Hello smart people,

Looking at a 2001 XJR for a friend. He had stored the vehicle over the winter in a dry space. Inadvertently he had connected the battery leads backwards after trying to start the car. I have pulled all of the fuse box covers and found only one blown fuse. After starting the vehicle on an alternate fuel source we have narrowed the problem down to being fuel related. I have checked the injector wires and have power to them, fuel pump relays are clicking at least. Vehicle has spark and will run on a whiff of propane gas. I believe that we are not receiving a ground signal to the injectors. I plan to confirm this shortly this week as well as confirm fuel pressure. Other than a now failed PCM what might be inhibiting the injectors from pulsing?
Thanks all.
Niels

 

Have you checked the fuel filter? ...they can and will gunk up after time when left unused.

 

Highhorse
Thanks
Something else worthwhile to look at.
Niels

 

Definitely check for fuel pressure at the Shrader valve as a first step. My car sat for two months after the semi truck delivered it from Florida to Texas. It was driven off the semi and around the block with no issues before storing it in the garage. Dead battery when I attempted to start it after the two month storage period. Charged the battery...no start. No pressure at the Shrader valve. No pump sound when I hot jumped the pumps at the fuses. Bottom line....fuel pumps failed sitting in the garage! Sounds crazy, but there are other reports of the same voodoo happening. My adventures changing the pumps are documented in an earlier string.

 

Thanks,
I'll check pressure next time I am able. Need to locate shrader valve first. Would be thrilled if it turned out to be a delivery problem and not an injection issue.
Thanks
Niels

 

I wish I had a photo....but the valve is in the "valley" and at the left forward end of the fuel rail...just aft of what looks like a lifting loop/hole in the engine casting. You'll have to lean over the left fender and look back under a snag of wires (forward injector) and intercooler hoses at the left corner of the engine to spot it. Mine had a light blue cap on it....looks very much like a tire air valve sticking up almost vertical from a small black hose or pipe that dives downward and under the supercharger snout. Find that lifting hole in the aluminum casting and you're in the vicinity. The threaded cap can be removed with a long needle nose pliers. Good luck getting it back on...

Yes, replacing fuel pumps would beat chasing electronic problems, but not by much.

 

The fuel valve is pretty well hidden on SC engines. This is a 1999 AJ26 (blue valve cap):

 

Hi all,
Update this evening. Noid light confirms injector pulse. Yippee! I was able to locate the schrader valve. Thanks for helping me locate it. As stated above its on the front left of the engine, little blue cap now located somewhere in the valley of the engine. No fuel pressure, zero not even a dribble out the valve. So it's a delivery problem...

 

Special tool for removal of blue caps:

 

QUOTE=burntatf;2196425]Hi all,
Update this evening. Noid light confirms injector pulse. Yippee! I was able to locate the schrader valve. Thanks for helping me locate it. As stated above its on the front left of the engine, little blue cap now located somewhere in the valley of the engine. No fuel pressure, zero not even a dribble out the valve. So it's a delivery problem...[/QUOTE]

If you happen to spot the little blue cap, please let me know the location as mine is likely residing in the same hidey hole. I put a push on rubber cap over the shrader valve to keep the dirt out in the interim.

(Clever tool, M.Stojanovic)

 

Owner has agreed that we are as far as we can go where the vehicle is located. We will have it towed to my shop where we can get it onto a hoist and finish up the investigation.
I'll keep an eye out for the cap ...
Niels

 

Below is a Jag-Lovers link to my fuel pump saga (in case it's not the fuel filter). There's some good advice along the way, and a bit if not so good advice. But you can filter out the chaff.

