Hi Touristas.
I think you have an ETV-MSE. This model runs from aprox 1988 to 1994. A well known problem with this is the rubberhose inside the tank. When this hose gets old it softens, and when you lift AND only when you lift, the hose get flat and oil can't flow. You can check the oil after lifting. If you see a lot of small bubles (air) in oil, the pump get no oil. It is also a litle noisy during lifting. Replace hose and it may run proberly.
Best regards, Max