Hello all. I've replaced return lines, all the glow plugs, pretty much anything fuel related from filter housing back to tank, including lift pump, and it still takes at least two 5-10 second crank tries to get started...it acts like it's still losing prime somewhere but like I said, I've replaced it all. It will start right up after it's been running for a while though. Is there a check valve or something that I've missed?? Is it time to look for a new IP?? Thanks in advance!