1989 XJ40 fuel tank vacuum canister

XJ40
1

Over the years I’ve been plagued with an intermittent fuel smell in the trunk and in the cabin. It doesn’t bother me that much (well maybe a little) but my wife goes into her high drama mode … grabbing her throat and rolling out of the the car gasping for air (but actually she does have a great sense of humor :grinning:).

I’ve pulled the tank out twice over the years and it’s been in perfect condition. Not a trace of corrosion on the outside and nothing I can see on the inside with a long borescope. Both times though it appeared there was a very small stain around the top hat … On my '89 with the external fuel pump the fuel tank has a small metal dome on the top, fittingly called the … top hat

Both times I’ve removed the tank and had the area around the “top hat” resoldered with good results …
temporarily .

SO THE QUESTION BEING … is anyone familiar with my fuel tank vent system and how it actually works? The charcoal canister has several check valves and is vacuum actuated, but before I get down and dirty with it I wonder if anyone has already been there.

Again remember it’s an '89 with an external fuel pump.

2

The purpose of the purge valve is to redirect the fuel vapors from the tank to the intake instead of releasing it into the air. I just replaced the electrically operated one. I’m gonna replace the other one too, the vacuum type. The day before I changed the valve, my car ran so badly that pushing the gas pedal made the car go slower. That was in the morning when I went to work. The engine also stopped on the main road while idling. I guess the vent pipe from the tank goes directly to the charcoal canister then the vapors go through the two valves before entering the inlet.