My X300 is misbehaving and I need some help. The engine will just shut down, usually when warm and when on low throttle. before it dies the throttle dos not respond and it dies. It will also put the transmission light on and into limp home mode, not every time though and after turning it off again it comes back. It can be hard to restart and it slowly comes back to normal idle and running. The economy is as it always was 13.5-14.2 round town. Idle is good and normally it starts first hit.

What has been done. Well, fuel pump replaced, pressure is good. New crankshaft position sensor, cleaned the throttle body and new position sensor. The connections on the relays behind the front lights Drivers side cleaned and checked. OK. 98 fuel used always.
Transmission control unit changed.

Car has always been cared for, now has 185,000 km.
Any ideas and experienced great fully received!

 

Mine does the same thing. What are your idle RPMS in park and in Forward/reverse gear?
I was told by a local Jaguar shop that my TPS is bad, waiting for a replacement to arrive. Does your car miss at idle, or does it idle fine? Mine misses, but the insulation on wires to my ignition coils is falling apart. I will need to replace the wires.


Transmission light gets illuminated if the engine stalled, which may or may not be transmission-related. It's confusing. If there are no transmission-related symptoms I would not worry about transmission.


Well, since you replaced everything else, I would look at Idle Air Control valve (Aka stepper motor). Next I would look at EGR and secondary air injection. You disable EGR by making a "gasket" with no hole in it for the back of the exhaust manifold, where the EGR taps the exhaust gases.

You can disable the secondary air by pulling the plug from the air pump (Check engine will illuminate).

My approach: first ensure that things that matter work as they should, next disable the worthless smog-related bolt-ons until I find the one that causes the car to stall.

The air pump is only supposed to run on startup of a cold engine, and only for a particular outdoor temperature range. I have seen it run on mine, when the engine was hot (coolant fans running). I don't know whether this is a coincidence or not, at least not yet.

 

Hi Jaguarx300,

Limp Home Mode (LHM) is often associated with a malfunction of the Throttle Position Sensor (TPS). When your new TPS was installed, was it calibrated with the dealer-level system? If not, you may just need a recalibration.

Another issue that can contribute to engine stalling is low transmission fluid - I don't think that's your primary problem, but it could be a contributing factor so worth a check.

Please keep us informed.

Cheers,

Don

 

Yes the trans fluid is a little bit low. the TPS was done by a Jag Specialist with the computer equipment. I will top up the trans fluid and see how it goes. Thank you. David

 

I would drain and refill if the fluid is old, inspect the fluid for wear products (metal shavings) and replace the filter. I am not a big fan of using machine to flush an old transmission, because the worn out rubber seals can get damaged by the excess pressure generated by some machines.

BTW, extra drag generated by a faulty transmission can cause the engine stall. What are your idle RPMS in Park and in Drive or Reverse. The idle RPMs in Drive or Reverse are supposed to be higher than in Park. If they are not, I would try to find out why.

 

I had this problem with my Jag but after I cleaned my TB it was fine, and on REALLY hot days I will get limp mode randomly but having straight pipes out the sides with many electrically workarounds probably doesn't help haha!

 

Hi Nemesis,

Welcome to the Jaguar Forums!

Please visit the New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum and post an introduction to let us know about yourself and your Jag with straight pipes out the sides.

Cheers!

Don