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I have a thread on another forum, and m1973m's posts there, led me 'here'.Basically, it boils down to this:On Key-on, I bump the starter. With a fuel pressure gauge on the system, the lift pump (prev. owner replaced the lift pump (with what appears to be an Airtex E7153 or replica), as well as added a [crap] Mr. Gasket #12D inline pump (rated at 5-7psi, 35gph) back by the tank. The LP kicks on, and the pressure slowly climbs from zero - ~19psi. Once the LP kicks off, the pressure immediately falls to ~5-6psi. If I sit anw watch it for a few seconds, it'll bleed off to zero PSI.If I repeat, and as soon as it hits 19psi on prime, if I start it, it will fall to zero in about 5-10 secs. I'm wondering if the LP isn't kicking back on after startup. The relay in the fusebox is tripping on, and I've swapped that relay for a known-good one, as well, with no change in results. Is there a way to 'hot-fire' or 'jumper' the LP for testing purposes, to ensure it's pumping when the truck is running? The 'aftermarket' #12D back in the rear of the truck is worthless, IMO. I have a big inline Bosch pump in the garage, but it flows 255LPH and capable of anywhere between 30-90PSI head pressure, depending on the regulator of the system (the pump itself isn't regulated) and I fear that it may be too much pressure for the VP44.I'm not opposed to buying a FASS or AD or whatever, but I'd rather try all other means to ensure that fuel pressure feeding the VP44 is the problem, prior to dropping 4-600$ on another unit.Also, why would some inline pumps state "not for diesel fuel".. Is it the gasket material or something in them that can't handle the fuel's chemical compound?At any rate, let me know your thoughts on the maximum fuel pressure allowed to the inlet of the vp44, as well as ideas to test functionality of the current (new) lift pump in question.Regards,Rick

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No idea. At any rate, I drove it into work today. It seemed to run fine. It is funny, however, that a 245/500 Cummins can seem so "weak feeling" after driving my P-pumped truck for so long :cookoo: The throttle response is going to take some getting used to, that's for sure, as it's nowhere near as responsive as the '96. But all in all, it seems pretty decent. Especially considering how 'cheap' I got the truck for, combined with how much I have in it. :tongue:Now, I need to work on the weird-feeling steering. Is seems tight, kinda, almost draggy. with a vague 'return-to-center' after cornering.. But I'll make another thread for that.thanks for all of you guys' help and advice with this issue! I greatly appreciate it!