I have a V8 supercharged and have had it for a few years and everything has been fine. The vehicle had an accident where someone decided to drive into the rear end, it could be a coincidence but shortly after I have a problem in the mornings on a cold start.

If you start the car from cold and don't touch the accelerator the engine will misfire and go into reduced power mode and run real rough, however if you push the accelerator to the floor and go through the rev range you get a little splutter then the car runs all day perfectly until the next morning.

The EML light is on but if you reset it it don't normally come back on for a day or 2.

Codes, apart from the usual the only engine related faults are P0088-00 Fuel rail/system pressure - too high.
I have changed the high pressure sensor on the fuel rail but has made no difference. The high pressure fuel pressure is showing at 11970 Pa and 2.3v

I'm hoping it has not slipped the pump timing chain so does any of you experts have any ideas/experience of the above.

Look forward to your help

Have you tried a decent fuel system cleaner?

I used a Forte injector cleaner when the car had less than a quarter of a tank but didn’t really make any difference, i also have used super unleaded fuel, all the same.

have you had a gander at this

https://www.autoblog.com/2016/03/28/p0088-...5VsmAO1-Vk

as you had a rear end repair is it possible the fuel line has been compromised? 2012 Vogue 4.4 TDV8 - Current
2014 Navara V6 - Gone
2004 Vogue TD6 - Gone
Grand Cherokee - Gone
Discovery V8 (LPG) - Gone
Discovery TD5 - Gone