hi I have a 99 dodge ram 2500 with the 5.9 360 in it and a while back the gas gauge stoped working on it. most of the time it stays on empty but often flucuates between full and empty. well last night i change out the fuel pump because i thought that it was the fuel level sending unit but its still doing the same thing. any ideas on what else it could be? also if it helps after i put it in i turned on the key and unplugged and then pulgged the harness to the pump it will go from empty to full. Thanks

 

I have a similar issue with my 99 2500.. I was told the sending unit is in the tank and you need to drop the tank to fix the gauge problem. I that what you did? I have not done that I just fill up when I hit 200 miles and I have not run out yet.. I'm getting 10 mpg..

 

Wiring, or cluster problem.

And you should be getting better than 10mpg.....

 

I was in this EXACT same boat and still am. I found a fix for it for a couple dollars a year ago but like seaham i fill up every 200 miles lol. What i found in the fix was the one of the parts in the sending unit in the fuel tank is made out of a type of polymer (plastic) which over time gas (solvent) eats away. This float will then have the wrong buoyancy and will not float correctly unless it is completely submerged with gas and the non plastic part will still float. So when you fill up you will be full for about 20-40 miles then it will start to read empty. Cheap fix, but labor intensive at least from the info that I've gathered. Anyone ever replaced this and can help a couple people out???

 

Oh and I had 10mpg untill i replaced ignition coil, spark plug wires, spark plug, distributor cap and distributor rotor, ball joints then got an alignment and now im at 17. get your distributor rotor and cap and make sure you route your spark plug wires properly away from headers and not to let them wrap around each other.

 

What kind of wiring /cluster problems r u talking about? i took the insturment cluster out and every thing seemed to be fine. is there any kind of relay thet could have gone bad?

 

yes the fuel pump and sending unit are all one piece You can drop the tank but to me it was just easier to take off the bed because i had an overhead hoist.

 

Hey you, I'd love to get more then 10mpg, I do get 11- 12 mpg on longer trips.. Around town and when I haul wood it's 10..

TheycallmeLaramie, the truck runs great, but I'll look at the items you mentioned and see what shape there in. I'll start with the cap and rotor and go from there. I want to say they were new when I got the truck 2 years ago and I've only put on 6-7000 miles in two years..

hazen, keep us posted on your fix if you find one..

 

Love to see what MPG you get with new rotor and cap. Although you have the 5.9. I have the 5.2 so I doubt youll go up massively higher but cap and rotor should always be changed inless you know when youve done it and its been recent. Its like 40$ and I was losing that almost everytime i filled up LOL. Im sure you know but get the brass distributor cap :P I got accel worked like a charm. new wires and spark plugs help too and its easy when your all the way in the back on the distributor cap