I have what is now a high mileage 02 4x4 w/4.0 engine. The original electric fuel pump went out at 180K on its own. I'm coming up on 360K now and was just wondering how many miles when all you other users had to replace their first fuel pump.

 

'03 with over 460,000 km/275,000 mi - still on original fuel pump.

I've always tried to not let the gas get below 1/2 tank - not only does it help prevent excess condensation/moisture build up in the tank, but I've also heard that a high gas level also helps keep the fuel pump cool (which kind of makes sense to me).

Don't know if that's necessarily a factor in fuel pump longevity, but it certainly hasn't hurt, from my experience.

 

The note about keeping the fuel tank full is what I was told too after my first failure. I've been trying to keep the fuel up and hope it plays out to be true. I was concerned because I'm coming up on my second 180K.
The first time it failed I was up in the mountains 30 miles from the nearest town. I nursed it back to town all that way. Since it was mostly downhill to the town the engine fuel fed on gravity. Oh there were a few hill sections in between though. She coughed and sputtered until I hit the top. The road was shared by loggers too which made it a little more interesting to say the least.

 

Doesn't cost any more to keep the tank as full as possible - just "costs it sooner".

Moisture in the tank (which, if excessive, eventually will find its way into the lines) is always problematic, especially in freezing temperatures - nothing like a "no-start" due to frozen lines to mess up your day - especially if it takes days to thaw - always use gas line de-icer in winter - maybe not you guys down south, but anywhere you get snow - also, it's hard on the pump if it running and nothing is going through.

Change the fuel filter regularly - any obstructions/constrictions means the pump is working harder than it should and will burn out quicker.

In cases of what looks like pump failure, check the underhood relay (I've had issues with this one), the fuel cut-off switch/inertial switch, wiring and connectors (especially the main connector on the underside of the truck, under the driver's side/seat, kind of next to the transfer case on a 4x4 - 4x2 same place, just no transfer case) for corrosion - that's a show stopper for sure.

Fuel pumps are funny - can last the life of the vehicle or just go after so many miles - good for you to keep your eye on it, but no guarantee that because it failed before at that mileage that it will again.

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P.S. Keep your membership in CAA (AAA in the States) current in case you need a tow in case it does fail despite everything