4.4 LPG KEEPS CUTTING OUT

[swipe]

Guys need some help got a problem on my mrs 4.4 for some reason its cuts out every now and then, it takes a few trys to get it to restart and there's no telltale sign when its going to cut out.
I have had this happen on both petrol and gas and can't figure out why, I've run a BMW 1.4 scanner through it and it never shows anything that I would think would be the cause for it to cut out.
Was thinking it could be an air leak or bad MAF but when it does start it runs fine even after it has cut out.
Also each time its cut out if I push the black connector back into the pipe shown in the photo it seems to restart does anyone know what this pipe do?

[IanP]

From here it looks like a flexible fuel pipe where it connects onto the solid pipes but it is difficult to make out. If it is, cant tell if its the supply or return

[swipe]

Think it's cutting out on petrol and the it idles around 400-500 rpm, not sure what's causing it to idle so low?

[Ubatoid]

Before you try and diagnose a problem like this you need to isolate the petrol and LPG systems. Get it running correct on petrol first. I would be checking the fuel pressure first and at the same time make sure all connections are clean and tight especially those to the main ECU.

[g60renshaw]

Is it definitely when it's on petrol, as if it's doing it on LPG it sounds like the filters are getting blocked.

[swipe]

It only does it on petrol, just had a call from the Indy an they could only get it to cut out once. The rpm seems to have improved for some reason but they couldn't find out the problem. Have given me a number for a specialist so will have to drop it off to him soon. It's really strange as it's very intermittent and there are no warnings that it's going to stall.