Trx420 running issue!?!??!

Hi all, i am new to all this internet forum stuff so bear with me lol! Basically i have had my trx 420 for about 6/8 months now and i absolutely love it as a useable machine around our shoot, although the one thing i am not loving is the random cutting out!! There seems to be no pattern or cause as to when or why the machine cuts out but when it does it all points to a fuelling issue?!?! But after a new fuel pump and filters the problem is still there!!! After putting a voltmeter on the plug to the fuel pump it seems that the voltage is very inconsistent, it seems that if the voltage drops below 10ish its not enough to run the pump? But what would be causing this to happen at such random moments and why if you leave it for around five minutes (sometimes more sometimes less) it starts again and may not cut out for minutes, hours or even days? Any ideas or help would be much appreciated as its getting worse and my patience with it grows shorter each time it stops working!!!