Max-
If you want to work on complex problems on these cars successfully, you really need to get the service information. I suggest finding yourself an old $50 used PC on Craigslist to run JTIS on, or alternatively buy a subscription to Jaguar Topix: TOPIx - TOPIx

Your code indicates a problem with the pressure sensor, or less likely it's connector, wires or ECM. JTIS has some tests you can try to isolate whether there are shorts or opens in the wiring or ECM.

 

I just checked my car. I installed a relay that connects 12vdc directly to the fuel pump when the relay is activated (long story). With 12vdc directly to the fuel pump I have 70 PSI at the fuel rail. When I start the car and it's idling I have 50 to 55 PSI at the fuel rail.

If you're only getting 15 PSI at the rail is sounds like you have a bad pump. Even if you had a partial clog, the pressure would gradually rise until the pressure behind the clog was equal to the pressure in front of the clog (assuming the engine isn't running).

 

Max- After re-reading your post, I think Rev. Sam is right.

 

Max,
Is your Fuel Tank Pressure Sensor plug also unused (the only reson for calling it that is due to the colouring of wires being identical to that of the Fuel Tank Pressure Sensor as published in JTIS)?

 

Problem Diagnosed and SOLVED!!!!

WhiteXKR: You are right, and I will explore the cost of TOPIx.

Rev Sam: Your videos inspire me, and "You are correct SIR!" it WAS the fuel pump (see below)

XKR: I saw a picture online somewhere of a totally melted down fuel pump
(it may have been on Gus Glikas website) that apparently was actually still running. I wonder what mine is going to look like when I get it out of the tank? Secondly, yes, my fuel pump pressure sensor harness IS hooked up to a connector on top of the fuel tank - next to the main pump connector.

Here's what I did, I thought real hard about the clues I had collected and decided that there was no way I was having timing chain problems - 'cause it did start for a moment the other day - idling smooth as silk for a moment AND the fact that it was cranking normally when I tried to start her up... It just couldn't be a timing issue. Also, Reverend, the fuel pressure being so low was another certain clue also.

I'll try starting her up on another pump!

Not having a stand alone, in-line fuel pump that could develop 30-50psi on hand to test the "bad pump" theory, I decided to construct an "IVP-AP/FP" or an Infinitely Variable Pressure, Air-Powered Fuel Pump! A few hours in my man cave of a shop would certainly be better than running out and blowing "high-dough" on an overpriced fuel pump - just to find out that it may have been something else.

I found an old acetone can that was constructed fairly sturdy and had a good sealing cap. So I rummaged through a box of brass fittings I have been collecting since I was 15 years old and found just what I needed. I brazed the two bungs I found (one for air from my compressor and the other as a fuel nipple) to the upper and lower sides of the can. Tested it to 50psi and deemed it good to go. - I added an inline filter too. Just in case.

I had a can of injector cleaner that a neighbor who works for GM gave me a year ago. I poured that stuff into my home-made "IVP-AP/FP," screwed the cap down tight, brought the air pressure up to 35psi, noted that the fuel pressure gauge up front attached to the schrader valve was also showing 35psi, and fired her up!

VaRoom! She started instantly and settled down to a nice smooth idle for about 20 minutes as the cleaner was forced down her throat. My wife stood by with a fire extinguisher (not trusting me) but within a few minutes of smooth running she giggled and ran inside to get the camera to document my "Caractacus Potts - like" creation... Yes I know I could have gone out and purchased an OTC 7448 Fuel Injector Cleaner for about 150 bucks that would have done the same thing and looked waaaay nicer. But hey, there ARE times when you have to let the wife think you are a genius right? And besides, in the good words of the Rev Sam, I'm cheap!

NOW: Please advise me on a GOOD DEAL on a new fuel pump guys! My Gawd they are expensive!

This forum Rocks! And I salute you all!

Thanks,

-Max

 

Wow!

 

Now that's good 'ol American ingenuity right there!

I'm glad you found your problem, but sorry to hear it's the high-dollar pump.

Mike

 

LOL! That's awesome! I can't believe the can handled 50 PSI without bursting.

The cheapest you'll find a fuel pump is about $400. I looked and looked for cheaper ones, but they aren't made. I found a couple of websites that claimed to sell a 2003 fuel pump for about $100, but when I dug into the details that same fuel pump was supposed to fit any XK8 from 97 through 2003, so I knew it wasn't the right one.

