Rned out ti1994 xj40 fuel delivery problem

I don’t know if I need a mechanic or a Jaguar medium. My car cranks strong but will not fire. I can spray starting fluid directly into the idle speed control and she’ll start right up and run until the fluid is gone. I do this 5 or 6 time before she pulls up enough gas on her own to continue running. At this point she runs great and restarts on demand until she’s left overnight.
Repeat process in morning!
I have had this same problem (symptoms) three times in the past year.
1st time cause turned out to be with the fuel differencepump canister blowing the pressure line off leaving the pump returning fuel to the tank.
2nd time turned out to be a faulty 4 pin relay which delivers power to the pump. Easy fix.
3rd time to be determined. There is one curious difference though that suggests I seek a Jaguar medium. During this process, the battery never failed to spin the starter, interior lights never failed to come on when I opened the door, however, a few times she did start and run, I had to reset the radio code as if the battery had been disconnected. Would there be a common power source or ground connection between the fuel pump and radio?
As always, any suggestions and/or comments no matter how farfetched would be greatly appreciated. Thanks for any and all replies…

Sounds like a failed fuel non-return valve. Have you tried the classic key-cycling trick (well documented in the archives)?

Ditto on the key cycling trick on, off, on, off, on, off, on and try to start.
Having to reset the radio code sends me to the battery failing, if the volts drop to or below 10v she aint going to fire.

In addition to Mike’s cycling tip, swap the oxygen sensor heater relay on the firewall with the one next to it. The oxygen sensor heater relay also controls the pump.

Thanks Mike for your suggestion. The fuel non-return valve, is that also called the pressure control val ve atthe front of the fuel rail. There is a vacuum line attached and a hard tube with some kind of small diaphragm looking thing (not shown in my manual) just before the metal tube connects to the rubber tube to/from the tank. There is also a unidentified valve/diaphragm on top of the fuel rail at the back if the engine.
Are any of those what you are referring to?

No, AFAIK the non-return valve is in the tank, pump canister. You can fit one in the engine compartment though, some stuff on doing this in the archives.

Thanks Larry, I have an appointment to take her to the mechanic wednesday. He also mentioned about the oxygen sensor when I last talked to him. I will definitely have him check that.
One thing I forgot to mention, on a couple occasions when the she started and was idling normally there would be a loud sound of rushing intake air as if a big block v8 with two 4 barrel carburetors suddenly put the pedal to the floor.
It lasted for several seconds and then resumed normal. I did not notice any outrageous increase of RPMs.

The oxygen sensor itself isn’t going to affect anything starting from cold, the oxygen sensor HEATER relay -if faulty or corroded will prevent the fuel pump from running. You can check it very easily by substituting, say, the A/C relay and see if that makes a difference - 2 minute job, no need for mechanic!

To aid with the identification of the relays::

'93 / '94 cars with SIX relays on the firewall are served thus;-
Black base = EMS fuel injection main relay
Green base = A/C clutch relay
Yellow base = Oxygen Sensor Heater relay
Purple (Lilac?) base = Auto Transmission power relay
Blue base = Engine Breather Heater relay
Red base = Air Injection Pump relay
[If there is a SEVENTH relay it is the 'Ignition ‘ON’ relay in a white base]
Relays are p/n DAC7686 (lt blue non-sealed) → JLM21842 (black sealed)

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The fuel pressure regulator is located on the front end of the fuel rail, the smaller diaphragm towards the rear of the fuel rail is a damper, when that fails it doesn’t affect the running of the engine but it can produce the ‘Helicopter’ sound.
To check if the FPR is not deteriorated you can pull off the small pipe to check that there isn’t fuel being pulled into the inlet manifold. Item 6 is the FPR and item 11 is a vacuum pipe, there should not be any petrol in item 11

The battery is about 6 weeks old best quality autozone sells. And because I’ve been doing so much cranking on it I’ve kept a maintenance charge on it.

New information on the on going problem above. I have lately discovered at times it will start without ether stumble and die within 5 seconds. When I restart and rapidally feather the gas pedal she will run rough between 200-500 rpm. Eventually I can get up to 1000 rpm where it will idle there smoothly. At that point I can work the gas pedal and rev the engine, no hesitation with smooth normal ldle.
At this point I notice a new symptom. I can run the engine up to 2500 and there is a unfamiliar loud intake air sound.
2500 and above that rush sound stops and intake sounds normal. Ease her back down to 2500 and the loud sound returns. Then suddenly I hear what sounds like a baffle closing and the intake sound suddenly becomes normal at al rpm.
Does that situation give anyone a clue as to what is going on?
Also, for future reference, what would be required to install an in-line jaguar fuel pump and would I have to remove the in tank pump. Comments and/or instructions on this would be helpful.
And again, any and all comments are greatly appreciated.

This may be a clue - or a mere coincidence:

You might try removing the air pump relay (in red base on firewall) and see if there is any change.

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Gary, when the blue donut seal-that’s located at the fuel pump outlet- had burst, I heard a popping sound in the engine bay around the inlet or the air filter (couldn’t exactly pinpoint it). When I checked the fuel pressure, I disconnected the feed line from the fuel filter and attached a hose to it and I put the other end in a half a gallon bottle. The pump has to fill it in about a minute. It took ages for my car to get up to 40-45 mph.