car!!!!

Told you! I refer to my post of the 26th June!

An exhaust cam is a 4 or 5 hour job, but its not that difficult if you follow the manual.
I've got a spare exhaust cam in my stash, just in case. Hyundai Ioniq 5 Ultimate. The replacement for the SE.
2009 Rimini Red SE TD4. Up for sale.
Gone. 2006 Tonga Green i6 HSE.

Bossbob: you did indeed. I did look at it. I had to take a pic as I couldn't see into it properly and on the pic it looked ok to the uninitiated as it looks like the key will slot it. When I put it back together it did seem to slot back it so I thought it was ok. You live and learn!

A more important question might be, have you got all the broken off bits? If not, you’ve now got jagged pieces of camshaft wandering around in your engine.

Nodge: I had a look through the Haynes manual of pain last night and went dizzy starting one section to get passed to another section which passes you on to another three sections within the first three paragraphs!!!!!!! I'll have to do some more research and see if I can find a simplified explanation of the process.

Bossbob: in short, no. There weren't any bits which is why I didn't think it had gone. I've no idea what to do about it or where they're most likely to have ended up.

Not sure whether to give this up as a bad job!

Have a look here.
https://www.freel2.com/forum/topic10702.ht...am+failure
It goes on for 8 pages but Alex Pescaru is an expert on the FL2.
Good Luck!

Cheers. I'll have a good digest of it. Thanks everyone and apologies for going on a very wild goose chase towards the end. I let myself get bamboozled by electrics!

PK1968 wrote:

Nodge: I had a look through the Haynes manual of pain last night and went dizzy starting one section to get passed to another section which passes you on to another three sections within the first three paragraphs!!!!!!! I'll have to do some more research and see if I can find a simplified explanation of the process.

Bossbob: in short, no. There weren't any bits which is why I didn't think it had gone. I've no idea what to do about it or where they're most likely to have ended up.

Not sure whether to give this up as a bad job!