If you have a car lift, the tank removal process almost certainly makes more sense than going through the parcel shelf. I was virtually forced into doing the repair in my 99 degree garage as it would have been near impossible to maneuver the vehicle outside, up a steep incline, and onto a truck or trailer. I'd suggest you check the fuses between the relays and the pumps. If they're not blown I'd remove them and try to activate the pump with a jumper wire from the outbound fuse terminal. You should be able to hear each of them running in the tank. If not, you found the problem. If they can be heard running, it's probably the in-line filter that's buried up behind the left rear wheel. My money is on the pumps. There's a discussion about pumps in the attached string. The Delphi pump is close to a perfect fit in the original rubber isolators...very minor trimming with an exacto knife. Some guys have found them for under $40. Releasing the fuel lines at the bottom of the tank are apparently the biggest problem if you go the removal route. Access to a lift should mitigate that obstacle. Motorman advised me a while back that he does the job by dropping the tank off its "shelf' and supporting it on some boards while still in the trunk itself. He leans it rearward once the wires and hoses (top and bottom) are disconnected. Be very careful removing hoses from the plastic emissions cover at the top of the tank as it's easy to snap off the spigots. (Personal experience).

Here's that link: https://forums.jag-lovers.com/t/2002...o-start/381779

 

If none of the checks mentioned work, then its pump time.

Pulling the tank is not as much of a bitch as its being made out. The effort in that thread to get through the deck and the fact the fuel filter has to be replaced anyways, means you'll have to get under her anyways and will take just as long to slide it back in the trunk. I'm not saying its fun, but your not hacking it. Btw...I recommend replacing the filter first since you don't have anything in the lines. Dave has one... https://shop.everydayxj.com/XJ8_XJR_...003_s/1841.htm

Pay attention to what your doing as you remove/replace it and all will be fine. As I've stated in tens of threads...I worked mine back on (2) cut to length 2x4 for over the spare well and battery well. It only has to come out to the opening of the boot and I did it in a little less than a day and I have 2 pumps also. The one bearing factor is how much fuel is in it?

The biggest bear is if the fuel lines won't disconnect using the A/C Fuel line removal tool. Most do come off, though it doesn't seem like it from the posts here, because no one complains when it goes correctly. Mine didn't release ..so we won't discuss needing to make a tool to release it unless you have it. Just don't pull the tank without releasing them or you'll kink them and be F-----....errr, up the creek without a paddle.

Some screenshots for review....

 

I believe the screen shots are for an XJ8 (single pump). Slightly different hose arrangement at the top access cover (more of them on the R). I'm not sure what the side access cover is for in the depictions, but that cover is not on an '02 "R" gas tank. The basics are much the same, though.

The beauty of "hacking" through the parcel shelf is that the next couple of times the pumps fail I'll be able to complete the job in a few hours without having to tow it to a location with a lift or wallow around under the car on the side of the road. Jaguar should have put a hatch over the top cover in the first place instead of building the car around the gas tank.

 

AMEN!

 

Can't argue with that perspective...

I believe those pics are for an AJ26...so up to '99.

 

Hi all,
Update. Towed the jag to our shop, raised on a hoist cracked lines to fuel filter cycled key no fuel. Bypassed both relays and still nothing. Removed tank (wasn't terrible) Bench tested both pumps, DOA. nothing from either one. I can't imagine both pumps dying at the exact same moment. Are these R models capable of running on one pump? Speculating that one pump may have died in the past and wasn't noticed then when the second pump expired over the winter we had a no start. I have a new set op pumps/strainers ordered for the morning we should know by the end of day tomorrow.
Thanks all for the input/experience/great ideas.
Niels

 

Well, mine both died at the same time and there are a few other instances reported on site of it.

 

My understanding is that the "Restricted Performance" alert comes on when one pump fails, and that's what I saw when I was trouble shooting by pulling relays.. No alerts when both are dead. So my car is another example of both failing while just sitting in the garage for an extended period. Ethanol seems to be the link. I read one old post where a member cut open a failed pump and found deterioration of plastic bearing carriers (or maybe it was brush carriers). Let's hope that newer pumps are ethanol resistant. Interesting that my neighbor across the street had a failure in a similar vintage, low mileage Ford pickup. He either had to drop the tank or remove the bed to access the pump. He removed the bed. (I recommended a Sawzall).

 

Solved!!
Thanks to all who chimed in, you steered me onto the right path. I suppose the reversed battery connections must have been a red herring. She started and ran just fine after the new pair of pumps were installed. It's interesting how they plumb both pumps into a single fuel line to feed the fuel rail. I'm planning on changing out the fuel filter as well.
Thanks again
Niels