Hi, I'm new to the forum having just purchased a 2003 XKR (35,000 miles). Test drove OK but seemed to be a bit under powered. Post purchase drive lasted about 3 miles when it seemed to run out of gas; loss of power then stalled. Wouldn't restart. Put in 2.5 gal of gas (perhaps the guage was faulty?), some water absorber and can of octane boost. No luck starting. Towed it home.

Today, checked the OBD II codes, none. Replaced fuel filter (PITA), no change. Checked all fuses (all good) and have 12.5 volts from the battery. Reset inertia switch in case that got set off. Sprayed starter fluid in air filter; it started and idled fine until it ran out of the juice. It stumbled whentrying to give it gas under starter fluid. Not really a surprise. Thinking I'll check the fuel pressure at the rail tomorrow and if low/poor am incl;ined to think it's the fuel pump. I'm not suspecting the throttle body as I beleive that would throw an OBD II code. Would appreciate any thought and suggestions.

Kip

 

Fuel pump very likely.

 

​​​​​​This ^^^^

Did the car sit long before ya got it?

Is there a schrader valve on the rail for a 2003? If so, turn the key to the ON position and take something and poke the valve and see if there is pressure... Even if there is doesn't necessarily mean the pump is pumping 100%, but the pressure should be significant - of there is any. Have a good sized rag or towel handy to sop up the fuel... Careful careful

 

Thanks, guys. The car was driven at least once a week (not far, but driven) prior to me buying it. A small dribble from the schrader valve when depressed and the the key is on. Will be pulling the tank tomorrow to get at the pump. Will let you know.

Kip

 

I found a used fuel pump for a 4.2L XK8. Does the XKR and the XK8 4.2L use the same fuel pump?

 

Doesn't the XKR have 2 fuel pumps?

 

Good find on the used pump! See that the seller has a return policy, unless it's tooooo late already... Thing is, and others my correct me (hopefully) if I'm wrong but with the 2003, 2004 somewhere in there, the 4.2 SC went to a single pump, returnless system and pulse width modulation for fueling. I THINK the 2003 SC is a single VDO pump. And expensive. The double pumps, pumps are pretty inexpensive.

 

And! Importantly...

Some have gone thru the rear deck in coupes... I have a convertible and in 15min cut an access hole on the rear deck. Coupes, if you remove the rear speaker and are able to shift the tank around cuz ya loosened the large retaining plate in the boot, the pump is accessable that way - I believe.

Cutting the back deck seems violent. But so far so good for me. I can access the pump and the pump assembly in 10min. Never going under the car. For me, with 4 cars, accident limiting is important. The less I have to be under anyone of these things the better. But that's just me.

 

Appreciate the tip on going through the deck. Mine is a convertible so will have to look carefully at that but I like the idea of not having to make a special tool to release the gas line above the differential!

Is there anyway to determine if it is a double or single pump before pulling the pump out?

 

If it's a 4.2, then it's a single pump, hand crafted in platinum (at least, you'd think so, given the cost of replacement).

From the 2003 service training guide:

"
ENGINE MANAGEMENT (Cont.)
Fuel Pump
To support the installation of the 4.2-liter engines and continuing the drive for fuel
consumption benefits, a new fuel system including fuel tank, fuel pump, pipes, breather
pipes has been installed.
The XK now benefits from the use of the return-less fuel delivery system very similar to the
X-Type and S-TYPE models.
One major change on supercharged (S/C) variants is the use of only one fuel pump instead
of the usual two as used on all previous S/C models (XJR, XKR and S-TYPE R)...
"

 

The fuel pump part # for the 4.2 SC is different, C2N1147 vs C2N1146 for the NA engine.

 

The fuel pump "assemblies", to my knowledge, are separate part#. The XK8 and XKR have different pop valves. The XKR's pops at a higher pressure. These pop valve come into play when the throttle valve is suddenly closed and the fuel pressure needs to be quickly dropped. Remember, these cars (2003+, 4.2L engines) come with a single pump return-less system, i.e. there is only a supply hose to the rail. That being said, it might be possible to swap the pump part of the assembly, but I have not seen any post about that procedure specifically.

PS: FWIW, fuel pressure is available as an OBDII PID. Should read 55psi at all times.

 

Thanks Mike 😊

 

So appreciative, guys. Turns out the used one was for the NA not SC so ordered a new one.....$870. But can't say I wasn't warned .

Jay - any special instructions/thoughts/pictures on accessing the pump through the convertible top well?

