Jaguar is the 1999 XK8 convertible, normal aspirated, 53K miles, which I just finished replacing the timing chain tensioners, and cleaning up engine parts for "showing" as I reassemble. That is done now, but since it was "down" for a long time (a hobby, took my time being really careful) and now it won't restart. I know the chains and setup is tight and right, turned it over ok by hand a lot during re-assy (incl. double re-checking cam timing). What I do see is that I am not getting fuel pressure at the rails, and I suspect the fuel pump has quit / locked up, after sitting idle for a very long time. I previously had an XJS 1977, and I remember the humm its fuel pump would make. Can anyone confirm that I should HEAR SOMETHING HUMMM on this XK8 with single pump (as I heard on a past 77 XJS) ? I have jumpered posts 3 and 5 where the relay goes in, which should force the pump to run, but I hear nothing. I know there IS 12v there. So I am taking this pump as dead. If anyone could offer advice, esp. confirming testing it in place and especially what I should hear, it would be much appreciated. This is a convertible so I know I cant access the pump thru a woofer mounting hole (only possible on the coupe).

Chuck P (DoubleCat), Pittsburgh Area of PA

 

Sounds like you already did your homework and confirmed it is the pump.

Your scenario on it happening after a long period of not running is very common.

Just be aware the electrical noise filter on the link lead to the pump, which is also inside the tank, may also have gone open.

 

Just to confirm that you should hear the pump for a few seconds after turning the ignition on - the noise, as you mention, is a humming sound. I take it from your post that you have checked the fuse?

 

Many thanks to both of you, batroute and WhiteXKR. Having confirmation to look for the brief humm ... exactly as your described, is quite useful to know. I suspected it should be there (ala the 77 XJS I used to have), but having very little road experience with actually using the 99 XK8 yet, I had not yet had occasion to notice how XK8 fuel pump should sound. Indeed, mine does NOT make that sound. Yes I did check fuse, and even more so. I took out the closing panel to expose the tank, found the right wires on the harness quick disconnect and checked what was going directly into the fuel pump. On cranking, confirmed there was voltage going in the leads, but no pump humm, no pressure at the fuel rails, and no starting. So then I uncoupled the connector (to fully isolate the pump wires) and fed a full 12v directly into the leads of the pump, and still nothing... though there was a baby spark when I touched the battery terminal, and the intentional skinny test wire I used was a little warm. That said to me that the rotor in the pump is definitely stuck/ seized, as motors suck more current when the rotor is locked.

Anyway.. those are the gory details, and it's pretty obvious. I think that also says I dont have an open lead on the electrical noise filter, but I'll still look closely at it once I get it out. Not looking fwd to the pricing. I hesitate to walk right into the dealer for a financial beating. Any suggestions of other places to look? or the least expensive source of actual genuine Jaguar pump?

I also found your comment about fuel pumps not working after sitting a long time, good confirming evidence of the problem. Now that i think of it, I had the same happen quite awhile ago in the past, when I had a 82 Supra down for 9 months over a cracked cylinder head. And guess what it also needed after that 9 months of sitting (I was fighting with the rep over a defective head that cracked in the inlet passage, seeping coolant into the combustion mix)... yup a fuel pump.

Many thanks again for your replies.

DoubleCat (Chuck P)
1966 E-Type Roadster
1999 XK8 NA 4.0 53k miles

 

When my Pumps failed (after winter storage) one of them did draw current (initially) but eventually was open circuit. It sparked but did not run (but did not draw enough current to blow the fuse).

Replaced both Pumps.

Now, during winter storage, I remove the relays every week or so and jump the socket contacts to "exercise" the pump(s) for 10 seconds.

When the pumps are running properly, they make a fairly quiet "whirring" sound. You have to be in a quiet area to hear them running.

 

Your Fuel pump has 2 fuses and a relay. See if this will help troubleshoot you problem

Link JagRepair.com - Jaguar Repair Information Resource

 

Just wanted to ask WhiteXKR and batroute, or if anyone else has a suggestion ... would you go with a genuine Jaguar C2N3866 (avail for $225 from a mail order Jag dealer) or a Bosch (I found Bosch W0133-1604306 Fuel Pump $104 described as a "direct fit") , or is another model you might suggest, better for reliability ? ... I don't care about the price diff, but I DO care about not having to go back and do a re-install, or if performance (life or pressure/volume) is inadequate. Please let me know .. thanks!

