Fuel pumps
 

OK sorry for opening an old post. I have had a mechanic replace the both pump motors but not the bodies as per this post. As he suspected they had failed. He is now got pressure at the rail. But the engine is now getting flooded with fuel. He thinks the check valves might be stuck open. Is this likely? He saying the only possible solution now is replacing the whole pumps with secondhand pumps. Any thoughts on this

Martyn,

Give us details of your car, year, mileage etc and the Forum will be better able to comment.
Also some history as to what situation/running problems lead to the replacement of the fuel pumps is usually very helpful

Hi Paddyx350
I think you have been helping me elsewhere with this. My original post is here
https://www.jaguarforum.com/showthread.php?t=113337

Anyway my car is an xjr x350 2003 approximately 130000miles. Symptoms were lack of power and feeling held back. This evolved into revs dropping and then refusing to start. After leaving it a while you could just manage to get it home. Normally it wouldnt throw any codes. I have already changed fuel filter and fuel pressure sensor to resolve a previous over fueling problem. After trying isolate the problem I to took it to a garage specialist in JLR. He was struggling to diagnose as the issue was sporadic. Although in my opinion the low performance was always there. Eventually it broke down on him. He said the pumps had failed and hence we went ahead and replaced the two pump motors.

Martyn

Hi Martyn,

The check valves always allow fuel to flow from the pumps to the fuel rail. When a check valve fails, it then allows fuel to also flow backward, from the fuel rail into the fuel tank. I don't think there is a check valve failure mode that would contribute to engine flooding.

Is the fuel pressure too high now? Is DTC P0193 flagged? How is the mechanic monitoring fuel pressure? Via the Schrader valve on the fuel rail or via OBDII?

Cheers,

Don

Hi Paddyx350
I think you have been helping me with this elsewhere. My original post

https://www.jaguarforum.com/showthread.php?t=113337

Anyway initially my x350 xjr 2003 130000 mile was lacking performance and holding back. It evolved into loosing revs then cutting out. It would then struggle to start unless left for while. It wouldn't normally throw a code. Took it to a garage specialist in jlr. The mechanic was struggling to diagnose because the problem was sporadic. Although to me it was always lacking power even if it wasn't stalling. The car broke down on him and said the pumps were nackered. So he replaced the motors as per above post. He now says the engine is flooding with fuel and that the check valves must be stuck open. Thinking about it would this result in fuel leaking back to the tank and loosing pressure?
Any thoughts anyone?

Thats what I was thinking. Isnt there also a pressure relief valve. Could that be stuck closed? Is there just one pressure relief valve?

Hi Paddyx350
I think you have been helping me elsewhere with this. I have tried to repost my original post here. A way my car is an xjr x350 2003. The car first felt like it was lacking power but this was all the time. Then it started to loose revs and cut out. It would fail to start. Normally you could eventually get it to start after a while. I then took to the garage which is specialist in JLR. He was struggling to diagnose because it was running OK. It then broke down on him and he said the pumps had gone. So he changed the pump motors as above.
Previously the car had a new fuel pressure sensor and fuel filter to cure an over fueling problem.

Mechanic has stated fuel pressure was 60 psi. Pressure sensor high fault logged. He didnt confirm if this was with a mechanical gauge reading or obd. Communicating via text as he has gone on holiday.

Just an FYI to some or all of you normally-aspirated 4.2 folks out there. This thread might not apply to you. See this thread instead. At least some of these cars have a single pump which is located on the passenger side. The internal pump motor is different than the Pierberg unit that is used in the XJR. It is a common pump that is used by a number of manufacturers, and is common to many Fords. There are differences in the types of plugs on some makes so you might have to source a plug and replace the factory one. I installed one of these. The plug is the same as the Jaguar factory plug (at least in my car), so it was a really simple replacement.

the XJR twin pump is either dual lincoln aviator pump motors or a pierburg unit identical in dimensions to the e39 m5 fuel pump

gents,

i am the happy owner of an x100 xkr and am now buying a '04 xjr to go in the stable. it cranks over but does not light off and is presumed to be fuel pump. my bit of research seem to say that this year of xjr has two fuel pumps like my '05 xkr... with 120k on the meter i am thinking it best to replace both fuel pumps (if it does have two) and go from there... this is based on reading a few threads here to the effect of being on "borrowed time" anyway.
my long winded question here is about an aftermarket part number for both fuel pumps ? i am seeing a lot of chinese junk in my searching...
would any of you be so kind as to offer up ? do i need to be buying any additional supplies to do the job ?

many thanks,

max

fuel pump lock ring tool is nice and cheap. if you have the lincoln aviator pumps you need to buy used or two entire assemblies from ford and gut the pumps out

if you have the pierburg you need to buy two of

https://www.fcpeuro.com/products/bmw...g-7-22013-61-0

thank you xalty !
i see the ring tool on ebay.

so it sounds like a simple enough job to take on in the back driveway

kind regards,

max