Has anyone experienced a similar problem to this,it’s driving me crazy.when I start it up I get exactly 8 seconds of it running as sweet as a nut but then it goes into limp mode and seems to lose boost and won’t let me rev past 1500rpm.this can be overridden by flicking the ignition key back 1 place and then forward again which will allow another 8 seconds and so on.the annoying thing is that the fault disappeared for 4 weeks and then reappeared again when I needed the truck the most.tried the usual suspects ie fuel filter etc but everything seems fine.totally baffled.it might sound daft but could the exhaust brake be kicking in?