Golf GTi Mk1 Cab Starting Problem

[Willdub]

I've got an F reg MK1 Golf Cab, 1.8 GTi. It starts up from cold perfectly but when you take it for a drive, leave it parked up for awhile and come back to it, it struggles to start. So far it has eventually started after several turns of the key but I am reluctant to take it on long journeys or on stop start trips in case it won't kick up.

It has had many new parts including a head gasket, thermostat, timing belt, water pump, fuel pump, fuel pipe, alternator, spark plugs and injectors. Also, the battery is fine and fully charged, and there is plenty of fuel in the tank.

Thanks

[raferackstraw]

accumulator, small cylinder next to fuel pump under car, this has a one way valve that fails after a while, you need to get a test guage on the injection system to fully diagnose, accumulator keeps pressure in the system for hot starting, if the one way valve fails it allows pressure to drop and as the engine is still warm, you dont get the assistance of the cold start injector.
hence starts fine cold cos of cold start injector, hard to start warm because of loss of system pressure

[Willdub]

Thanks, that's really helpful. I will investigate further