Hello,

A couple days ago the check engine light came on and later I had some issues with the car starting. I took the car to the dealer service and they indicated the fuel pump needed to be replaced. I wanted to get second opinion on whether you guys think this may really be a fuel pump issue? Vehicle is 2007 XJ8 with 75,000 miles on it.

SYMPTOM:
Check engine light came on but had no immediate issues. Couple days later I drove the car to the store, no issues. But leaving the store, I tried to start the car, the car would crank, the engine fires but then dies-- then 2 lights are on while in this state: check engine light and the low oil pressure light. In this state, the car has no power steering and it seemed the brakes were not working. After a couple tries, the car started normally and I drove home normally and didn't notice any abnormalities. Check engine light was still on.

I took the car to the local Jaguar dealer and they told me the code came up as fuel pump needs to be replaced. I declined service because they were vague on how they determined exactly the pump was failing. Obviously it didn't completely fail because I could drive there. They didn't do any work but cleared the check engine light. I drove home with no issues.

A week later after 3 or 4 short trips with no issues, the same issue happened again. And again, after couple tries to start the car, it started normally. This time the check engine light didn't stick-- it's off now.

Question:
So I'm wondering if you guys think this is a fuel pump issue? maybe it's getting close to end of life but has not died? If so I'll order a pump and have a local mechanic replace it.

Thank you in advance.

 

Just a suggestion, but why not buy a relatively inexpensive Jaguar-specific code reader like this:

https://www.ebay.com/itm/iCarsoft-LR...0&shqty=1#shId

It will give you all of the Jaguar specific codes for diagnosis purposes, then if you DO need the services of a Jaguar Dealer in order to fix it, at least you could go in with your eyes wide open?

 

I'll get this OBD reader since I'm looking to take care of this ride long term.
I wasn't sure the symptom I described means it's a fuel pump issue or some fuel issue closer to the engine side? The car has never stalled while engine is ignited... which to me is weird because if it's a pump issue then stalling should be just as likely.

Anyway, I actually may do this my self. One thing I've noticed is the fuel pump drawing in the 2007 XJ8 service manual does not match the replacement fuel pump according to Dephi.

This is from the service manual, you can see the fuel connector is an elbow and there is a wire harness coming out:

From 2007 XJ8 service manual. Note the elbow connector and wire harness



Delphi replacement pump according to catalog for 2007 XJ8. But notice there is no elbow connector and no wire harness- the connector is recessed.






However, if I search in the Delphi part catalog for 2005 XJ8, this is the par that comes up. You can see it doesn't have an elbow for the fuel line and no wiring harness. The connector is recessed:

Delphi catalog result if searching for 2005 XJ8 this pump seems to match what's in the service catalog-- elbow connector and wire harness.


My assumption is that the service manual pictures were not updated. But is there a chance 2007 XJ8 can be using the older style pump with the elbow and wire harness?

 

The reader will tell you the fuel presser, it should be about 55 lbs

 

Before replacing any parts, there needs to be a correct diagnosis path to confirm what's wrong.

First, what is the battery voltage across the terminals with the ignition in the OFF position when checked with a voltmeter? There should be a minimum of 12.6 volts present or the battery must be charged for six hours at 2 to 5 amps and retested. If the voltmeter still indicates less than 12.6 volts, the battery must be replaced.

In addition to testing the battery voltage, what DTCs are stored in the system triggering the MIL? Post them here.

The fuel pressure can be easily checked using a smart phone connected to the PCM via the OBD port with a Bluetooth interface and the Torque app. Fuel pressure when the ignition is turned on prior to engaging the starter should be around 3 bar.

 

Hey JP,
Sorry you're having troubles, but must say that you're making smart decisions so far...
In my case ('07 XJR), "fuel pump" issues (driveability problems plus CEL showing code for intermittent low fuel rail pressure) turned out to be a dirty fuel filter. This was shortly after I bought the car - four years ago - at 82K miles. The filter had never been changed (though car always serviced by PO at a jag dealer)
IRRC, $20 filter is underneath car, under a plastic panel. Takes about 10 minutes to change...
Hope this helps!
PS:
- Get a scanner, as Wing et al suggest. Easy to use, and it will pay for itself immediately (I use an NT501 Foxwell; about $200? on Amazon)
- Battery condition super critical on these cars, as NBcat explains. A bad battery may start your car just fine, but will create many, many problems. Exide Sprinter L5/49/H8 (OE lead calcium type) at Home Depot (of all places) works perfectly; 3 yr full warranty, only ~ $120
- The X350 ('04 - early '06) models had some fuel pump issues. Believe the later X356/X358 cars are less susceptible

 

Pick up one of these fuel pressure gauges from Amazon. Actually, I never had the need to use this fuel pressure gauge on my 2005 Jaguar XJ8L, but I did use the pressure gauge on my father's 1995 Oldsmobile 88 Royale about three years ago. The kit comes with a wide assortment of fittings so the odds are high that it will work on your Jaguar.

