I have an XK8 with only 14,000 miles and I experienced the same issues with the car stalling and showing P191 and P193 codes. The FRP Sensor was replaced with stil the codes came back. Car recently stalled then finally restarted. I am now told it may be my fuel pump since it is not driven much and is pretty hot where the car is. Any thoughts on replacing the pump?

 

Use the forum search function for the X100 forum as this issue has been covered many times.

Connect to the vehicle PCM using a smart phone and the Torque app via the OBD port with a Bluetooth adapter to read fuel pressure. Should be 3.3 bar (330kPa) at idle.

 

Neil: You posted your initial post (a diagnostic question) to a thread already labeled "resolved" and skipped making the usual (and expected) "intro" here:

New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

 

Welcome to the forums Neil,

I've moved your first post from the end of an old RESOLVED thread in S-Type forum as a new thread in XK8/XKR forum. This is the place to post technical questions about your model.

Graham

 

Those codes mean the fuel pressure at the rail as measured by the sensor is sometimes too low and sometimes too high for the sensor to pickup. The fact that it is sometimes too high means the pump itself likely works, but there is likely some issue with aging gas on the rest of the components. This is a return-less system. The fuel pressure is of course generated by the pump, but the pressure is regulated by PWM, based on the input of the sensor. There is also a pop valve built in the pump to release pressure when needed (sudden deceleration). That pop valve is likely stuck/frozen with old gas/varnish.

Best is to open the gas tank and do a visual inspection from the top (easier on a coupe). If everything is clean, dump the gas, replace the filter, and use a known-good injector cleaner along with a fill up. The cleaner might do its thing on the pop valve and free it. If not, the pump is unfortunately an assembly for $$$.

If things are ugly in there (rust, super old gas), then you are looking at substantial repairs. I would think throwing injector cleaner in a mess like that would only serve to push ugly stuff further up towards the engine and make things worse.

Feel free to elaborate on "the car is not driven much". There is a world of difference between a car driven a tank or two a year and a car sitting there for 5 or 10 years, trust me.

Best of luck, keep us posted.