intermittent sputtering / won't start issue - please advise

[chuckk_]

Hello everyone. I've been having an issue over the weekend with some intermittent sputtering, and it's only gotten worse. Now it's killing the engine.
It started Friday night about 8 hours / 20 miles after I filled the tank about 3/4 full. The next day, knowing I was overdue for an oil/fluid change and thinking I might be low on coolant, I drove the car about 3 miles to the quick lube place. It was fine the whole way there. On the way out, it started again.
On the way home, I saw my usual mechanic in his shop taking care of paperwork. He came out, saw no codes on his reader. Reved the engine in neutral and got it to backfire a few times. He thought it was the fuel intake regulator. I got it home fine about a mile with some sputtering.
I let my car sit for about an hour. Started it up again. No problems until about 20 miles on the highway. Same sputtering when I was accelerating to pass someone. Drove another 100 miles to my dad's house on cruise, no real issues.
Dad replaced the fuel intake regulator. Took it for a test drive. About 15-20 miles later, same issue.
Let the car sit overnight. Today, I tried to drive it the 120 miles home.
No issues until I took a pit stop at the half way point. Started going again and the sputtering was present. I drove it about 15 miles sputtering before it stalled out while rolling on the highway. Rolled down a freeway ramp. Let it sit for about 2 hours. I was down to 1/4 tank, so I filled it up at this point thinking it might be bad fuel, and bought a can of some $25 fuel additive crap thinking it might help.
Drove about 30 more miles and it sputtered more before it died rolling in city traffic about 10 miles before I got home.
Sat for another hour, started, drove about 3 more miles sputtering the whole way, and it died again. Pushed it into a parking lot, and now here I am posting this while I drink a beer at a neighborhood bar to relieve the stress of a 2-hour drive that has taken my whole day and I'm not even home yet.

Now,
In the interim after it dies, burt before it'll start again, it cranks and cranks but won't turn over. It kinda acts like it's flooded.
I seemingly still have fuel pressure in the engine. The bleed valve sprays gas with high pressure just fine.
No SES light. No codes.
Not sure.

Does this sound like a MAF issue like in this post?
Bad gas?
Crap/rust in the gas tank clogging the mesh sock on the fuel sending unit?
A bad fuel sending unit all together?
Or, something else?

Whatever it is, it's obviously getting worse. I had the fuel filter replaced probably about 5,000 miles ago. If it's the fuel sending unit, I can order that part and do that myself. But I don't have a hoist. Nor do I have all kinds of cash to toss at my mechanic to drain the gas, drop the tank, flush the fuel system, or keep changing parts out to see what's going on.

I'm about to head to the car. I'm gonna disconnect the MAF just to see if anything changes. I'll report back, but any thoughts are appreciated.

[chuckk_]

Update: As I sit on the side of the road again, 5 miles from where I just left, I can tell you -- It's not the MAF.

[Archon]

Any issues with the tach when this occurs? You could have an intermittent crank shaft position sensor. It often goes without setting a code, and can act up when it gets hot. When the car won't start, try pouring some cold water on it and see if it starts.

[imidazol97]

Update: As I sit on the side of the road again, 5 miles from where I just left, I can tell you -- It's not the MAF.

The fuel pump could be lowering pressure after it heats up. But this means putting on a pressure gauge and driving with it taped to the windshield and seeing if your pressure is dropping when the car acts up.

Good news: the fuel pump can be replaced through the access hole in the trunk floor.

The EGR valve started sticking occasionally on my 98. It caused a rolling idle miss when I'd come to idle after the car started to warm up. I'd rev it up when I caught it before it died and it would be okay. I cleaned the shaft inside where it goes up into the top part of the EGR. It seemed to be sticking slightly open rather than being held open by particles on the pintle where the gas flow goes through and the particles keeping it open.