dlhazelwood

i had a dead battery last summer. took the battery too get tested. found out it had a dead cell. put new battery in a week later. every since the gas mileage has gone downhill.. i could go 250 miles on 3/8 tank, now its 3/4 for same mileage.

i have drove it about 3000 miles since..

any suggestions would be great!

thank you

wheeler

i would replace the distributor cap, wires and spark plugs! thats the only thing i can think of that would give you such crappy mileage. or undo the battery, let it sit for -10 minutes, reconnect, turn key to accesroy, turn back to off, turn on and drive it normal for a few weeks and see. that process should reset the computer! 1996: you'll have the obdII comp system. maybe a burnt out o2 senser as well. try reseting the comp then the plugs wires and cap. the o2 is the biggest pain in the butt

dlhazelwood

thank you, will try it in the morning.

wheeler

no problem man. plus the cap wire and plugs should be done regularly a a tune up

jonnyb78

a bad o2 would throw a code though. u got an engine light on? wow u only drove it 300 miles since the summer?

GreenClassic

How could you go 250 miles on 3/8 of a tank of gas? That's 33 mpg. I average about 18 mpg.

Going 250 miles on 3/4 of a tank of gas makes more sense, that's 16.6 mpg.

There is no way I could go 500 miles without having to get gas.

dlhazelwood

the ecm had been reprogrammed short after the warranty ran out

my concern is that having the battery unhook for a week, could the ecm have reprogrammed back factory default

dlhazelwood

no engine light

it was 3000 miles since i put in the battery, it is not a daily driver

GreenClassic

I suggest getting an odometer that works correctly. Although, seems like it's working fine now. Going 250 miles on 3/4 of a tank of gas is normal. You are not going to get anything significantly better than this.

Going 250 miles on 3/8 of a tank is NOT POSSIBLE with the Cherokee. You will never come close to getting 33 mpg.