I broke my XKR! I'm completely restoring this XKR and I made a mistake ... I tried to fix 2 problems at once! Now it does not start, it cranks but will not start! Codes are p0102 (mass or volume air flow sensor "a" circuit low), p0112 (intake air temperature sensor 1 circuit low bank 1), p0122 (throttle/pedal position sensor/switch "a" circuit low), p0222 (throttle/pedal position sensor/switch "b" circuit low), p1122 (pedal position sensor a circuit low input.), p1222 (pedal position sensor b circuit low input)..... All of these codes may have nothing to do with my current problem. When the throttle body was disconnected I put the key into the 2nd position so I could check the gear shifter operation. I have cleared these codes and now nothing comes back except for p1000. It does still say failsafe.

Problem 1 was the gear shifter would shift out of park even when the brake was not applied, so I replaced the gear shifter. I double checked and all 4 connections, 2 white connectors on the drivers side, the white solenoid connector on the back, and the white/gray linear switch connector are plugged in. I marked the shifter cable before removing as well as taking pictures so it should be in the correct position.

Problem 2 was a hard start but it would always turn over and run fine after a few seconds. I noticed the nipple on the supercharger bypass actuator had broken off so I removed the throttle body to fix that and while I was at it I replaced the fuel pressure regulator.

And now it won''t start! What I've done:
1. Checked all the fuses.
2. Checked the battery voltage, 13v.
3. Removed the throttle body and double checked all the connections including the mafs near the air filter.
4. I tried pressing the inertia switch in the drivers fuse panel, it didn't budge so I don't think that is the problem.
5. I don't have a fuel pressure gauge on me but if I press the valve on the fuel rail a small amount of fuel will dribble out but it does not shoot out like I expected. If I remove the fuel pressure regulator fuel will come out for a moment so it's getting to there.
6. I swapped the fuel pump relay.


What to try next?

 

When you turn the key to the II position the fuel pump is supposed to run for 3 to 5 seconds to charge the fuel rack. Depressing the schrader valve should give a high burst as the fuel pressure is at 45 to 55 PSI.
Do you have the old fuel pressure regulator? If so reinstall it and see if the new one is defective. Not to speak badly about your mechanics skills but are you sure the new regulator is installed in the right direction for flow?

It would also be helpful to know the year and engine for the XKR you are working on. The early models are known for bore wash problems. Is yours a Nikasil engine?

 

Check the electrical connection to the air flow meter, by the air box, on the big intake pipe. This sensor combines air flow and air temp.

 

The mafs electrical connector? It is plugged in, nice and secure.

 

I have already tried installing the old fuel pressure regulator, same issue. There are 3 nipples of different sizes on this fuel pressure regulator, I don't think I could install it backwards if I wanted to. The nipple with black o-ring goes into the fuel rail, the jagged nipple goes into the fuel hose to the other fuel rail, and the skinny nipple goes to the supercharger correct? It's a 2000 XKR, I know they started swapping from nikasil that year. Is there a engine number somewhere so I can find out?

 

Supposedly around August 18th 2000 (xx000818 nnnn) but there's some banter about the exact date:
https://www.jaguarforums.com/forum/x...ge2/#post86201

 

The first thing to do is cure the fuel pressure problem. First remove the Pump 1 relay from it's position. Turn the key to the II position and give it 5 seconds turn it off and repeat a couple of times. This should let the ECU learn that the Pump 1 has failed and should kick Pump 2 in as the primary. Once you have cycled it try and start the car. Just in case you have bore wash press the pedal all the way to the floor and hold it there. That shuts off the injectors and you can crank the engine over to restore cylinder bore oil film. Crank for about 5 seconds stop and then do it again a couple of times, always keeping the pedal on the floor. After the third time crank as normal to start and while cranking slowly raise your accelerator off of the floor position.

If you are still in a non-start condition then you need to remove feed to the fuel pressure regulator, reinstall relay 1 and turn the key to position II and observe fuel flow. If you are not getting high pressure then it is most likely the fuel pumps are bad. It is also possible that the fuel filter is clogged and you might want to check that before condemning the fuel pumps.

 

Followed your first paragraph of instructions and still no start. Doesn't fail safe engine mode cut off the fuel pumps? Fuel pumps were done less then 1000 miles ago. Will try removing feed to the fuel pressure regulator here shortly.

 

Seems like I'm getting plenty of fuel pressure, this is how much fuel came out with key in position 2 for about 1-2 seconds.

 

Problem solved! The linear switch on the replacement gear shift assembly was LNC 6551 AC. The linear switch on the original gear shift assembly was LNC 6551 AA. This was causing the failsafe engine mode no start. Swapped the linear switch's and it started right up.