The third-generation Mazda RX7 (FD3S) suffers from fuel starvation issues when driven aggressively, especially on vehicles with R-compound tires. This problem is caused by particularly wide and shallow fuel tank with an off-center pump location which is offset to the driver’s side. Under hard acceleration to the left, the fuel in the tank is forced away from the pump causing air to be introduced into the fuel lines. This can occur after less than ½ of the gas in the tank is consumed. With rotary engines fuel starvation can cause cut-outs or lean conditions that will rapidly lead to engine failure.
Mazda made several attempts to reduce the possibility of starvation. The factory fuel pump and inlet filter sit within a plastic surge bucket. This bucket is a gravity-fed (hydrostatic) system that fills with fuel under normal circumstances but retains a small amount of fuel when the rest flows away from the bucket under longitudinal or lateral acceleration.
In the 1994 model year, Mazda added three tab slots around the bucket, designed to retain a cover to stop fuel from spilling over the sides of the bucket. Curiously, Mazda did not actually add the cover until the 1995 model year. But even this additional cover is not particularly effective due to the poor fit around the fuel pump which allows a significant amount of fuel to spill out during hard driving.