Hi all;

Have a 2000 XKR, 95k miles.

Im getting a restricted performance message and a code p1671. Car drives well and shifts well, no misfires no harsh idle it will just kick in the rev limiter if you push it hard. This happened before and could clear the code and restricted performance would go away with it.
but now it comes upon startup right away and I cant clear it. Heres what i've done:

clean maf
clean all battery cables and all fuse box power connections
new transmission ground strap to chassis
new positive battery cable
new battery
cleaned negative battery cables
all connections are tight; car charges around 14.3 volts.


Ive also tested fuel pumps and they both work, changed relays with known good spares as well. Now yesterday when i was changing the positive battery cable, started up car and let it warm up from cold and noticed both fuel pumps were on. Is that normal ? I though in a XKR secondary pump only turns on demand hence was thinking if its an ECU problem or if my accelerator kick-down switch is bad or other.

any thoughts?

 

Sounds simple but is you're thermostat working properly. Does you're temp gauge get to the middle of the gauge after about 5 minutes of driving? Mine was stuck open so the car wasn't getting up tot temp, it would eventually every now and then throw a restricted error message and the temp gauge would hit the overheated area even though the temps where really low.

 

Yes temperature is ok, raises correctly. thermostat is about 1 year old oem.

 

#My manuals state that fuel pump 2 relay is malfunctioning. Fuel pump relay 2 failure, fuel pump relay 2 to ECM circuit fault, fuel pump relay 2 coil power supply open circuit or ECM ground circuit fault (relay coil drive). So those will probably be the best place to start looking/

 

Ive checked relays and pumps
both work ok; relays are energized and pumps run.

the only odd behavior is both pumps are running at idle.

Ill start checking iat sensors and intake see if theres a vacuum leak.

 

It sounds electrical unless the fuel pumps are on their way out? Wiring problem somwhere or an ECU problem perhaps like you said but I don't think it's common. Last resort would be a Jaguar mechanic.

 

Those pumps are 4 years old and the car hasn't even done 10k miles on them ; but it may as well be the fact that they're not the best pumps out there.

 

It seems like having the 2 pumps run at idle and having this code are symptoms of the same problem. To my knowledge, the secondary pump only comes on when needed (load, rpm?). I'd say get the electrical guide from jagrepair.com and triple check the exact status of each of the lines to that secondary pump relay. It seems like the ECU at idle should be telling the pump not to run (does it?), but somehow the pump is actually running.