[special-K]

Your '93 should be mechanical injection, DBII pump. I never had that kind of problem with fuel, but I've had lagging and stalling that was hard to figure out on a '92, same set-up. I tried everything, I figured. Maybe a year before the issue I had run new fuel lines, dropped tank, cleaned that up and rustproofed it. While I was at it I replaced the sending unit/pickup.

It was really cold, like single digit, so I suspected gelling. I rescue treated it and all seemed fine, but not for long. It might be ok for a couple days. It seemed pressurizing the tank would get it going again. I suspected some freak debris issue. Like some a-hole stuffed trash in my tank.

Tank and fuel looked perfect. I cut the sock off the pickup and look, my buddy looks, looks fine, looks new. Cut and stretched flat I blew 120 psi on it with my hand on the other side. I couldn't feel any air, only back on the hand holding the blow tip.

We sure were baffled on that, but there was no doubt there is where the problem was. One of those can tell you what but can't tell you why kind of things. Truck ran fine for a long time after replacing the unit.

That was a crap replacement part issue, I suppose. But it does go to show how funny that diesel can act. Might help your thoughts some on your problem