" I also noticed that my return line in tank on has a dribble of fuel coming out. I blew out that line and I am going to do it again. THE LAST TIME i DID IT i APPLIED PRESSURIZED AIR TO THE RETURN LINE AND FUEL WAS BLOWING OUT OF THE SUPPLY LINE AT THE RAIL. OUT OF THE EQUATION WAS THE FPR. Could it be that since it is doing the same thing with two pumps that the problem is elsewhere? Maybe the FPR? but then if it is staying open I should see fuel at the return in the tank."


I'm a little confused by this....
How was the FPR out of the equation?
Where are you hooking the Pressure gauge?

Normally the car needs around 32-33 PSI to run correctly. It does drop under load somewhat, but is controlled by the Fuel Pressure regulator.
The fuel will return to the tank in a sort of a dribble, not a really strong flow (as it's South of the FPR, and not under pressure as much as gravity)
However you may want to check both tanks, to make sure it's returning only to the correct tank.. (not related to your running problem, though)

The best place to connect a pressure gauge is at the Cold Start Injector....

If Gary (Jagbits) has the OEM fuel pump for that price, it's a really good deal, jump on it..
Some of the aftermarkets supply too high a pressure to the rail, and that will cause as many problems as not enough..

Good Luck with your project...

David
Everyday XJ

 

@David: "I'm a little confused by this...."
a)I disconnected the return line from the FPR and disconnected the supply line at the fuel rail. I then applied air pressure to the return line. The fuel rail and the FPR are no longer in play. Applying air to the return line, air is being pushed thru the return line to the passenger side tank and back thru the supply line which I have placed in glass bottle.
With the air at the return line and the supply line disconnected from the rail, the air pressure is not going to the fuel rail or FPR. this was just to make sure that the return line was not clogged.
b)After reconnecting the supply and return lines, my fuel pressure gauge is connected to the cold start valve nipple on the fuel rail. Fuel pressure starts at 40 psi then drops to 20 psi and the engine stalls out.
c)Left side tank is leaking so I have the switch set to the right side tank. No fuel is returning to the left side tank. It just dribbles to the right side tank.
d) I removed the fuel rail and injectors as a complete unit and checked to see that all of the injectors were spraying properly when the pressure was at 40 psi. From what I can tell they were putting out a nice wide spray. Of course as the fuel pressure drops that fuel spray pattern will change.
Hope this explanation clears up this for you.

 

Perfect... Thanks for catching me up.......

Sounds like you have done everything correctly...
I'd think it points to a faulty fuel pump..
I think you mentioned trying another... Any chance it may be faulty as well?
I've seen them idle with 36psi all day, but as soon as it was under load (driven), the fuel pressure drop seriously low.. I put a fuel pressure gauge on a 6' hose so I could watch it going down the road....

Best advice I could give at this point is to be sure to get an original fuel pump...
Too many problems with the aftermarkets.... Generally I'd prefer a known good used original to a new aftermarket....
But like I said before, if JagBits are OEM, that's a great deal...

This girl has one on Ebay for $130... Its a new OEM Bosch pump...
I've bought a few things from her.. She's a good seller.... She inherited a shop with Euro parts in it, just clearing it out. (NO AFFILIATION)
She has it at $130, but with a best offer... She's had it a while, so I bet you could get it for less....
Bosch Electric Fuel Pump 0580464008 Jaguar XJ6 XJ12 Vanden Plas XJS | eBay

Cheers
David
EverydayXJ.com

 

To the Bosch and Fuel experts on this forum. What is the difference between the bosch fuel pumps 0580464014 and 0580464008. Is one # superseding the other or is there a difference in fuel pressure? The physical dimensions look the same. HELP

 

If I am understanding these charts correctly.....

http://www.bosch.com.au/car_parts/en...l_Pump_WEB.pdf


.....both the 0580 464 014 and the 0580 464 008 are replaced by the 0580 464 070

This suggests to me that the differences between the two were not significant....but I can't tell you exactly what those differences are.



Cheers
DD

 

A couple of ideas: but, caveat, I have yet to get my little B&S to start!!!


1. Pressure test the FPR. One to see if the diaphragm is bust. Two or three PS gauges needed. 1. Apply 60 pounds or so and measure at the fuel pump inlet. 2. A guage at the injector rail side. Drops and holds around 35 - 40? 3. Attach a temporary line to the return spigot and to a receptacle. Any thing of consequence coming out?


2. Measure PSI's at the pump outlet. Can it sustain at least 60 psi for a period of time?


3. Plumb a known good pump at the rail and from a small vessel containing fuel


You oughta get some data from which to draw conclusions


Good Luck.


Carl

 

FYI I installed Bosch part#69414 from this page in July and all is well.

