Attempting to bring my wife's '99 XJR out of winter hibernation. The car fires right up, settles to normal idle and shuts down immediately. The fuel pumps have been replaced, and the symptoms are different than a failed pump. It's not a slow run down for lack of fuel pressure but rather feels like the ignition is being switched off. The check engine telltale is on. This car is also my template for assembling an XJR transplant into a Mark 2, so it's possible I disconnected something and failed to reconnect it over the winter, but for the life of me I can't think what that could be. Any thoughts much appreciated.

 

if it has a CEL, and you disconnected something, the codes stores will probably tell you what is disconnected

 

+1 on the codes first.

 

You could check if it's when it tries to go CL (closed loop) and then suspect a sensor it starts to trust or a leak it can't correct.

If it relates to CL it ought to happen sooner on a 2nd start attempt (as the engine is somewhat warmer).

 

I hooked up my scan tool but can't link to the car's computer. The Innova tech suggests the car is in limp mode, and to get the car running to read any trouble codes. Don't you just love techs? Any further thoughts welcome.

 

It should just work but some tools just don't. Try something else? Or start part swapping.

 

I doubt it's the scan tool since it's worked on this vehicle before and currently works fine on the '01 XJR I've planted in the Mark 2. Any idea what might block the connection with the ECU? Thinking this may be the cause of the shutdown. Thanks for any ideas.

 

There is a fuse for the OBD plug. I don't have a manual so I can't look it up, but I'm sure someone here can help.

 

Please include these sorts of details in the first place. They show you're now looking for a fault in the car's OBD system. Use the workshop manual for help on fuse(s), wiring etc.

 

Mine has done this a couple of times, and on further investigation, I found that the ignition key was actually popping back to the accessory position and turning the engine off. I think it happens when the ignition lock gets worn.

When it has stopped, check the position of the ignition key.

 

Worth knowing. Yes it'll then not talk OBD.