08 XKR. Hi folks. Let's see if you can help me figure this one out.

Without anything noticeable having happened, the check engine light popped on with codes, Po174, P0171, P0430 and P0088 (high fuel pressure). I cleared the codes and the first 3 didn't come back. P0088 didn't return either, but..

Not a day later, I left the car idling for about 10 minutes when it began running very roughly, wouldn't react to gas pedal movement, and eventually stalled. I immediately restarted and it was perfectly fine and ran like nothing had happened. However, if I let it idle for more than a minute or so, the roughness returned. No codes thrown during this episode.

Coincidental to the above, I also began noticing a "hum" from the rear that I couldn't quite place.

Cut to the next day. I take the car out and before I leave the neighborhood, I get what sounds like a muffled air raid siren from the rear. I check under the car and the fuel tank is vibrating (a lot). It was accompanied by a new check engine light of P0087 (low fuel pressure). I shut the car off, then restarted and the noise went away for about 20 seconds, then returned. Oddly, the sound that I hear from the tank isn't audible through the fuel filler (I expected it to be loud).

The car was at a point where within a minute of starting the pump starts humming and then abruptly started screaming. It wasn't a gradual change in noise. The change from hum to scream was instantaneous - like a switch being clicked. If I shut it down and restarted, the noise went away and then consistently returned after "about" 20 seconds. As mentioned before, the whole tank was vibrating when this happened.

Cut to this morning. I set out to record the sound but it wouldn't do it, so I took it for a drive. 5 minutes in and the sound returned. Figuring, "what do I have to lose" I floored it (safely) to redline and the sound went away. I drove for 10 more minutes with no sound. Just as I pulled into my driveway, it was back. I decided to take it back out and did some hard braking to see if sloshing the tank would do anything (it didn't). I pulled out and floored it again, and the sound was gone. Thirty minutes of driving and it hasn't returned, but I did get the P0087 again.

Thoughts?

 

lift up your passenger (US) side back seat, they pop out
under neath is a rubber cover for the fuel pump, you will know if thats it.

 

The fuel pump is experiencing a blockage of some sort, causing it to vibrate.

 

I had a fuel pump display the classic intermittent fuel starvation characteristics once so I had to replace it with a newer one. When I pulled it out of the tank I tested it again and found it to be dead. About 8 months later I took it off the shelf(Don't ask me why it was still lying about!) and tested it again and it worked just fine. Bottom line is that these things are pretty finnicky. Oh, and don't let anyone lead you to believe that you can change it out without pulling the tank out or without making a cut in the seat area. The Jag engineers were just smart enough to locate that hole off center enough away the tank access port to not be able to remove the pump. Fine for inspection though!

 

Haha! For starters, I was unaware that an access(?) cover even existed.
The next time it acts up (hoping it doesn't) Ill pop under there to see if that is definitively where the noise is coming from.

 

Seeking advice/tips/tricks/gotchas from members that have replaced their fuel pump.
I've already determined that a 'through the floor' replacement can't happen without some serious structural mods.

 

how many miles are you at?

The drive shaft and exhaust system must be lowered to remove the fuel tank...

 

Last I checked, around 155k.