 

I haven't changed a fuel pump on my XK8 yet(but watch this space because it will have been standing for five months by the time I return to Florida).I have ,however, changed pumps on other cars and used generic rather than genuine parts. Manufacturers have enormous mark ups on spares and also often prevent the supplier from supplying the aftermarket factors until a certain period has elapsed. Nevertheless it is often possible to source an OEM item at a substantial discount via the independents after a bit of digging. Bosch is a good brand and if the spec. on the pump is the same as the Jaguar item(Denso perhaps??) with regard to fuel flow and pressure I personally would use it. Let me know which one you decide upon in case I've jinxed my pump by talking about it

 

The OEM pump was made by Walbro.

The Denso pump listed as the equivalent needs the rubber collar trimmed. It does work well though. There is an older Denso number which includes the strainers, but it is hard to find.

 

RockAuto lists the Denso unit for $90.79

http://www.rockauto.com/catalog/more...142&cc=1355914

I think this is what you need. I might be wrong tho.

 

I can only comment on my limited experience. I replaced my pumps about a year ago with Airtex pumps (which are stocked at many Advance Auto parts stores). They have been fine, but the hose nipple is not flared. This presents a hazard of the hose slipping off over time. I have not had this problem (yet), but I probably would not get them again for this reason.

 

Many thanks to the many of you that shared your experience and responded to my query about choice of fuel pump.. Jaguar supply vs Bosch or other. The info shed light on several aspects of exactly what I am seeing so far. Starting to take the tank out today ... convertible so can't go thru the woofer, and right now I'm not inclined to cut a hole in the rear shelf of this convertible, unless the lower hose disconnect is unyielding.... but then I've fought with tough repairs before, and still come out swinging. I'll keep you posted, with what I find, and what pump I go with. thanks again!

 

This might help if you wish to read it

Link JagRepair.com - Jaguar Repair Information Resource

 

Don't want to hijack your thread, The day I bought my 2000 xk8 the fuel pump failed three hours later. I assume also from disuse. I got towed to a local shop and they replaced the pump from there're local supplier. Now I have a high pitched whining noise from the pump. Any Ideas? David

 

Thanks Gus for the link to the PDF about removing fuel tank on a 2000 convertible. I'll be running out tomorrow to get the Autocraft tool set from AutoZone that is pictured in the PDF of the link you cited. I'm using that procedure along with info from the JTIS factory disk, and the tips I've read so far in the forum.

In the above thread, I noted some questions about choice of which pump, for me it was between the Bosch pump and the Jaguar part. I decided on the genuine Jaguar pump, though double in price (yes they mark up double or more). It's supposed to arrive tomorrow. After installed, I plan to also follow advice from the above thread, of manually tripping (bypassing) the pump relay to force the pump to run (recirculate) for at least minute or two (or more), each week, unless it gets driven. I am now concluding that "exercising" the pump is vital. I have also been wondering if regularly using fuel injection cleaners, and maybe "Sta-bil" fuel stabilizer over the winter, will also help by keeping the "stickies down". I suspect these pumps are pretty vulnerable to the slightest of fuel varnish buildup. That's the action I plan on down the road, once I get the new pump in. Watch this thread... I'll post progress.

As to the question that DNJAA asks above, maybe there's sediment in the tank. If you have someone open it up again, I would be sure to have the "sock" (strainer) replaced, and I would suggest having your mechanic check for debris in the tank, and possibly flush it out really well. I would wonder if that is causing the whining noise. Do you know if your local shop put in a genuine Jaguar pump? Not sure if that matters but minimizing the risk of various things going wrong is why I chose the dealer pump is the end. But there is are lots of pros and cons on that choice, and I agree its difficult to really know how much that matters. But I do think that system cleanliness and no varnish buildup are majorly important. Good luck.

 

My fuel pump and filter

Link JagRepair.com - Jaguar Repair Information Resource