Fuel Tanks

Rusted Fuel Tanks

The rear quarter windows in the Esprit sit directly above the car's fuel tanks. It is speculated that if the windows start to leak this leakage will eventually lead to rusting of the fuel tanks and consequently to a fuel leak. The problem occurs because there is a piece of foam that sits underneath the fuel tanks that has a tendency to trap moisture. If water enters the tank area via the quarter window, it drips along its sides and gets trapped by the foam. After weeks and months of contact with the wet foam, the steel tanks start to rust and small pinholes appear at the bottom of the tank. This first becomes obvious when you get a fuel smell that won't go away even after you repair the Surgical Tubing Syndrome

Removal and replacement of the fuel tanks on an Esprit is by no means a trivial matter and can be very expensive. It involves removal of the engine compartment walls as well as some parts of the engine. Even with many parts out of the way, removal is still a pain in the neck. So fix that leak before it's too late.

Back to top of document

Fueling Problems

All Esprits have what are know as "saddle tanks". This means that there are two smaller fuel tanks (one on either side of the engine compartment) instead of one larger one. The tanks sit below the rear quarter windows and are connected together via a balancing pipe that runs between the bottom of the two. This pipe and the addition of a gas cap on both sides of the car make the Esprit one of the few cars in existence with the convenience of being re-fueled from either side of a gas pump.

The diameter of the balancing pipe in the older Giugiaro Esprit seems to be slightly smaller than that of the Peter Steven's Esprit. This combined with a different angle of the filler pipe conspires to make fueling an older Esprit quite a chore.

Many owners have come up with varied techniques to speed up the fueling process. Most of the variations of these involve keeping both gas caps open to allow air to escape more freely as fuel displaces the air in the tanks.

Back to top of document

Fuel Smell

In addition to being connected from below via the balancing pipe, Esprit's saddle tanks are also connected from above with a fuel vent hose. This hose helps gather fuel vapors from both tanks and route them to the charcoal canister. The hose travels along the inner top of the rear quarter windows, and over the rear window, where it is covered by some carpet trim.
Unfortunately, Lotus' reputation for choice in tubing material is almost as bad as its reputation for vehicle electrical components (Lucas). The tubing in question is described as surgical or fish-tank tubing. In this particular application, it is about 1/2 inch inner diameter and has a pale yellow color. Within a few years, the tubing material begins to rip, tear, or disintegrate. As this happens, fuel vapors escape the hose and can be smelled quite strongly as they enter the cabin via the seat belt holes on the bulkhead (firewall).

Luckily, not only is this problem very easy to fix, but it can be beneficial when it comes to negotiating the purchase of a used car. Most people selling used Esprits don't know enough about them to know that this isn't a serious problem, so they may be willing to discount the car further.

The simple solution is to remove the old tubing and replace it. Hopefully you will replace it with a higher quality fuel line instead of with the genuine Lotus replacement part. This way you can avoid having to repeat the repair in a few years.

I used regular fuel line or oil cooler hose material. Getting the right size is tricky. If you get the same inner diameter as the original hose, the outer diameter will be too large due to the increased thickness of this type of hose. The problem is that the hose won't fit correctly in the channel underneath the carpet. I used 3/8-inch fuel line instead. It was definitely a smaller diameter than the original but since it only is supposed to carry vapors, I figured the increased restriction would not be a big deal. The hose attaches to a plastic right angle elbow on each end. I replaced these with brass elbows and hose clamps of the right diameter to make the hose fit properly.

When you're done, re-glue the carpet with contact cement and you're done. Some people have recommended driving a few black oxide #8 self-tapping screws through the carpet into the plywood/fiberglass (not into the hose). They hide in the carpet pile. If you have trouble fixing the carpet in place, you could try this as well. However, I have found that if you are careful when you remove the original tubing and only peel back as little carpet as you need for access, you won't need to do this.

If the fuel smell won't go away after this repair, you may be dealing with the very sad (and expensive) proposition of a rusted fuel tank. But always try the cheaper fix first and pray for good results.

Back to top of document