A fuel tank is made by a process comprising injection molding a polyketone polymer into one or more parts of the tank and joining the parts of the tank together. The polyketone polymer is a copolymer of repeating units of the formula --CO--(CH.sub.2 --CH.sub.2 --)-- and repeating units of the general formula --CO--(G)--, where G is a moiety originating from an olefinically unsaturated compound of at least 3 carbon atoms and the molar ratio of --CO--(G)-- to --CO--(CH.sub.2 --CH.sub.2 --)-- is between 0.02 and 0.15, and the copolymer has a limiting viscosity number, measured in m-cresol at 60.degree. C., of between 1.4 and 2.0 dl/g; and said process.

In a fuel pump inlet chamber assembly having a communication passage which allows ejection of fuel from the fuel pump inlet chamber to the remaining part of the fuel tank only at a limited flow rate so that any short-term change in the fuel level due to the motion of the fuel inside the tank may not substantially affect the availability of fuel inside the fuel pump inlet chamber, the fuel pump is conveniently interposed in the interface between these two parts, thereby not only simplifying the assembling work but also allowing easy access to the fuel pump for servicing purpose. This takes advantage of the fact that the fuel pump inlet chamber is normally made of molded plastic material, and is required to be constructed from two pieces, i.e., the main body and the lid member. Thus, the fuel pump inlet chamber assembly can be made simple in structure and easy and economical to fabricate while allowing easy access to the fuel pump.

A fuel tank comprises a shell made by assembling together at least two tank portions each made by molding a thermoplastic material and, when assembled together, defining the inside surface of the tank. The tank has a fuel pump fixed to its inside surface before the tank portions are assembled together.