Hesitation or missing on hard acceleration/highway speed

[Feds]

1996 2.8 Royal Exceed

I've been noticing this for a couple of months. On moderate acceleration (i.e., 3/4 throttle), the van seems to hesitate or miss between 2800 and 3200 rpm. With constant throttle application, it loses power then picks back up. The losses of power are less than a second, and once it clears 3200, it is fine until it shifts.

Similarly, when rolling down the highway I get intermittent misses. I have to be going more than 110, or climbing a hill at 110. It just misses a beat, but pretty regularly and repeatably.

I don't see any black smoke out the tail pipe when it does this, so I'm assuming it's starving for fuel. I've done my fuel pump seal, I've change the fuel filter, and this weekend, I tried driving with the fuel cap loose to see if the tank was going under vacuum. None of these things have helped.

Next on the list will be to blow out the fuel line, then maybe new injectors. Beyond that, I'm out of ideas. Anyone have any other suggestions/experience?

[nxski]

Pop off valve on the turbo perhaps? Do you hear a faint hiss when this happens?

[legionnair]

Tps starting to act up