I am in the process of finishing up the bodywork on my XJS H&E and had a question for all forum members.
As you may be aware the H&E version uses 2 fuel tanks. 1 inside the car and the other in the original position in the trunk. The tank in the trunk is modified so that the convertible top can fold flat with the body of the car.
I have been working on the fuel system for some time now and no matter what I do, I have a strong fuel smell in the car if it is left sitting for any period of time.
Here are some of the issues:
I have installed low permeable marine fuel hoses throughout the system but the fuel smell persists.
The new lift fuel pump installed in the tank inside the car is very noisy.
I can't get the Rochester fuel gauges to work.
All of the Evaporative System components are in place and functional.
MY PLAN IF FEASIBLE:
Remove the 2 fuel tanks and install a single 21 gallon fuel cell in the trunk.
The tank I am looking at measures 24" L x 20" W x 10" H from Summit.
The other choice is to get a tank custom made but that will cost $$$$.
I measured the space between the battery and the wheel well and there is enough space for it to fit but I will lose the space for the spare tire. To resolve the spare tire issue, I will be searching around for a donut style spare.
Doing the single tank conversion will simplify the system just by having a single fuel pump and less fuel hose connections.
The fuel cell will be connected to the original "SURGE TANK"
If you all have any ideas please feel free to post them. I will entertain them all.
If you have any question regarding what my plans are, please ask.

 

Sounds OK to me.

Speaking broadly, as I'm not familiar with H&E specifics, I would re-plumb as much as possible to the outside of the trunk. And, with your new tank, I wonder if your surge tank can simply be eliminated? Every chance to remove potential leak points should be looked at, IMO.

Cheers
DD

 

Sanchez
Here is a thread about this very topic. It contains various sugestions throughout. In the final post I made another suggestion with a diagram, and although mabe a bit dearer, it is in my view the most reliable one.
https://www.jaguarforums.com/forum/x...-pumps-236083/

It consists of losing a bit of the bottom tank's capacity in order to get a sump tank depression into it (maybe by using a tapering bottom the the tank) thus allowing gravity feed to an injection pump sited in the space created under the tank. Expanding the top tank into the boot loses you all the rear end shunt fire protection, not something I would do. I reckon you would lose about 3 gallons tops. And you could get the existing tank modded, so costs would be pretty low.

 

@ Greg: I do not believe that modification of the lower tank is feasible because of the shape of the tank. The lower tank sits on the floor of the car where the rear seat would normally go. The tank straddles the driveshaft tunnel. My plan is to completely eliminate this tank.
See attached photo.

@ Doug: I have successfully moved the EFI pump from the trunk to the underside of the car on an XJS which I have since sold. I can pipe the Fuel cell to gravity feed the fuel pump installed under the car and choose to eliminate the surge tank if I want to. I will be chewing on that while I decide which fuel cell I would want to use. I may also decide to relocate the battery so I can place the fuel cell in the center of the area where the trunk tank now resides. If I do it this way, the fuel cell will not go all the way in to prevent it from interfering with the convertible top. I will have to lose about 12 inches of trunk space but I am OK with that. The final position will be determined when I remove the tank in the trunk and lower the top to see how much space I have left.

 

Sanchez
OK, got it, in which case why not eliminate the part of the tank on one side of the tunnel (ie cutting and shutting it)? Then run the pump feed out of the unmodified side through the floor to an under-car pump and filter. No sump tank then needed, n fuel slop problems, no lost trunk space and no other mode either.

 

@ Greg: The fuel supply system modification I have in mind is to completely eliminate any fuel storage inside the car. That in itself will eliminate 4 areas of possible fuel vapor venting inside the car. 2 at the 1 1/2" hose connection between the 2 tanks, 1 at the pump flange and 1 at the fuel sender assembly.
I am willing to sacrifice some trunk space in order to have at least 20 gallons of fuel.
Sometime this week I will make a 24"L x 20"W x 10"H cardboard template box to see how it will fit and look.
There are some smaller tanks available but I think a minimum of 20 gallons is what I want to go with. A 21 gallon Aluminum fuel cell complete with AN fittings and a 90 ohm fuel sender and 2 vapor vents can be had for under $200.
The area inside the car will be used for storage with a hinged cover.
THESE ARE ALL IDEAS AT THIS POINT IN TIME.