Car will not hold an idle; dies. Have recently replaced the distributor, water pump, timing belt and valve gover gasket.
None of the things you replaced have a lot to do with idling. Usually, the car would either not get enough fuel or not enough air.
We don’t know what age or make your car is, but on old carbureted units there is an idle adjustment screw which allows a change in idling speed. On computer controlled cars with fuel injection, you need to see a mechanic and have him investigate what the problem is first.