_Matt_ 26 Posted July 5, 2018 That does sound more like a fuelling problem Rob. The way I understand it is the FPR is supposed to maintain rail pressure for (days?) so when you start from cold there's some fuel in the lines to get it going and then pumped fuel from the tank takes over. Does it start quickly but just splutter? i.e. not crank and crank? Maybe check the state of the fuel filter and replace in case of a infrequent blockage? Quote Share this post Link to post Share on other sites
robrado974 1 Posted July 5, 2018 Yes it’s starts straight away , it doesn’t happen all the time . It cant be the injectors, the performance would be down . I’ve got a spare brand new filter so I could try that . Quote Share this post Link to post Share on other sites
fla 9 Posted August 20, 2018 I was thinking of fitting a pressure gauge on the fuel rail (on the bleed nozzle). Does anyone have any experience of this at all? Also, perhaps a long shot but if there is a spark and fuel going to the rail, could it be that the ecu is not allowing the injectors to open (for whatever reason)? Quote Share this post Link to post Share on other sites
fendervg 30 Posted August 20, 2018 Yep, I've tested the pressure at the rail using the small bleed nipple on the left and a rotary gauge. You should see 3.5 bar with the engine running at idle and 4 bar with the vacuum hose on the right of the FPR disconnected. When left standing, it should settle gradually but you should still have 3+ bar after several hours. A few of us had these types of problems and ended up suspecting a leak back down the feed pipe and valve at the pump in the tank - this ended up with us fitting a small non-return valve there and this solved the problems. There was even some evidence that there as an official VW part for this fix with some pictures floating around. I'll do a search of my old threads and post a link if I find anything. Quote Share this post Link to post Share on other sites
