300TDi vacuum-side fuel line leak
**Skip to BOTTOM LINE if you're not into narrative and just want to see what the issue is, AFAIK**
Right after the movers boxed up my spare parts bin, I headed to the in-laws for the evening. On I-66 I notice that (once traffic allows me to do so) I cannot go over 65, and EGT isn't even hitting 900 (normally will get up near 1200 if I floor it for a sustained period).
Once home I notice the throttle cable has worked its way loose, so I tighten it, hoping that the problem was just failure to move the injector pump arm fully.
No such luck. This a.m. could barely go 45, with power loss occurring in higher gears. I limped it back to the house, opened the bleeder valve on the fuel filter--nothing. I opened about 5 boxes, found the spare lift pump, and put it on. (pump I took off seemed to be working fine, using the finger-over-the-hole test). Lots of fuel at the bleeder right off the bat, but a quick test drive revealed power loss was still an issue. Once back at house, opened bleeder valve, nothing.
I checked the sedimenter with the engine idling--fuel level in there seems low, and there are bubbles at the top of it. Looks like its pulling bubbles in from the tank side.
I bypassed the sedimenter and tightened the hose clamps that connect the 8mm fuel hose to the rigid lines from the tank and to the lift pump and take it for another spin--seems better, but still producing no squirt at the fuel filter bleeder valve at idle after a drive, so I think the leak is still there.
Lastly, I tightened the compression fittings where the lines meet the tank. . .
***BOTTOM LINE: I apparently have a vacuum leak between the tank and the sedimenter. Obviously putting a 12V pump in after the sedimenter (which is what I've seen recommended for other vacuum leaks) won't help me.
Any thoughts on diagnosis?
Should I just cut the flexible part of the OEM line right by the tank compression fitting and run fuel hose straight from that cut to the sedimenter?