I have some information which, perhaps, is related.
I've had bucking (that burping/bucking at 55+mph when feathering the throttle) that's increased recently. When it didn't go away with a filter change and hose-clamp tightening I tried the "lift/fuel-pump from a '95 Suburban diesel" ahead of the filter approach in an attempt to see if I couldn't get rid of air entering the system. Assuming it was being sucked in somewhere around the filter assembly/puck/filter gaskets/etc.
After getting the pump installed in-line just before the filter input, it got worse... not better. I checked and re-tightened everything - still horrible. Lots of air to bleed every time I shut it off. "Large fuel leak" fault codes... (new one - hadn't seen it before). Went into limp mode on long pulls, died after WOT emptied the filter, long weak acceleration from a dead stop, long cranking times even when I let the lift pump run and prime before cranking it over.
So - I pulled the pump (mounted in the engine compartment for convenience) and put everything back to stock.
Starts immediately, runs fine, burping/bumping is a small as it's ever been (barely detectable now). No codes.
So, my guess at this point is that the air is being introduced either by the in-tank pickup or the rubber hoses that transition from the tank to the steel lines that bring the fuel up front... surmising that the lift pump increased the vacuum on the lines and actually sucked more air into the system.
An alternative I consider less likely but not impossible is that the lift-pump doesn't flow as much as the CP3 pulls, and I increased suction/leakage at the filter assy and just made the leaks there worse.
What are the odds that we're all fighting something like this (leaks back at the tank) as a partial contributor to our air-in-system woes?
Mark
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ATXKJ wrote:
I was trying to distinguish between 2 levels of fixes
Racor only head - this is for the people who have constant problems the dealer can't fix -those who have to bleed the filter head every day or every week - I think this is a minimum for those folks.
However due to the nature of a vacuum system and air in fuel and intermittant fuel problem I expect that there will be long term issues - probably fuel pump replacements around 100,000 miles or so - I think the system is just a bad design therefore I'd like to look for a second step for those who intend to keep their CRD until the wheels fall off.
Target 500,000+ miles with nothing but scheduled maintenance
That's where I'm looking for Lift pump, pre and final filter , some way to vent air and return lines with coolers.
Racor is an option - but so are Cummins and Duramax solutions