2006 XK8 with 127,925 miles....

I took my wife's XK8 out this morning for its weekly 25-mile romp to help keep it happy and healthy. The car performed flawlessly as usual. I haven't checked for OBDII codes in quite some time so I decided to do so upon returning home. My code reader displayed P0191. My JTIS CD DTC chart defines P0191 as "IP sensor circuit range / performance". Potential causes include a fuel filter / fuel system restriction, a fuel system leak, incorrect fuel pump output, and IP sensor failure....

What is the IP sensor, and where is it located? I did some searching here on the forum which essentially turned up nothing relevant. I want a better understanding of what I may be dealing with before I attempt to clear the code or proceed with any other actions....

Thanks for any assistance you can provide....

 

Likely Injection i.e. fuel Pressure.

Workshop manual & Electrical Guide etc say where - see JagRepair.com - Jaguar Repair Information Resource

 

I checked Gus' jagrepair.com site as you suggested. He shows a Schrader valve on the fuel rail of his 1999 XK8, but no mention of an IP sensor and certainly nothing for my 4.2 engine. So if the information I need is there, I missed it....

 

Jon, perhaps the IP Sensor is the black sensor on the right front of the right side fuel rail. The sensor at rear is the Temp sensor. That sensor sends PWM signals to the fuel pump module that controls the fuel pressure to a constant figure.. It has a vacuum line and electrical line attached. My sensor says FoMoCo.

 

Update:

Good call Kelly....

Google AI led me right to the IP sensor (which appears to also be called the fuel pressure sensor). It is mounted on the passenger side fuel rail at the front of the engine. Two 8mm bolts hold it in place. I removed it, cleaned up the electrical connectors with cleaner spray, and mounted it back in place. I will take the car out again early tomorrow morning when the temps are cool and see if anything changes. Mine has Ford part number 3R3E 9F972AA printed on it. I will not be surprised if it is no longer available from Jaguar, but it may still be available from Ford....

 

Jon, I suspect a 97-2007 Ford Crown Vic also uses this sensor. Not too expensive if you do not search JAGUAR. That Tax is too much, :-)

 

Amazon on

 

Hi Jon,
According to the EG it's at the front of the RHS fuel rail (your passenger side). Heritage shows its location:
https://parts.jaguarlandroverclassic...re-sensor.html

edit: Doh! late again...

 

Thanks Wayne. Looks like that sensor was used in just about everything Ford built back in the day. Would not be surprised if you have one in your 2003 F150....

 

No worries Michael. Always great to hear from you....

 

Update:

Took the car out for a 6-mile jaunt this morning. Came home and put my scanner on it. Code P0191 had cleared. Perhaps removing the sensor and cleaning its electrical connectors did the job, at least temporarily. For just $25 I think I will order a new one just to be ready in case I need it.....

 

Update:

Been about three weeks since the incident and the P0191 OBDII code has not returned. It appears that cleaning my factory IP sensor was sufficient to resolve the issue. I did order the $25 aftermarket replacement sensor and will hold onto it just in case....

Both the XK8 and I are enjoying the cooler temps and lower humidity as we approach autumn. Happy motoring to all....

 

Jon, that Black IP sensor provides data to the fuel pump module which is a PWM controller for the fuel pump.. This system
replaced the return line systems used thru 2002. 2003 fwd was a the single line and PWM driven fuel pump. the IP sensor read vacuum and fuel pressure to determine how fast to run the pump to supply proper fuel amount. The newer fuel pumps only run at a max 60%if needed so they should have longer life. Old Systems ran the pump at 100% continuously and re circulated the fuel so they did not last as long.

 

Kelly,

Good to know, thanks for the information. The 4.2 fuel pumps do seem to be more robust than the 4.0 ones. Fingers crossed that ours continue to run with no issues....

 

My 4.0 car still has the original fuel pumps 25 years on. What kills them is sitting unused being pickled in old petrol, rather than being given a good workout by driving the car.

 

Yep, these cars need to be driven on a regular basis to keep them happy and healthy....

 

^^^^^^ yes ! ^^^^^^^^^


although I’ve only had my 2002 XKR for 7.5 years, the volumes of previous owner maintenance records do not show any replacement of the fuel pump(s). So I’m saying the originals are still in there. And miracle of miracles, they both are working.

Z