My wife has an '03 Golf CL 2L 5 spd.

I installed an aftermarket remote starter (Autostart)
Being a standard, one has to put it in ready mode before leaving the car (shift toneutral, set the parking brake, press the start button on the remote, turn off the key, exit the car and press the lock button on the remote. this locks the doors and turns the engine off.)
This works but the problem I have not been able to resolve is after the car sits for a period of time (overnight or all day) it will only crank and won't start. There seems to be nothing wrong with the remote unit.
I thought it might have something to do with the fuel pump primer function (when the driver's door is opened, the fuel pump runs for a few secs)

Has anyone any experience with this?

Any insight would be greatly appreciated.