Running that final test is what I call taking the middle man out of the equation. Good news is that your fuel tank doesn’t have to come out. That gives you all that extra time to beat your head against the wall figuring out your other problems.
Since your pump runs with negative and positive wires running directly from the battery it SHOULD also run with the positive wire from the battery and the negative to a ground in the trunk. Does it ?
Looking at your schematic it shows the fuel pump ground wire running through the “protection module”
that I mentioned earlier (item 25 below) …
Can you track that down in the trunk and read it out?
Mike & Grooveman, I really don’t want to admit this but I’ve spent the last two days running down a rabbit hole, not that it’s all bad, there are still thing that are relevant. Turns out I was at the wrong relay in the trunk. I discovered this today while reading other post with regard to fuel pump issues and a post by Bryan_N. What tipped me off was when he said “Black Base above BFM”. I feel like an IDIOT.
So now that I was at the correct relay when I jumped pins 30/87 the pump Runs continuously. What still seems relevant is the fact that when I jumped the Blue/Red wire to the Battery and left the Black ground wire in place the pump did not run. The other issue that still exist is the ½ sec. prime, it still does not happen every time I turn on the ignition, just the first time after a rest.
Now if I pull the EMS relay on the bulkhead and jump 30/87 I get the half-second ‘whirr’ of the pump every time I jump the pins. Truth be told, when I think about it, if I had spark and the Jag didn’t start that might be the time to chase the fuel pump, at lease now we know the pump runs, it’s just the prime that may be a problem.
Addressing Mike’s question I have checked the trunk ground and resistance of the ground cable, it’s all good.
Grooveman, that’s the the Black & Blue/Red wires that plug into the top of the tank, photo 2 in post 16.
Hi Jagman After reading your post I have just been out to my car to run some checks and my pump does not do the 3 second priming burst EVERY time. If I leave it a couple of minutes between each test then I can clearly hear the pump run for the 3 seconds or so, but if I repeat the ignition on/off sequence without waiting for a short while between, then most times I can’t hear the pump prime but only a click from the boot area. The car has been starting and running perfectly so I’m certain the fuel pump is working exactly as it should.
Casso, thanks so much for the confirmation, that was my thought too, that once primed it has to wait a while to bleed off the pressure before it primes again. I really appreciate you taking the time to check that out.
I got my information from another post that stated "• Turn ignition ON, Do you hear the fuel pump give its half-second priming burst? [You can repeat this many times and you (or an assistant listening at the open filler neck) should hear the half-second ‘whirr’ of the pump every time you switch the ignition ON]
My gut feeling is the limp home mode is related to the no spark issue. I’m guessing if the ECU senses the engine is unable to rev high enough for a smooth gear change due to an EMS issue, it disables top gear.
If you keep in mind all the replacement parts you’ve fitted along with the extensive series of checks and tests you’ve carried out, once you solve this no spark problem you should be able to drive it to the moon and back without worries ! Fingers crossed that’s very soon.
I totally agree that the two issues are related and once I get spark the limp mode will clear up. I now have the best understanding of Jag electronics than I have ever had in my 17 years of owning this Jag, however, not as much as many Jag owner in this forum, and obviously not enough to solve the issue.
I re-ran a test I did over the weekend that really had me baffled. The test was jumping from the battery positive to the Blue/Red wire (hot) of the fuel pump while leaving the ground wire attached to body ground. When I did this the pump did not run. This simply was not possible as I had checked continuity from the ground wire at the grounding point to the connection and had tone. Today I re-ran the test to see if it would repeat, it didn’t. When I jumped to the positive terminal today the pump ran (see photo and post 19). While I was sitting in the trunk scratching my head I realized when I ran the test over the weekend the battery was in the trunk but not hooked up to the car so no body ground to the battery when I ran the prior test, mystery solved. I consider this thread CLOSED, Thanks to all who have contributed. If anyone has questions PM me.
And one final caution: While employed with Jaguar Land Rover North America I learned of a technician at a dealership who was doing a lot of similar work with the tank/pump/connections in the trunk or possibly emptying the tank for removal. Somehow fumes collected in the bottom of the trunk and his work with jumping connections and testing caused a spark and a flash fire that blew him back out of leaning over the trunk and singed his eyebrows! Quite a surprise learning experience and could have been far worse. Luckily he was OK and there was no continuing fire but just a word of caution when working with gasoline and electrics.
