Hey there,
I don't know anything specific to help but this is what I could find...

Evaporative Emission Control – P0443
Model:
Jaguar XJ 1996, 1997
Complaint:
The fault code P0443 is likely to be set due to a fault in the EVAP purge control valve circuit in Bank A.
Remedy:
Ensure the code P1111 has been logged after the service drive cycle has been completed. If this is not the case then go to step 7 of the test below.
Check the harness and connectors to ensure they are in good condition and are reliable. If they are faulty then either repair or replace and go to step 7 of the test below.
Turn off the engine, disconnect the Bank A purge valve and go to step 1 of the test below; if no faults are found.
Test: [ul][*]Check harness continuity PI 018/001 is correctly wired to RS 006/005. If this gives a positive result, go to step 2. If the circuit is open then find and repair the wiring fault, re-connect the harness and go to step 7.[*]Check harness continuity PI 018/002 is correctly wired to PI 047/034. If this gives a positive result, go to step 3. If the circuit is open then find and repair the wiring fault, re-connect the harness and go to step 7.[*]Check harness insulation PI 018/002 will complete a circuit to Vbatt. If this gives positive results then switch on the engine and go to step 4. If the circuit shorts then find and repair the wiring fault, re-connect the harness and go to step 7.[*]Ensure the voltage level at PI 018/001 reads at Vbatt. If so then go to step 5. If the reading is less than Vbatt then find and repair the wiring fault, re-connect the harness and go to step 7.[*]Ensure the resistance value of the Bank A purge valve is within 22 – 30 Ohms. If the reading is within these limits then go to step 6. If the reading is out of limits then replace the valve, re-connect the harness and go to step 7.[*]Ensure the purge valve is operating correctly. If this gives a positive result then re-connect the harness and go to step 7. If the purge valve is not operating correctly then replace the valve, re-connect the harness and go to step 7.[*]In order to check if the fault code has been cleared perform the service drive cycle. If this gives a positive result then stop. If the fault is still present then go to step 8.[*]Repeat the diagnostic procedure. If this now omits a positive result then stop. [/ul]This was found here...

OR

I t means you have something wrong with your emissions. Check the hose that goes from the Evap Valve (usually a round plastic valve) to Throttle body. Maybe is too soft and when there is a vacuum it clogges.


Sounds like you should check under the hood and make sure everything is connected (tubes in the engine bay)and what not. Make sure everything is connected, not crimped, not cracked and is clean. Let us know if we can help some more. Perhaps a technician will come in to help you.

 

I will assume the engine is cranking over. If that is the case then check for fuel and spark. Can you hear the pump coming on when you turn the key? Checking for spark would be tricky with the coil on plug but my gut tells me if it was electronic you should see other codes tripped. I would start with something in the fuel system that is freezing while it is outside. Electronics tend to b e intermittent when hot not cold. How many miles? Have you changed the fuel filter recently? Since you did the plugs you would have had to remove the intake. I would double check all connections. Attached is a picture from the JTIS that shows the connections on the intake for the fuel system: If you refer to the pictures they match to the numbers below. The text below is from the JTIS as well.


Fuel Charging and Controls
1 Fuel charging wiring harness
2 Fuel injector
3 Fuel pressure sensor
4 Throttle body
5 Fuel injection supply manifold
6 Fuel temperature sensor
The electronic returnless fuel system utilized has the advantages of reduced fuel tank vapor, requires less electrical power and does not require a fuel return line.Fuel is supplied at high pressure to the injectors via a fuel rail which incorporates six fuel injectors, a fuel pressure regulator and a fuel temperature sensor. The Powertrain control module (PCM) maintains 380 kPa across the injectors, by increasing the pulse width modulation signal to the fuel pump controller. This in turn controls the voltage output to the fuel pump. The use of supplementary oil or fuel additives is not approved unless specified by Jaguar Cars in the form of a service communication or directive.A fuel pressure relief valve is fitted to the fuel rail at the front of the camshaft cover. This valve allows the fuel system to be depressurized during servicing and troubleshooting.

Let us know what you find out.

[IMG]local://upfiles/3130/81B91FCEB67547A5BCA0C97485486829.jpg[/IMG]

 

Hope you get it figured out...sorry I couldn't help you further...

 

Sounds like the fuel pump is bad. First replace fuel filter(cheap and easy). Pour a can of Sea Foam engine treament according to your fuel amount into your fuel tank. Try and drive that tank near out and fill again. This cleans whole fuel system miraculously. If same problem exists it may be the fuel pump. If you have ever run out of gas on this car that can damage your fuel pump.