Oh yeah... if you don't have to return the old pump as a core item when you get your new one, I'll gladly buy it from you if the price is right. I'd like to disassemble it, see if there's a check-valve in it, and if so, I'll try to put it in my fuel pump. I believe that I also need a fuel pump, but my problem is completely different than yours.

 

Yeah Sam, I hear ya about the can possibly blowing! I stood back a few feet and had it on the floor when I put 50psi into it - just in case. The bottom did POP! out at about 48 psi (from inverted to bulging) but I pushed it back and decided I wasn't going to go over 35-40psi anyway. I wasn't real good at braising those heavier steel bungs to that thin wall steel can and had to braise up a few holes I blew in it along the way. In a water test, it leaked a tiny bit around a couple of the welds, so I slathered 5 minute epoxy on the suspect parts and placed a solid layer of that thin aluminum foil tape on to whole can.

I never ran more than an indicated 35psi when I had fuel in it, and you can see the fire extinguisher in the picture. So yes, I was a bit concerned. But I bet most of us have risked way more than that little deal when we were younger - can you say "Estes rocket engines and black cats make good booms?!!"

I have an email into Nalley Jaguar - but haven't heard back yet - Isn't that the place that you were priced $435 bucks? I'm gonna call them this morning.

Sure, I will let you know about the old pump as soon as I get the new one into the tank. I wonder if someone had put a different pump (with no check valve) into YOUR tank - before you bought the car?

By the way, the BMW guys that might look down at you having to crank your Jag a moment before it starts can blow me! I get more envious looks and thumbs up in my British racing green coupe in ONE DAY than they have probably received EVER! They just don't get it.

BMW and Mercedes are belly-button cars - every one has one... Meh.

Anyone that has a line on a deal for a 2003 XJR pump, please let me know.

 

When it first happened, a guy who has started working on my XKR came and looked it over and during the few seconds that the car would run there was a noticeable rattle in the supercharger. After having the car towed to his place, he pulled the supercharger and found broken "blades" which probably didn't have anything to do with inability to keep running, but which I went ahead and had fixed. One of two fuel pumps was inoperable, but we got both (rebuilt ones) for about $300 so we went ahead and replaced both. Finally, airflow meter was replaced after check engine light came on after first two repairs. It is now running fine.

 

Pump works, 7-9 PSI at the fuel rail.
Applied an air line before the filter, with a pressure gauge attached to fuel rail and achieved 40 PSI (no blocks).

 

XKR, That sounds like the same symptoms my car just exhibited.

My car is still not running (I'm waiting for parts) but it did run perfectly when I used air pressure to force the fuel down the line.

For me, I HOPE the the problem is a dead pump - I'm putting my financial eggs in that basket!

Luck be with you.
-Max

 

Do you have any pictures of the check valve?

 

Member "XKR," the check valve problem is a long-going problem with "Reverend Sam's" car. My car did not have excessively long cranking at start-up caused by a not-fuctioning check valve.

I am surprised it didn't have that leak-down problem though.... When I pulled my tank out and removed the fuel module, I noted that the check valve had a broken plastic fastener on one side of it! It was probably only a matter of time before the other fastener broke off and the valve fell apart - loosing the O-ring, spring and the rubber stopper down into the tank somewhere. As it was, I could not find the little piece of broken plastic fastener that had cracked and dropped off the valve anywhere I looked inside the tank. Of course, it is VERY small and could be hiding behind one of the metal baffles in the tank.

When I carefully took the top of the module off I found a fair amount of little slivers of bright metal hanging out in the nooks and crannies of the swirl pot. I removed them with a strong magnet and some Q-tips. I'm guessing that those slivers were recently shed from the gears in the pump...? Remember, like your pump, mine was running and sounded fine - it just developed only about 10psi of pressure at the schrader valve up front at the engine (and at the fuel line before the filter.) Over-all the tank was spotless and the swirl pot and sock filter were fairly clean for the 80k miles my car has on it. This, perhaps, a testament to the former owner using quality fuel from a reputable gas station???

Don't bother trying to find a exact replacement pump (in the States anyhow) The pump and entire module is made by VDO and a phone call to a tech support person at the only USA company handling the importation of VDO products resulted in the disappointing news that VDO doesn't list those pumps as available for individual sale. I was told that they make a lot of products that are ONLY sold to the OEM clients - and this 2003 XJR Pump was one of them - "Good Luck!" he said to me....

I DID however find a number on the top cover of the swirl pot that roughly crossed with other Ford Motor Company pumps - for the super HP Mustangs and the 2005 Ford GT super cars. In my research I have certainly had a crash course in how "return-less high pressure fuel systems" work!