Kip

 

With addition poking around today, I see what looks like a silver ~ 2" dia fuel pressure regulator on the inlet line for the left fuel rail. Could this go bad? Any concerns if I took it out of the system to test start?

 

It is a "dampener" I believe. They are not generally reported as problematic.

With such a high cost for the pump, it would be best to double check the pump part is actually bad. If you check the electrical guide on jagrepair.com, you can see the entire system. It no longer is a basically always on pump with a regulator to take care of the pressure. The pump is driven by a control module that issues variable power by PWM to control the output pressure (the input is the fuel pressure sensor at the end of the rail). I assume there are a number of fuses and relays to check. Might be worth trying to power the pump directly to confirm it is dead.

Once you have visibility into the tank, the condition on the inside may tell you a lot. Aging cars with stagnant fuel develop rust, fuel separates and sticky sap-like deposits gunk everything up. No sense in replacing the pump if the tank is a nightmare. FWIW, once the pump is out, try and soak it in injector cleaner for a while. Try and rotate it by hand. Some even power the pump at 24V for a quick jolt to try and unfreeze it.

If you feel like it, take pictures. The community here has not been able to find a replacement pump yet, so everyone has to buy the entire a$$embly.

Best of luck, keep us posted.

 

I'll check out the diagrams for sure. I also cut the fuel line before the "dampener" and turned the key. I got 1/2 cup from the initial "pulse" and then a steady flow and about 2 cups of fuel when I turned it over a few times. Certainly wasn't 55 psi but not sure exactly what kind of flow I'm looking for.

 

870$ Damn Bro's living large 😊

Actually, I've been trying to plan ahead for my next go around (which is never far enough off) to find a suitable pulse width modulation pump to replace the OE VDO pump ONLY. The rest is pretty much a hunk of plastic. As long as the/a pump can be placed and secured in that basket I can't see why another option could work - reusing the old basket. Might save the next guy $700.... Anywho,,,,

I want to be careful because I know some don't approve of the cutting approach. So, this is just me....

I know that some have reported using a circular/barrel saw bit,,, with a big 90degree drill rented from a Lowes or Home Depot. Then, carefully cut the hole.

Me, I can be a bit of a NUTT job, so I took one of those smaller cutoff wheels, fine blade, and chose my path. There are about 5 vents at the very back of the back shelf and what I did was plan to make my cuts begin and end into these oblong ovals which then (post cut) act a little like a bendable hinge of sorts - you'll see. From there it's easy to just flip the section of steel up (it's soft grade sheet), handle your business with the assembly, and then press it back (basically) in the exact place it sits/sat. Then, I used some heavy duty aluminum tape to seal it up.

In the tank, the entire assembly is about a 6th of a turn to twist out of the base of the tank. BE CAREFUL OF THE ARM OF THE FUEL LEVEL SENDER!!! Got to be a bit of a contortionist to get the hands and a forearm down in there. Then (maybe first) find the line that feeds the fuel line,,, follow it with your hand down to the bottom of the tank, then it's a simple find the little button on the end of the line, push, press and lightly pull. Might take a couple of attempts.

No matter what, remove the large tank securing plate in the boot/trunk, maybe 5-7 large-er bolts.... Get a GOOD eyeball of the position of the top of the tank and pump assembly in relation to that back deck before cutting anything. Careful careful.

You got this

 

Update on the fuel delivery issue. It was indeed the fuel pump. New one purchased (that leaves a mark) and installed. Car starts and runs smoothly. I decided to remove the tank since I had time due to the 4 day delivery on the pump. Watched a few YouTube videos an getting that @#$% gas line off, made the "special" tool out of 1/2" PVC pipe and it didn't work. Went and bought the Ford quick connect release kit from Advanced Auto for $10 and had it off in 5 minutes! This is the same tool Jag will sell you for $16. Yes, you have to get your hand up in there to install it, but there is room. Comes off like "butta!" The rest of the removal is easy but I recommend putting some tape on the tank seam or cardboard on the wiring harness before moving the tank so you don't skin the wires.

Tank was clean, new pump is in. Test drive was fine until I got into it a bit. Then it started to sputter at high revs. Ended up showing a check engine light. Light went off after letting it sit a few minutes but the OBDII showed two codes: P0191 and P1000. 0191 indicates a fuel pressure regulator and 1000 is some crazy reset procedure for the CPU. I'll get in to these next week but any comments on these two codes would be appreciated. Think I'll do the CPU reset first and see if the pressure sensor codes is related to that rather than an mechanical sensor.

Kip

 

P1000 just means the emission system self check is not complete. If you disconnect the battery that will show at startup. When sufficient drive cycles are completed it will be P1111.