Well took the tank down again for the 3rd time and hooked the old pump up to the connector dangling in the air. It read F to E just fine. Tried the new pump it also read F to E. Put new pump back in tank which was about half full eyeballing it. I slid it under the truck and hooked the connector up and the dang thing read 3/4. So slide it back out and emptied the tank then slide it back under there and it read empty. So that's better than when the tank was empty and the gauge would read half. So I strapped the tank back in the truck. Checked gauge, still reading empty, put 2 gallons in to start and it read 1/8 with 2 gallons and I'm thinking son of bi*** 26/8 is 3.25 so already reading a bit off. Drive down to the gas station and put 4.5 gallons in to make 6.5 or 1/4 of 26 gal and the thing just reads under 1/2 but more than 3/8. So the darn thing is still off but better than what it was. I'll try resetting the computer at some point. But I'm pretty fed up with it and might just bring it in to a shop to get the gauge reading correctly and make it their problem to deal with. As much as I hate to say that.

 

Been a long time so to sum up quick. Put a new fuel pump in this truck about a year ago and when the tank was empty the gauge would read it was half full. Returned that pump under warranty and the new pump had the same issue but instead of half a tank it was 3/8 of a tank off. 1999 1500 5.9L Pump has arrows to line up with [ ] lines on tank it self.

I recently rebuilt my transfer case in this old beast. While I had the drive shaft out I figured I would pull the pump down again and do some DIA on this fuel pump to gauge misreading issue. This time I just decided to bend the float arm to read correctly. I emptied tank (maybe had a gallon left in it after emptying) and put in two gallons. Pump was reading below red line empty. So I added one more gallon to see if it would move from there. It did move to just under an 1/8 of a tank fuel light still on. SO figured that's close enough for me versus the old 3/8 of a tank off reading when the tank was actually empty. All said and done I start driving to town(15 mile trip) tested out 4x4(working great now) and about 5 miles down the flat road with just the 3 gallons of fuel she starts sputtering and rpms dropping out and just dies on me. Dad brought me 5 gallons, added that and the just below 1/8 gauge jumped to 1/2 tank. Its a 26 gal tank and at this point it would have 8 gallons. Started back up just fine finished driving to town. Had to go up a very steep hill so I started at the bottom at 80 Mph because I figured fuel would pool at back of tank and she would cut out on hill. Sure enough it started to sputter out just at the top of the hill but had enough speed to make it up. Never died. Got to town and put in 21.020 gallons of fuel.

So my question is, why did it die out with 3 gallons of fuel? Is there something I am missing here? Are these pumps not able to suck off the very bottom of the tank and need to have a few gallons in at all times even on E? I think at this point my Spectra pump is just no good. Another issue its having now, is after idling for about 3 minutes everything good the idle will start to sound weird and it will eventually just die like it ran out of fuel. Never had this issue before. Can air get trapped in the fuel line causing this? Or again do I just have a garbage fuel pump.

Thanks for the feedback you guys are great!

 

Oh I should mention about two years ago I rebuilt the engine on this truck with new Edelbrock heads and the FI air gap from Hughes engine new pick up coil on distributor and stuff like that. Truck has always ran top notch since rebuild and I did have a shop check it over as it was my first rebuild completely self taught. I was a little nervous it was just going to explode at any moment and wanted some outside assurance.

 

I believe you just have a garbage fuel pump. I am having the sense problem though. Swapped an OEM fuel pump that worked and the sending unit doesn't read at all. I plan on buying Delphi as they were the supplier to Dodge. I know personally my old pump had an issue where (no matter how full it was) the harder you ordered the gas the quicker the gauge went to E. Let off and it would go back to the correct reading. My old pump also would suck all but about a half of gallon out of the tank.

 

Yeah, what brand pump are you putting in there? Air-Tex??

 

Who me or the OP? OP said Spectra

 

I don't think they are any better than Air-Tex..... Denso, or Delphi please.

 

Mine was OEM lol. Every brand has their problems but when I buy a new one I will buy Delphi