1990 XJ40 fuel pump recommendations

After yet another hot weather failure to proceed, but a recovery after an hour cool down, I am going to replace my original 71,000 mile fuel pump. In looking at Rock Auto there are no less than 7 choices of manufacturers,
Delphi, Brute Power, Spectrum, Airtex, Bosch, Denso, and Carter. I believe Bosch is the OE maker. Prices range from $40 to $84. Anybody have any experience with these? I am leaning toward the OE one by Bosch.

With those choices, I’d go with the Bosch, while the Carter would be my second choice.

if it’s an intank pump, doesn’t matter what brand you buy as they are ALL walbro OEM pumps (rebranded/reboxed) …so buy the cheapest - I guarantee it will have walbro stamped on it. I bought the airtex and yes indeed, it was a walbro, just like my mate’s who bought an overpriced Bosch which was also an identical walbro to the airtex.

Bosch is not the oem BTW, Walbro is.

Thanks, it’s an external pump. I do not know what the average expected life of the original pumps is. Perhaps 70K miles is pushing my luck with it but it performs fine as long as the car is not hot and been run for a few hours in 85F plus temperatures. I even had a fuel cooler fitted in the return line under the back seat floor in an attempt to keep the fuel temperatures down for fuel returning to the tank from the hot engine compartment which was 150F yesterday.

My car uses an external pump as well. I’ve replaced mine twice over the years because the first replacement I bought was not a good one. The second one I got is a Bosch and has performed great.


I replaced the previous Walbro pump with a new one years ago. A few weeks ago I made a fuel flow test by jump wiring the pump relay socket. For a successful test a 2L bottle needs to be filled up in a minute. In my case a 2.63L (orange juice) bottle got filled up in 54 sec. It’s still going strong years after.

What were the symptoms of your pump’s failure? Did they just suddenly stop working or run but not put out sufficient pressures? Or? Mine works fine until the fuel gets hot over a period of driving and then stopping for 10-15 minutes. It then seems to vapor lock and the car will not run until there is a cool down period or 1-2 gallons of cooler gasoline is added to the tank.

Its been many years, so my memory is a bit sketchy, but I believe my pump started to get pretty loud. The replacement I put on, which would now be under the Airtex umbrella, was loud from the moment it was installed. After getting sick of that, I got the Bosch which has probably been on my car 15 years now without issue.

This may be of interest from the archives - see my post #13 in this thread from 2009 -


Yes, I am fully aware of that official Jaguar mod but in looking over the bulletin I find it overly complex. I am hoping for a simpler fix. Thanks for your response.

As I said in that earlier post, " the simpler answer would
seem to be just to replace the original pump with a new one
and drive for another few years with no problem."

Kudt did mine with a mid priced pump from Oriellys auto parts, no problem so far.

John. I had this problem in hot humid weather and installed an Airtex and added some wrap insulation. Problem solved. 8 years and going strong

Thanks, where did you place the insulation? I already tried foam pipe insulation on the fuel rail in the engine compartment with no success. After a 15 mile run in 80F+ degree weather the underhood temperature is about 150F. If I recall, fuel rail input temperature about 96F and return at the fuel pressure regulator about 120F. I think I am going to go with a new Bosch OE pump and save the old one in case I end up doing the overly complex official Jaguar dual pump modification.

John.I wrapper the pump.Fluttering of the pumped is caused by the temp under the car.

Yes, the 1988-1990 Xj40’s fuel pumps are external and located in front of the driver’s side rear tire. They changed this designed in 1991 to address those cooling issues you are talking about. Starting in 1991, they were submersed in the fuel tank so the fuel could help cool them down. Personally i love the external pumps better because they are easy to get at and replace without the expensive cost of dropping the heavy fuel tank to do the job. I also though Bosch was the OEM unit but i could easy be wrong. Ill look for the Walbro name in the future.

Yes, Bosch is the OE brand that Jaguar used. And an update on my fuel vaporization issue. I had a new Bosch pump installed and have also wrapped the rear mufflers and pipes near the fuel line with fiberglass manifold insulation strip. (many vendors of this material on Ebay, manifold insulation wrap) Also wrapped the fuel rail and some of the fuel line in the engine bay. So far even with a 3 hours drive in 96F weather no re-occurrence of the issue. Will continue my experimentation and maybe take some photos of what was done.

Depends which side of the pond you live, some drive from the correct side of the car :slight_smile:

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There is no correct side, that is why I always make a point of stating LH or RH, not drivers side or the even more confusing, “off side” or “near side”. The OE location of the Bosch pump is not far from the heat generated by the LH intermediate silencer and that is why I have wrapped it with with insulation. We will see if that, and the other changes made, address the issue.

John you cut off my smiley face :frowning: