something like this happened to a local member, and it turned out to be a o-ring.
"So i took the car Apex Specialized to find the problem. $600 dollar later the problem was a cracked rubber O-ring. the O-ring was around the Fuel filter. This cracked O-Ring basically killed the fuel pressure. When I checked the Fuel Pressure i thought it was enough but apparently i was wrong. the entire upper part had to be replaced and now she is running fine. It hurts cause this is something i could have replaced myself but i did not know what was wrong. here is a picture of what went wrong...."