Once I get my car running again with the salvage-yard pump assembly I purchased from Jaguar Heaven in Stockton, CA (it arrived at my home today.) I am going to buy one of the Ford pumps (new cost $160-$250) and retro-fit it into my Jaguar pump module assembly, fix the check valve fasteners and have it waiting on the shelf for potential use at a later date.

 

 

Yes, member "XKR" your pump looks pretty much exactly like mine did - except the plastic clip on the check valve on the outside was broken and the clip on the inside was barely intact. In fact, a couple of days ago when I was checking on a couple of things on the original fuel pump assembly for member "Reverand Sam" the other clip cracked when I just picked at it a little bit.
My valve had not yet come apart and tossed an O-ring and the spring & tip seal down into the tank as your did. But - it's is easy to imagine that if my pump had not shelled itself when it did, my valve would have come apart (like yours did) very soon.

My car is now running great (with the salvaged pump assembly from Jaguar Heaven in Stockton, CA.)

By the way I like your 5 gallon bucket fuel tank in your trunk... You know, that would be MUCH easier to change out than the stock fuel tank - perhaps you could put the lid on it and use bungee cords to secure it into place and, easy as pie - your done!

Well, maybe not... Your range would suffer a bit.

Cheers!

 

Plastic everything. They sell better made squirt guns at Walmart!

BTW, empty propane propane cylinders in the small disposable sizes are sturdy and free at the recycle bin. make sure they are purged properly if welding

The matching threaded fittings can be found in the bbq parts replacement section.

 

The other clip was also cracked in the middle and fell apart on re-assembly.

 

I found this information I hope it helps.

What does this mean?
OBD Code P0191refers to
The Fuel Rail Pressure (FRP) sensor is a diaphragm strain gauge device in which resistance changes with pressure. The electrical resistance of a strain gauge increases as pressure increases, and the resistance decreases as the pressure decreases. The varying resistance affects the voltage drop across the sensor terminals and provides electrical signal to the Powertrain Control Module (PCM) corresponding to pressure. Strain gauge type sensors are consider passive sensors. A passive sensor is connected to a voltage divider network so that varying the resistance of the passive sensor causes a variation in total current flow. Voltage that is dropped across a fixed resistor in series with the sensor resistor determines the voltage signal at the PCM. This voltage signal is equal to the reference voltage minus the voltage drop across the fixed resistor. The FRP sensor measures the pressure of the fuel near the fuel injectors. This signal is used by the PCM to adjust the fuel injector pulse width and meter fuel to each combustion cylinder.
Symptoms
Possible sumptoms of OBD code P0191
- Engine Light ON (or Service Engine Soon Warning Light) - Engine will not start
Causes
Possible causes of OBD code P0191
- High fuel pressure - Low fuel pressure - Damaged FRP sensor - Excessive resistance in the circuit - Low or no fuel - Wiring harness connector of the fuel pressure sensor - Fuel Rail Pressure Sensor - Fuel
What does this mean?
OBD Code P0193refers to
The Fuel Rail Pressure (FRP) sensor is a diaphragm strain gauge device in which resistance changes with pressure. The electrical resistance of a strain gauge increases as pressure increases, and the resistance decreases as the pressure decreases. The varying resistance affects the voltage drop across the sensor terminals and provides electrical signal to the Powertrain Control Module (PCM) corresponding to pressure. Strain gauge type sensors are consider passive sensors. A passive sensor is connected to a voltage divider network so that varying the resistance of the passive sensor causes a variation in total current flow. Voltage that is dropped across a fixed resistor in series with the sensor resistor determines the voltage signal at the PCM. This voltage signal is equal to the reference voltage minus the voltage drop across the fixed resistor. The FRP sensor measures the pressure of the fuel near the fuel injectors. This signal is used by the PCM to adjust the fuel injector pulse width and meter fuel to each combustion cylinder.
Symptoms
Possible sumptoms of OBD code P0193
- Engine Light ON (or Service Engine Soon Warning Light) - Engine will not start
Causes
Possible causes of OBD code P0193
- Excessive resistance in the circuit - Low or no fuel - Wiring harness connector of the fuel pressure sensor - Fuel Rail Pressure Sensor - Fuel Pump

This is a link to the 2003 electrical oneline http://jagrepair.com/images/AutoRepa.../jagxk2003.pdf

Look at figure 4.2 For the fuel information

Looks like I was a day late and a dollar short. Sorry!

 

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