On my way back from Vegas a couple weeks back, my car just stopped running. It wasn't a sudden stop, it started by simply not accelerating when I stepped on the gas pedal. There was no response at all if I pressed on it. Sometimes accelerating very slightly. It eventually came to a stop, but always had enough time to pull over on the shoulder. At first I though it was overheating, but the engine temp was normal. Plus I live in Indio, significantly hotter than Vegas and never had problems.

I pulled over a total of 9 times. Each time waiting 30min or so before starting it again. Because of how the car stopped, it felt like it was the fuel pump. It felt there was no gas going to the car. Do fuel pumps over heat? Why is it after a short wait, the car was fine again for a few more miles? If heat's an issue, why do I have no problems now and there's 115F+ weather? Or maybe it's something else?

 

The 88-90 cars use an external fuel pump, mounted on the rear suspension subframe. During prolonged driving in hot climates, the fuel pump will cavitate and cause a loss of fuel pressure and volume, which causes the symptoms you describe. There is a factory service bulletin from 1990 explaining this problem, and directing the installation of a second fuel pump with a rather complicated arrangement of hoses to connect both pumps in parallel.

I don't know how often this kit was actually used, and I have only seen one such setup during 20 years of servicing XJ40's. Replacing your single pump with a new Bosch fuel pump as fitted by the factory will cure the problem. Of course there is always the possibility that some other fault is causing similar symptoms, and testing is the only way to confirm yours. As far as likelyhood goes, you have probably identified the culprit. It's a relatively common problem.

 

i have the same problem on a XJ6 1993 !
any clue ?

 

That's probably just a pump fault on a 1993, although the in-tank design decreased the effect of hot weather running. The best way to determine the cause is to drive the car with a fuel pressure gauge connected to the fuel rail. You can't buy anything off the shelf though, you'll have to get at least a 40PSI pressure gauge and make your own adapters.

 

thanks for the quick replay.
i will do it !
and post back.

 

You´re not alone. I had to replace the fuel pump in my 1993 XJ40 just last month.
A Carter pump was about $125 but removing the fuel tank to put it in was costly.


panza
2002 S type 4.0 (nothing wrong yet)
1993 XJ40 (back in the shop... tailight fuse problems)
1993 XJ40 (getting a head gasket and timing chain tensioner a day after I bought it and nothing seemed wrong)
1992 XJ40 Sovereign green...(no problems and proud of it)
1985 XJ6 Series III (blew a lower hose last week...nothing wrong now and it´s available for an adoption fee to a good home)

 

does not make sense (the fact that when turned off for 30 min works again) but impossible to be the fuel filter, no ?
going back to the fuel pump problem,
im trying to imagine a fit for the fuel pressure gauge, im getting this one: http://shop.advanceautoparts.com/web...GRPBODYAMS____ , but how do i get the fitting for a xj40 1993 ?
any clues ?

 

dumb question ....

could installing a secondary fuel pump instead of replacing the failing one (by removing the Fuel tank) be good option ?
please advise.

 

I will replace the pump as my first thoughts were. Since it lays outside the tank, and not inside, I can replace it myself. A new pump goes for like 80 bucks on eBay, so it a trial and error I can afford.

 

I wouldn't use anything other than a Bosch pump if you're keeping the car. I recently replaced a customer's pump for identical symptoms which was an aftermarket installed by the the previous owner about 1 1/2 years prior. You gets what you pays for.

 

that said, i would like to go for the BOSCH pump, so far as i know, the whole fuel pump assembly for a Jaguar 1993 XJ6, is the JLM21258, but what is the exactly model of the BOSCH PUMP alone ?

 

Different story for the '93, you can go to most auto parts stores and get an Airtex pump.
I think it's E8973, but Advance or similar will have it listed by application. That gets you a pump identical to the factory Walbro unit...the trick is, you have to open up the pump module to replace just the pump. It's a bit of a fiddley job, but the factory pump (which is the complete new module with the pump installed) is like $500.

If the link lead (wiring harness to the pump ) has burned connections at the plug on the top end, you will have to buy the complete module from Jag to get that item. Otherwise you will have to repair the connections, not easy.

 

The Carter pump for the 1993 XJ40 has Walbro´s insignia stamped into the body of the pump. I assume that it was actually made by Walbro.

 

Hi Panza,

I think you're saying that you bought a pump in a Carter box and it was made by Walbro? Same as the Airtex, it's the OE Walbro pump. Usually about $125-140 will but one. The Airtex comes with both filter screens, I'd guess the Carter did too.

 

hi there. I checked the voltage and connections to the fuel pump, and all looks fine, also fuel pump relay seems to be perfect.
car behaves perfectly on idle all the time, it is when i hit the gas (even in parked or neutral) ithat it losses power, even goes below idle speed until i ease the gas pedal, and then goes back to idle perfectly. im receiving the fuel pressure gauge hopefully by friday, and from then to confirm that: when problem occurs that it is because i do not have pressure on the fuel rail.
im trying to be completely sure it is the fuel pump before taking the fuel tank out, (that work was made by the mechanic like a year ago, and new fuel pump assembly was installed, costed me $800 the assembly and $600 the labor, so hopefully it is not the pump...), will keep posting. what are probability there is a problem in the MAF ?

 

Did you get your problem sorted?

Just an idea...my Mum has also got an XJ40. Hers kept cutting out, and it turned out to be the fuel pump relay.

Could be worth checking...good luck!!