well i own a 2001 Ram its been lowered has the 5.9 magnum in it singal cab right at 82,000 on the motor have no clue as to way i can go a few miles down the road and back and actually see the gas neeedle lean towards E at an abnormal rate, also it has a skippy idle not to bad but as i go to leave in it it kinda does not accel. and skips a little until i give it more gas then she picks up any ideas???

also i know 5.9 dont get good gas milage but u should not be able to see the gas needle move drastically like that driving normal

 

Check to see if there is a hole in the tank...

But seriously it could be a lot of things. Definitely start with a tune up and check the plenum.

 

well the gas miliage dont change until i drive the truck and i dont smell gas no were around it so that rules that out, but i do a regular oil change plug and wires airfilter on a regular basis matter of fact not long ago

 

cap, rotor - and check the plenum

 

read the first thread on the home page

 

whats the actual mileage, maybe the sender is going bad

 

ok checked the plenum its still fine from last tune up and the actual miles is 85,386 thats the original engine my pa had this truck gave it to me not long ago been driven maybe once a week when he had it now i drive it for fun and now its just has some crazy MPG

 

I don't think you understand exactly what is being referred to when we say "plenum".
A tune up will have no bearing on whether or not the plenum is fine.
There are currently about 1000 threads on the board about plenum gasket failure. I think one has recently been stickied.
It's by far the most likely cause of poor mileage, followed by old O2 sensors and a tune up.

 

Check your pre-cat o2 sensor. How long has it been since the last tune-up (cap/rotor/plugs/wires)?

How many miles are you getting per tank? It could just be the gauge reading wrong.

EDIT: aim ninja'ed me.... +1 on what he said about the plenum, I didnt read your previous post thoroughly or I would have suggested the same. Read the top sticky on this forum for more info on how to check/repair it.

 

I'll add that a full tune up requires you to also change the cap and rotor on the distributor. Those two components go bad as quickly as wires and plugs.