What's my problem?

First a little back story. My fuel pump went out about a month ago while I was driving on the highway. Truck just shut down, steering wheel locked up. It would turn over but wouldn't start. Took it to the shop they said it was the fuel pump and replaced it.

2 weeks later I go back to the shop. The 3 times I had put gas in the truck since the new pump the needle wouldn't move once I would finish putting gas in. Instead it would slowly go up over the next 10-15 min. Then, just before I decided to take it back to the shop I got gas and the needle didn't move at all for 15 min, then I looked down and it had gone up in the blink of an eye. Take it to the shop and they determine that it was a defective pump. They change it free of charge (great guys and great service).

Since then though I have only ever had a problem when I fill up completely. When I do fill up completely the needle doesn't go up all the way but more about 3/4 of the way and then slowly rises while driving (I found this all out while driving from NJ to KY and back).

I filled up last night before my drive out to Ohio today and the needle did the same thing. The gas station is around the block from my house so when I got home I turned the truck off and back on and the needle went all the way up no problem.

Fast forward to today, I stop to get gas after driving for about 5 hours. I have 92 miles left in the tank according to the EVIC. I pull off the highway into the gas station and as I come to a stop my idle starts pulsing going really low and almost stalling out. I fill up on gas (well almost, damn pumps stop at $100 lol) I turn the truck back on and the needle doesnt move and the EVIC still reads 92 miles left. I know I put 25 gallons in so I know I have gas and the idle is still pulsing weird. Everything drives though so I get on my way.

About an hour away from my destination the truck shuts off and the steering wheel locks up, just like it did when the fuel pump failed. I get to the shoulder, turn off the truck. Just before I turn it back on I turn the key half way to see if everything is working. I notice the light in the bottom right corner (the one that comes on when the TB isn't hooked up all the way). I saw it for just a sec as I tried to start the truck. The truck starts as if there is no problem. The gas needle also go all the way where its supposed to and the EVIC now reads like 300 miles left.

Can anyone tell me what might be wrong? I think I may have some sludge stopping the pump from reading properly so I was going to run seafoam in the tank to maybe clean it out. Could that be my problem? Or is there a chance I got 2 defective pumps in a row?

Sorry for the long winded post...

I also posted this in another forum so if you've seen it there, sorry, I'm just trying to figure it out since I won't be home for a few months

DO NOT USE SEAFOAM. The only way to get rid of sludge in the tank is to drop the tank and clean it out manually. All that seafoam will do is suspend the sludge and over time it WILL separate out again causing problems once again. Sounds like something is not connected correctly or even another faulty pump. Go to the dealership, get a NEW pump, and then take that to the shop that did the work and have them install the new pump.

I can't get back to the shop that did the work. I'm in Ohio for the next few months. I'll either have to do it myself or find another shop.

How difficult is dropping the tank and cleaning it out/replacing the pump?

It could be that "topping off" the tank is causing a problem with your fuel evap control system.

Dropping the tank is easy as long as it is empty or nearly empty. The pump assembly is on the top and once the tank is out real easy to remove and replace. If you do have sludge in it, then the best time to clean it out is with the tank off the truck. Depending if you have the plastic or steel tank will make it a bit more difficult. The plastic one weighs nearly nothing, while the metal one can be 100 lbs or more. Use a floor jack under the steel tank and just in case do the same with the plastic one. You do not want to mes up the wires and hoses going from the tank.

While I cant rule out another faulty pump, it happens, from your description I would also look into chafed wires or moisture causing a short somewhere. That's a possibility for two different pumps not reporting correct fuel levels.

The rough idle and near stalls is probably something different. I agree with MegaMouse on the SeaFoam thing. (Kinda) It's better to drop the tank and clean by hand. I have a 2004 as well and just this week had to change the fuel pump, but the inside of my tank was spotless.

The fuel pump needs to be positioned carefully so the fuel level float arm isn't dragging on the tank causing a delay in reading properly. Becareful not to run out of gas, watch your mileage and fuel up more often until you can drop the tank. I siphoned gas out of the tank using a hose before dropping it. This surprised me somewhat because I didn't think it could be done anymore. Good luck..

I haven't had a problem since the truck died yesterday. No idle problems no anything else. Truck runs normal. Not sure what to do...

I guess I'll check the lines underneath when I change the oil later this week.

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Next time it acts up maybe try checking the evap/charcoal canister in front of the gas tank. If there is any gas in the canister or in the tube coming from the top of the tank it could be creating a vacuum inside the tank since this is where fresh air is drawn it to replace the fuel as it it used up.

The poor idling when the tank was near empty could have been caused by the pump trying to suck fuel out of the tank under vacuum. Maybe this could have caused your fuel pump to fail the first time? Also, this may seem far fetched but if the tank itself is collapsing/deforming under vacuum could this be causing your float to not read correctly? This condition would not give you any codes and might explain why it stalls one minute but runs fine the next. Might be worth checking since you wouldn't have to drop the tank.