!994 XJS convertible with the 4.0 L engine. The fuel gauge reads 3/4 when the tank is absolutely ,no mistaking it, full. Is there a way to correct this? I did a search and didn't find much on the subject. \
Bruce.

 

Bruce,

Search for "anti-slosh module" Youll find a number of posts including my directions on how to bypass it which will at least determine if that's the cause.

Cheers

Paul

 

1. Definitely investigate the anti-slosh module. That could be the case, and you need to make sure that's not the cause.

2. It could also be a bad fuel level sender. That's a relatively simple replacement. Make sure you buy a new gasket to go with the sender. If that's not it, it could also be...

3. Your fuel tank is impacted. The Rochester valve is likely blocked. You need to either replace it, or clean it. People seem to believe you can clean it. I don't have any experience with that. If you don't address this issue, eventually you will have to reseal, or replace the tank. After a good drive, if you sit in the car for a few minute, do you hear some kind of bang? To fix your problem, eventually you'll have to push some compressed air into the tank, but not a lot, or you'll bust the seams. Not worth the effort, until you have addressed the vacuum problem. I didn't get a whoosh sound from the tank when opening the fuel tank, but I did get a bang, or loud pop sound after a drive, usually a few minutes after the car was shut off.

 

Investigating the slosh module will be on the schedule come spring , never heard of one before . That's why I'm here , to learn things. I'm putting the car up for the winter this weekend. Ive only had the car 2 weeks and sorted a number of issues already thanks to reading a lot of posts and asking for help here on the forum.
Bruce

 

Plenty of posts regarding the antislosh module. Once you find it, you just jump two contacts together and if the gauge doesn't correct itself, plug the module back on and move to the next suspect.

The fuel level sender, that can be replaced when you're low on fuel to make sure it doesn't flow out of the sender hole when you remove it, just make sure you have the gasket on hand as well. I think anything below 1/4 tank is safe.