PROBLEM SOLVED
Since I'm not getting any meaningful response over on the 4th gen forum and most of true diehard gearheads hang out in the All Motor forum, I'd appreciate any feedback you guys can give me based upon firsthand experience:
http://forums.maxima.org/showthread....49#post5447249
Thanx much,
Curt

 

Happens to me any time the fuel level in my tank is low. Even a tad hard to start at times. Get used to it. Fill up, problem solved.

 

i agree, same thing happens with me when i have to fill up around 15.5 and more gallons of fuel. But i have a walbro190. When I had the stock pump I could run it down to the last 1.5 gallons and it wouldnt starve. But with this pump at ~3.5gallons remaining if i go above say 4500rpm it just feels as if i hit a rev limiter, lol.

Just dont let it get that low and you're good to go. I try to fill up soon after the gauge needle goes under the last 1/4 mark. If I run it into the E it will still drive but I'd have to really grandma it

 

Keep in mind that this is a relatively recent and definitely noticable change, wasn't something that developed slowly over time. So, as soon as we have a warm day and I'm down around 1/4 tank, I'm getting in there to have a look.

 

Well have it but, it's probably a wasted effort. Do you know what you're looking for?

A simple FP test should suffice to diagnose any problems.

One thing you'll gain in that warm afternoon is more experience in the fuel pump area of the car. So. it's not an entirely wasted effort.

 

Well, only a couple of us were even close to the cause of the problem. I finally had a nice-weather day with only a couple of gallons left in the tank, so I opened it up to have a look. The strainer bag (made of gauze-like material) that basically sits in the bottom of the tank was crudded up with a sediment substance that looked like clay mud. I shot half a can of carb cleaner on it and it disappeared. Then I reinstalled the fuel pump. Simple as that.
Proof is in the testing: with the tank (as I said) close to empty, on my way to the gas station (and with 415 miles on the trip odometer since the last fill-up), I floored it in first right up to the (JWT) 7200 RPM redline. Absolutely no hesitancy or bucking as the car had been doing previously. When I topped off the tank it took 16.0 gallons (that works out to 25.9 mpg for all you math majors). And if the old butt dyno means anything, the car seems to run a little stronger whenever I get on it.
Moral of the story: my '96 Max has 128K miles on it, and I cannot think of any reason why the sediment I found should be in any way unique to my car. Any of you guys with cars over 100K miles might want to spend an hour checking this out. Chalk up one for the home team, and NmexMAX, you whiffed! I'm tempted to comment about those 16 thousand-plus posts of yours, but I'll pass.

 

oh wow Curt, I didnt think of this. Why would you have that crap in your tank to begin with though? Bad gas over the years building sediment on the strainer?

I had 135k miles when I upgraded to a Walbro 190, and my strainer had a few specs of what looked like sand, and there were some tiny metallic flakes at the bottom of the tank (wtfmate?)

 

That makes perfect sense about the bag being clogged up and prevent fuel delivery when needed. Actually, additionally, I think a full tank versus low fuel has to do with this bad fuel delivery also. Because when you have a full tank, the lower part of the tank where the "filter bag" sat experiences a higher hydrostatic pressure, meaning the "fuel front" is readily pushed into the gauze for fuel pump to ingest. When your fuel runs relatively low, hydrostic pressure decreases, so that "fuel front" is probably lingering at the gauze and only the fuel pump suction is acting on bringing the fuel into the pump. Since the gauze is substantially clogged up like that, you'd get bad delivery to the engine at low fuel. It's like scuba diving, the lower you'd go, the more you feel being squeezed by the water, in this case, you are the filter gauze bag, no pun intended. LOL.

I'd also replace the fuel filter on the firewall, too. It's only 10 bucks and will make sure fuel filter won't be the one to act up later.

-Peter-