Help, 3 L V6 Shogun 1992, having difficulties starting in the morning or if it has been left to long, this is a duel fuel conversion but I don't believe this has any bearing on it. The car will fire streight away and run for about 5 secs and then cut out, and will not restart, after turning the starter over and over for about 25 - 30 secs it will fire again and keep going. To me it sounds like the fuel is running back in to the tank when left for a long period, i.e overnight, and the car will fire using the fuel in the injector rails. Thankfully, if you get it right, you can flick the car streight over on to gas and therfore avoiding the issue, once this has been run for a few minutes all is fine again on petrol....

Is there a one way valve somewhere along the fuel line,, filter or even in the pump ???