Starting problems resolved a few days ago (thanks to all) and we've enjoyed a few short runs in the car as we develop some trust in it. The next set of problems are presenting themselves, the first being a fuel odor in the cabin.


Drove the car about five miles on a warm afternoon with the A/C on and parked it for about 1/2 hour. Everything was fine, no odor. Half way home, again with A/C operating, we began to detect a fuel odor which became stronger with each passing mile. Once home I began a cursory inspection; the odor seemed a little stronger towards the rear of the car but no leaks visible. So, where do I begin? Where are the most likely, or most common, sources of fuel odor in this series? Our 1987 VDP was plagued with leaky fuel tanks (please, not again!) and took forever to completely resolve.

 

Check your injector hoses
My car had a pin hole leak in the fuel rail smelt fuel for a long time before it was diagnosed

 

If you think that the odor is strongest at the rear of the car, I would check under the car. The feed and return pipes exit right above the diff, hard to get at but you can see if anything is leaking. Next follow the feed pipe to the fuel filter. It's quite possible that the leak is at the unions of the filter. Have someone switch the ignition on and off a few times as you do this as it will allow the fuel pump to activate for a few seconds each time and keep the line fully pressurized. You can then follow the lines forward to the engine bay.

Also look at the carbon canister(s) and ensure that the connections are secure.

Undo the gas cap. If feel,hear a rush of air/fumes, it's possible that the tank is over pressured due to a faulty rochester valve and is activating the over pressure vent.

 

Removed all of the panels in the trunk and then got under the car with the wife cycling the ignition key. No visible leaks at the tank or at the filter. No pressure evident when the gas cap was removed.
The vapor line, welded to the top of the fuel tank, is connected to a large, black plastic cap on top of the tank via a short piece of hose. At the end of the welded vapor line is a connector, connecting a hard plastic piece of pipe that goes off behind and below the tank. That hard plastic pipe is tucked in and is kinked in at least two places - I don't see how much of anything is passing through it. It isn't wet at all but I suppose fuel vapor could escape.
Question: for testing purposes what would happen if I plug the hose connecting the welded vapor line to the large black plastic cap? Also, how does air enter the tank to make up for the fuel used? Would plugging the vapor line prevent the tank from draining fuel?
My thought is, if I plug the vapor line at the source and the fuel odor goes away I have found the source and can address it. Anyone??

 

Since the fuel odor is present only after the car has been run for fifteen minutes or more I am assuming whatever leak we have is slight and might evaporate quickly and not be visible. Although, as Allan said, I could see the feed and return lines up to the tank I couldn't see a leak. It doesn't look to be too hard to remove the tank, but has anyone had experience in doing that? Are the lines flexible enough to pull the tank far enough to inspect the connections thoroughly? Or can the connections be inspected by removing the back seats?
Also, the Rochester valve is either not present or not where the service manual illustrates...or I just couldn't find it.
I still suspect the vapor recovery system because, unlike our old Jag with leaky twin fuel tanks, there isn't a fuel odor when the car has not been running.