The standard one is adjustable dude
If you look at the the top of the reg in the middle you will see a shiny little cap
If you remove that,you will see a little Allen that will adjust the fuel pressure
But you need to find out what you should run iirmc I may of rung a tuner and asked what I should run on beiges poss could of been 3.5 bar at idle with vac off ( BUT please check this before you adjust it) I think i ran the co on about 3 to 3.5 % but wasn't running loads of boost and was all on on a air fuel gauge when checked ( was on a cvh engine)
I would just plug a ( I plugged in a fez Amal valve ) but set the boost on the act and the dreaded bleed valve lol
Was perfect for me unless you keep playing with it.
That could could be linked as it cannot see the Amal valve
Hope this help