Gasoline with ethanol is very corrosive and our tanks are 23 years old. I have 88 Turbo myself. They are very nice and Bosch CIS K-Jetronic injection system is pretty reliable, BUT this system is v. sensitive to contamination and pressure interruptions.
1. Find out how to safely jack up and support the Esprit (LotusEspritWorld.com)
2. Lift the rear of the car, [always use solid 4-legged or round base (NEVER tri-pod type) stands under the rr knuckles].
3. Remove the plastic underbelly pan
4. At the passenger side, under the tank, you will see your primary (black) and secondary(bright aluminum, toward the front) pumps, accumulator (green) and fuel filter (behind the pumps). There is a round 3-3.5" round hole in the fiberglass body, just under the tank. You will see the head of the fuel tank plug (13mm socket).
5. Get a helper to turn the ignition key on.
Lay down under the pumps and listen useing mechanic's ststoscope. Slight humming/buzzing=good pump. Grinding noise or no noise at all=bad pump.
Usually the primary pump sucks the rust from the tank and craps out.
I had to rebuild the black (primary)pump.
Also, the filter was full of this fine rust "soup". It has to be replaced with Purolator F64857 (for SAAB 900 Turbo) or Bosch.
Look for any leaks from the back of the accumulator=bad diaphragm. If you see even a single drop, you'll need a new accumulator.
Before you disconnect any pumps you have to drain and flush the tanks and install a pre-filter BEFORE the primary pump. Lotus engineers screwed-up royally. They put the filter after the secondary pump, in front of the accumulator. Pumps are not protected against grit and rust from the tanks.
5. Get a helper, couple 5 gal clean buckets and 3-4 smaller (2-3gal) buckets and open the plug. Beware! Gas and sludge will come fast at you! Rotate buckets.
During this operation the battery must be disconnected and you must not have any live extension cords on the floor. Use long kitchen/cleaning gloves, use only flashlights and not hand held inspection lights=safety first!
6.De-sediment gas -let it stand for 15 minutes. Strain it.
Fill up 2.5-3 gal gas can which has a wide throat and sizable spigot.
7. Place a large container under the open plug at the right tank and rapidly dump the whole can of gas into the LEFT tank. Repeat until gas looks like it supposed to look-almost clear.
8. Repeat the same at least once pouring gas into the RH tank.
9. Close the plug and loosen the cross pipe between the tanks. dump couple cansinj each tank to drive the grit from the pipe.
10. Do not fill the tanks, leave them dry for the time you'll be working on the pumps, filters,ect.
Remember, this is a temporary measure. Once tanks start rusting, you have to repeat this procedure every year. Never store your car over the winter with tank full of gas containing ethanol. It will speed up the corrosion process!
Here is the list of ethanol free gas stations: Ethanol-free gas stations in MD
Find one close to you and always store car for winter withtank full of "good" non-ethanol gas.