Location of the fuel regulator, on the 2002 XKR

My XKR100 always starts but it takes longer that it should, 5 to 8 seconds cold and perhaps half that warm. I’m hoping it’s the fuel filter or fuel regulator under the bonnet.

First thing to try is cycling the ignition key a few times without trying to turn the engine over.this primes the fuel rail. If the engine starts quickly then its likely the non return valve in the fuel line has failed and is allowing the fuel pressure to leak down.

1 Like

Does it have the nikassil lined block? Depending on how cold youre talking about, mine does take a few more rotations to start when really cold outside. I put it down to metal contracting and the motion causes enough friction to make things expand that fraction of a hair and it fires. Of course I could be completely wrong lol. My 97 will fire within 2 rotations usually when warm outside, but can take several more when its cold outside

Thank you for your response, I will try that. Just had the engine rebuilt from soup to nuts. New kevlar belts rebuilt the super charger. Nothing under the hood was left undone.

So im being gentle with her while everything works together. I also redid the exhaust, with a borla muffler and catback system, so she sounds amazing.

Except for the hard starts, she’s Aces. The fuel pumps are loud. There is a noticeable whine, (kinda sounds cool, really because it sounds like a turbine winding up), but not all the time. Besides that and the hard starting there are no other fuel pump signs of failure. I have already changed the fuel filter, with no noticeable change. So before I drop the tanks, I want to address the FPR. But l honestly don’t see it. Is it under the supercharger somewhere?

The FPR is different to the non return valve, the FPR will be somewhere in the engine bay but the NRV will be in the tank I think.

I know the 2003 with the 4.2 does not have a FPR, it uses a different system. I’m almost certain the 2002 XKR 4.0 does, but I don’t know exactly where it is (must be on the fuel rail somewhere). So far I haven’t been able to find a reference to where it might be.

1 Like

The 4.2 uses a RETURNLESS SYSTEM. The fuel pump speed is varied via PulseWidthModulation.

Not sure why we are talking about the FPR my suggestion was the NVR.

I am pretty sure that’s not it. Looking for the location of the FPR on a 2002 XKR. The part exists so it must go somewhere.

Have you actually tried the key cycling to see if it improves the time taken to start the engine???

Yes, it is one of the first things I tried, before switching out the fuel filter out of an abundance of caution.

It always starts, just not right away. No noticeable power loss at excelration. The fuel pumps do whine a little, but sometimes not. I haven’t checked the pressure at the rail, and I don’t know where the FPR is, there is an FPR part for this vehicle so it must be somewhere, it’s got to be around the fuel rail somewhere.

Do you see something that looks like the item pictured in this linked diagram?

Terrys Jaguar Parts: Fuel Rail Injectors and Regulator Naturally Aspirated


Wow, that’s the part! Thanks for that, and that’s exactly where it should be, but I didn’t see it. It must be under the supercharger.

Much appreciated!

Sorry, I missed the XKR100 model you listed. The supercharged model is different.


The FPR doesn’t seem to be listed as a separate part though I believe it is in the same general location on the fuel rail as the normally aspirated version. Terry’s doesn’t have it either.