As for the code reader, the Foxwell NT510 would be all you'll ever need.

If the fuel pressure is within specs, then the problem would not be a defective fuel pump.

 

Re your photos of pumps-the black one is for diesel.

 

Had similar problem with my 2004 XJ8. No fuel pressure at the terminal port, not even the presence, just dry. Dealer tried to sell me new pump for $1600. Found that at that time Jaguar was owned by Ford and used in the their vechicles the same pump that Crown Victoria !!! Found one on line, $40 shipped. For more info feel free to call me PERSONAL CONTACT INFORMATION REMOVED.

 

Thanks all.

I've ordered the icarsoft OBD scanner, and will report back.
Will also check the battery voltage.

Last time it had the issue, the check engine light didn't remain on. Did the computer store the trouble codes or do I need to first try to replicate the issue?

 

JaguarPwned,

The Reader comes with a USB cable to enable updating online. Do not update the software. Updating gains nothing for our X350's and in fact loses some of the OBD functionality!

 

There could be possible three issues,
- Fuel vapor prohibits the car from starting: the fuel pump is electrical ... turn on the ignition without starting the car and listen/check if you hear the pump working. If not pump needs to be replaced.
- Fuel pump is working but not building up enough fuel pressure: before starting the car turn on the ignition without starting the car and wait 5-10 sec before starting the car. That way the pump can build up enough fuel pressure eliminating the fuel vapor in the fuel line.
- The Air Filter, the Mass Air Flow sensor MAF and the Idle Air Control valve IAC valve can be contaminated over the years. They are easy to find. Start with the air filter and check if the filter is clean. If not replace with a good quality one. Immediately after the air filter housing you find the Mass Air Flow sensor MAF. Disconnect the electrical connector and take it out, usual two screws. Don't touch the inside of the sensor. Use CRC MAF Cleaner and spray the inside thoroughly and let it dry on a piece of paper outside in the air. Don't use a rag of paper to clean the inside after spraying. When dry put it back in place. Now we go to the IAC valve. Follow the black plastic air hose to the throttle body/intake manifold. At the entrance you will find the IAC valve bolted onto the intake manifold. Disconnect the connector and and take it out. Use CRC Throttle Body and Air Intake Cleaner. Don't use the MAF cleaner. Each has its own product. Make sure you don't drop the gasket between the valve and manifold. Spray the inside thoroughly. If necessary use an old tooth bros and scrub it clean.
- While you are at the intake manifold you can go a step further. Take the air intake hose off the Trotlle body. Inside the throttle body you will see a butterfly valve that regulates the amount of air coming in the intake manifold based on the position of the throttle pedal. The edge of that valve can be contaminated and therefore not closing properly when necessary when engine is on idle. Spray some Throttle Body and Air Intake Cleaner on a rag or blue paper and clean the black contamination from the edge of the valve. Use eventually the tooth bros. When completely clean assemble everything back together. Now you cleaned the air intake system as good as possible.

A thing that most of the time is overlooked is the PCV valve Positive Crankcase Ventilation valve. That valve regulates the oil vapors in the bottom = crankcase of the engine and guide those vapors back into the intake manifold to reburn during combustion. Most of the time that valve has never been replaced and get clogged overtime. Easy to find. Follow an air hose from the intake manifold that goes down all the way to the bottom of the engine. In this case the PCV valve sits at the top of the engine passenger side bolted onto the engine and has a round flat top. Can't miss. Only buy OEM PCV valve. Not that expensive I believe approx $70.00 and ease to replace. Just loose up the clamps of the hose attached to it, unbolt it and replace.

I did the all of the above on my 2004 XJ8 X350. Car has 206k miles and running like a dream.

Keep me updated how it goes. If you have other questions let me know. I'm an Automotive Technical Instructor with 35+ years in the Automotive.