Hi everyone! I had a 4.2v8 Jag XF, now its turn for 3.0SC Awd and just at begining I have a large problem. I would be happy if anyone help me.
When I start the engine at cold it starts with problem and not works fine. After aprox.30sek it gets better. I did by sdd software litle reaserch. At start high pressure jumps from 2MPa to 7MPa and thats the time when engine works not correctly. After aprox 30sek. Pressurre jumps to 21 MPa and engine works fine but... i read by sdd desired pressure and it is 5-6 MPa so it looks that my pressure is to high. Another observation is fact that when engine reach 3000rpm pressure changes and it is like a desired pressure 6-8 MPa. When rpm goes down the 3000rpm 21MPa back to 21MPa.
Trouble codes which I read by sdd is: P053F-23, P053F-24, P228F-85, P228E-84.
I tried to do a high pressure test but it fails.
Engine has been rebuilt after timing system problem.
One high pressure pump has been switch from another car which works fine, another one has been bought brand new but no changes seen.
Any ideas? What could be wrong? My mechanic gave up...
I suspected a shaft which powered high pressure pumps but mechanic said that there were marks at the engine and shafts and couldn't do anything wrong.

 

I assume by this, you mean that you suspected the fuel pump timing could be out, but your mechanic is pretty confident that he timed it right.

To be honest, given that the timing chains have been worked on I think fuel pump timing is most likely the problem here so I'd definitely want to check it. There's a documented way of checking the timing is correct using a special tool - you need to remove the vacuum pump so you'll have to drain the oil, but you don't need to disassemble the engine or anything to do this, so it's worth doing. I don't have a service manual for the 3.0 v6 but there's one kicking around on the forums, and I imagine that it's much the same as the procedure for the 5.0 v8 that I have. You can probably also use the fuel pump tool for the 5.0 v8 of which there's loads of copies on eBay.

Also, check that the in-tank pump is running correctly - you should be able to feel it on top of the tank if you lift the access panel under the rear seat.

Beyond that, I guess the remaining suspects would be a faulty fuel tank purge valve or EGR valve, but honestly my money's on fuel pump timing.