[jetskinjoe]

I have a 94 Ram with the 5.9L gas hog and the fuel gauge just started to have a mind of its own. The tank is 3/4 full and the needle goes up and down, not a little bit either. It goes from full to empty and then the gas light comes on. Anyone else have this happen? Am I gonna have to drop the tank to change the sender?

Also when the tranny is in top gear(auto trans) it seems to lug along, when I downshift the trans it seems to cruise fine but as soon as top gear engages it starts to lug back and forth. Trans rebuild time?

Thanks for any info ahead of time, I have learned alot just by hanging around and not posting.

 

[snowjay]

When your gauge is floating around like that it is definately time to change the sending unit and yes you'll have to drop the tank.

Funny that you also mention that when in OD your truck is lugging/luching. I had this happen with my 94 5.9 twice. The first time was do to a bad spark plug that was causing the engine to misfire - hence the source of the lugging. The second time was actually do to a faulty fuel pump. Same symptoms but I changed all the plugs and it still existed. I changed all the other ignition components and nothing changed. When I checked my fuel pressure it was on the low side of what it should be and when it would do it's lugging the pressure would drop.

I'd check your fuel pressure and if its questionable swap out the whole unit since you have to go thru the same process just to change the sending unit and the new pump will come with one. NAPA has the pump for our year for under $200. If the fuel pressure seems ok check you tranny fluid and do a change to see if that helps. Also I'd check all your wires/cap/rotor and plugs just to eliminate those as a cause.

If you want detailed instructions on dropping the tank let me know and I'll write something up for you - I've done it twice and know some tricks.

 

[jetskinjoe]

Well today the truck didnt do the fuel gauge thing, seems to be working fine.

The trans is full of fluid, I changed the filter last month. I will check the fuel pressure over the weekend and see if that is what the problem is. Thanks for the tip.

 

[jprtroy]

Yo!, How many miles are on your truck? My 94's gage started to act up last year (@130,000miles arpox.) I thought the gage was bad. The problem was the sending unit. I thought about replacing just the sending unit until I realized the fuel pump could go at any time, so I replaced the whole thing, called the "fuel module" ($248 from dealer) includes new fuel pump, sendng unit and filter. I had the help of a friend mechanic and his lift, made changing it a breeze.
Good luck....
Troy

 

[snowjay]

My 94 has close to 180k on the odometer now. The factory pump died at 60k and the dealer replaced that under warranty, the guage started acting up at 120k, I changed the sending unit at 140k and the pump died at 178k (a little over a year after I changed the sending unit). I bought my new pump at NAPA for $194. Same pump assembly the dealer will give you - made by Carter. Only difference is mine didnt have the purdy pentastar on the part # tag.