1983 245DL. Vehicle runs like new but for one niggling problem: Hot, cold or in between, first turn of the key anything less than five seconds and the car does not start. After releasing the key the car then starts with just a brief flick of the starter! Turn it off, it fires again instantly with barely a touch of the key. However if it sits for anything over ten minutes the same routine applies. I'm thinking this is the fuel pump check valve, anybody want to verify based on the evidence? Injectors are semi-new and spray evenly...and seem to shut off cleanly. Also it runs too well to indicate any injector problems...super low smog readings at recent test too.

Thx,

DS