Y2k Jag XJ8

[PhilA]

That and you might want to watch what the output of the knock sensors is doing, particularly at cruise RPM.
The little piezoelectric pieces are usually reliable but they can get noisy with age. You might have one that's triggering falsely when it's getting hot and that'll massively retard ignition for a brief moment.

[Hooli]

Aye that's true, they are a known failure point.

It's supercharger off to replace them though. I'll get them done when the valley hoses get replaced as they'll be in there anyway. That might be next summer when I get the coolant leak found.

[PhilA]

Fixed the Jag. Check engine light went out by itself.

[PhilA]

Warmer weather today, also mostly over the illness the kids brought home from school.

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Between reaching up the back left, and pulling the exhaust off (it undid and came apart, WTF?! No broken bolts, no fighting, nothing) I managed to get the quick release pipes undone out the bottom of the tank, which began the tank siphoning out of the breather, which was unexpected. Fought a bit and managed to get the pump running, which was on and off squealing a bad bearing. Pumped about 12 gallons out and pulled the tank from the car.

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Undid the lock ring and finaigled the top plate out. Looking inside, it didn't look so great.

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Definitely not so great. The swirl pot was full of what looked like coffee grounds.

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The pump looked like I had removed it from the Titanic. The rest was all rusty flakes. Yuck.

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Scrubbed the loose trash off the metal and cleaned it all up before putting a new pump in and hooking it all up.
Dropped 5 gallons of fresh fuel in and plumbed it all up. Bypassed the relay and primed the system. It burped and then continued to flow quietly circulating to the rail up front.

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Did the rest of it up and took it for a test drive. Filled the tank. Back on the road again, happy about that. I've missed driving it.

Phil

[PhilA]

Did a round trip tonight, average mixed driving.

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(24.6 uk mpg)
Ain't bad. It's officially faster than a Lincoln Town Car of the same age, even loaded 5 up with a full tank.

I'll check the fuel trim tomorrow, see if it's closer to zero than it was. I'm thinking it should be, given that the fuel isn't being strained through a Triumph Herald any more.

Phil

[Hooli]

That Triumph Herald kit* in the tank probably explains the fuel gauge issues you had too. I bet the wiper part was covered in it initially.

[PhilA]

The float felt a bit stiff to move toward the top, so maybe. I didn't fancy trying to undo the retaining screw to pull the sender off. It's working well enough now.

[PhilA]

Pulled the obd2 out last night and poked about in the memory on the Jag.

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A stored but cleared FUEL PUMP UNDERSPEED error- well, yeah- and the fuel trim is right in limits now for a well running engine so that's good.

Audio wires should be here tomorrow, I'll pull the interior apart and fit that. It'll be nice not to have alternator whine in the hi-fi.

Phil

[PhilA]

Occasionally the hifi in the car would get annoying ground loop whine because the RCA cables running to the amp in the back had broken connections, the shielding particularly.

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Had all the fun of pulling new wires through. Connected up, now a constant whine.
Turns out the main midrange amp has isolated shield on the input, like the radio, but the sub amp is bonded to ground, so that turns the bodywork into a giant antenna. Ordered an isolation transformer for the sub. That should fix it.

Phil

[PhilA]

Isolation transformer fitted. That was the fix.

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No more alternator whine through the speakers.

Phil