 

Round 1 (yesterday)
So I bit the bullet and acquired a genuine Bosch fuel pump locally. Before installing the new pump I flushed out the system. With the new pump installed, I applied voltage directly to the pump and bled the air out of the system by loosening the nut at the FPR connection to the fuel rail. Fuel pressure @ 42 psi. I have left the gauge hooked up to the cold start injector nipple and had the car running for about an hour. The fuel pressure stayed at around 32 to 35 psi. If I accelerate the engine fuel pressure will increase a few psi which I believe is normal and telling me that the FPR is working as it should.
Round 2 (today)
Went out to start the car and the fuel pressure (before cranking the engine) is at 0 psi. This is telling me that the system did not hold the pressure overnight. Cranked the engine forever, I can hear the pump humming, but the fuel pressure will not build up to the required psi. All of the voltage specs at the diode pac, the green/white wire to the pump and the connections at the AFM as as they should be according to the "book of Doug in the bible of Jaguars". However if I put the car in drive, turn the key to the 'on' position and manually move the flap at the AFM the pressure builds up, and the car would start.
My questions now is:
a) Shouldn't the fuel system maintain the correct fuel pressure overnight? and if so, what is causing it to bleed down to 0 psi?
b)Why when cranking, the fuel pump works but it does not pressure up the system?
Why when I manually open the flap, past the point when I hear the fuel pump relay click, does the system pressurize.
If I simulate the slight movement of the flap that would occur during cranking, I hear the relay turning the pump 'on' and it should pressurize the system, but it does not. However if I move the flap about half way the system pressurizes and the car will start. STRANGE BUT TRUE.
c) is there an adjustment in the AFM for this problem?
If not some ideas are welcome.
Finally is there a one way valve I can install in the fuel supply system, to hold that pressure overnight when the car is not running?
and finally, finally, What is the purpose of unit near the filter? It has the line from the pump going to it, a line going to the filter and what seems to be a return line on the top. It looks serviceable. There seems to be a threaded part on the top. I will try to post a pic of this unit, if it is not clear to anyone what I am talking about.

 

So far so good !



There IS a one way valve in the system. It screws into that odd brass fitting (air bleed assembly) near the fuel pump

BUT....

Even without a valve, or with a faulty valve, the fuel pump should re-pressurize the fuel lines and fuel rail very fast. Like...3 seconds or so.




You'd think.

But, mine never did. A few hours, perhaps. I guess the one-way valve isn't immune from bleeding down


Use a voltmeter to check voltage at the pump A) key on, AFM flap open and B) with key turned to 'start'.

I'm guessing the pump isn't getting full voltage in 'start' mode....due to a problem with the diode pack or immediately before the diode pack

More later

Cheers
DD

 

I had a similar problem a few years ago on my Jeep, replaced the non return valve with a genuine one,improved overnight pressure but not totally.
A local mechanic put me onto the fuel check valve below,never had a problem since(4 years).

BMA Auto Parts | Bumper to Bumper since 1978 | Oem auto parts, vw parts, sachs boge, mercedes benz parts, honda auto parts, saab parts
16149068988 check valve kit...$7
patrick@bmaparts.com

 

A big thank you to all who contributed to helping me resolve the fuel supply issue on my Series III. A special thank you to Doug, who was 'on the money' with his input. Thank you, thank you.
Now on to another issue. My fuel gauge is not working. As I stated in my posts, the driver side tank is leaking and I will be removing it in due course to see whether it could be saved or whether I will have to purchase one.
Working with the right side tank, I removed the tail lamp , to remove the sender assembly. I have no power on the green wire (+) at the sender. Fuse 4 is good. Does this circuit go thru the gauge and then to the sender? Or does it go to the sender, then back to the gauge? I want to resolve the electrical issue first before I remove the sender assembly. Is the circuit to the right side tank independent of the left side tank?

 

You won't see "+" voltage at the sending unit wire. It's a *ground* wire. The sending unit provides the dashboard gauge with a variable ground signal.

The dashboard gauge itself is supplied with the "+" voltage

Right-left independant, yes. Two sending units.

More later Off to work

Cheers
DD

 

1)Thank you. I grounded the green wire and the gauge moves. I removed the sender units and they are no good. I have to purchase two of them.
2) the fuel check valve in the trunk is allowing fuel to bleed back to the tank. I am in the process of locating an inline check valve to see if that would help.
3)The idle RPM is too high. It is staying at around 1500 rpm. I am working on this to see if I find the cause. So far, no vacuum leaks, throttle valve is set correctly @ 2mm, and the air valve was removed and cleaned, presently, the air adjusting screw is all the way in. I would think that if everything else was OK, turning the adjustable valve screw all the way in would allow the RPM to drop, so maybe there is an air leak somewhere in the system. i have checked everything from the AFM to the throttle body but it seems I am missing something.
4) I got three of the six window switches working. The spring loaded plastic pins were worn. I had one good pin and I used that as a template to build up the worn pins with epoxy. I will complete the others in the next couple of days.