Hello all,
Currently getting 11-12 mpg average per tank for the past few months or so. I've tried a number of things to try to fix the issue.
- I Recently did plugs, NGK coppers. New PCV. Swapped two coil packs.
- New IAC valve
- cleaned throttle body
- pulled vaccuum lines off my parts '04 and swapped them over so they're not new, my old lines were cracked at the "T" before it reaches my air intake tube so I just wanted to fix the leak. No vaccuum leaks detected.
- Intake filter recently washed/oiled
- New water pump and thermostat, all new Zerex and distilled water (old factory WP pilot bearing finally gone at 255k mi, started leaking)
- Tire pressure is good
- I seafoam the gas tank twice a month, so I don't think faulty injectors
- Checked all brakes, even adjusted parking brake, none are sticking
I'm leaning towards fuel pump/filter, or transmission. Maybe even both. I'm almost to 260,000 mi and fuel pump and trans are original. I've been hearing a distinct "burping" sound coming from rear driver wheel well after the KJ has been driven and turned off. Vibrations and jarring, such as closing one of my doors, will sometimes cause it as well. There are no running issues though. No check engine light. Idling at 600 rpm after warm up. Plenty of power for an out of ratio setup and an older engine. Oil and filter get changed religiously at 2,500 mi, full synthetic, leaks a quart between changes and doesn't burn much.
On a side note, there is a residue on the inside of my rear passenger brake rotor dust shield, maybe axle seals going bad? Doesn't seem like that would drop MPG though.....
Waiting on ATF to do trans filter/oil, and while I'm at it, going to do transfer case and 8.25 as well. Been awhile lol
Some background vehicle specifics, I'm running 265/75/16 with 3:73s, was getting much better mileage than this the past few years, 18 mpg highway.
Currently getting 11-12 mpg average per tank for the past few months or so. I've tried a number of things to try to fix the issue.
- I Recently did plugs, NGK coppers. New PCV. Swapped two coil packs.
- New IAC valve
- cleaned throttle body
- pulled vaccuum lines off my parts '04 and swapped them over so they're not new, my old lines were cracked at the "T" before it reaches my air intake tube so I just wanted to fix the leak. No vaccuum leaks detected.
- Intake filter recently washed/oiled
- New water pump and thermostat, all new Zerex and distilled water (old factory WP pilot bearing finally gone at 255k mi, started leaking)
- Tire pressure is good
- I seafoam the gas tank twice a month, so I don't think faulty injectors
- Checked all brakes, even adjusted parking brake, none are sticking
I'm leaning towards fuel pump/filter, or transmission. Maybe even both. I'm almost to 260,000 mi and fuel pump and trans are original. I've been hearing a distinct "burping" sound coming from rear driver wheel well after the KJ has been driven and turned off. Vibrations and jarring, such as closing one of my doors, will sometimes cause it as well. There are no running issues though. No check engine light. Idling at 600 rpm after warm up. Plenty of power for an out of ratio setup and an older engine. Oil and filter get changed religiously at 2,500 mi, full synthetic, leaks a quart between changes and doesn't burn much.
On a side note, there is a residue on the inside of my rear passenger brake rotor dust shield, maybe axle seals going bad? Doesn't seem like that would drop MPG though.....
Waiting on ATF to do trans filter/oil, and while I'm at it, going to do transfer case and 8.25 as well. Been awhile lol
Some background vehicle specifics, I'm running 265/75/16 with 3:73s, was getting much better mileage than this the past few years, 18 mpg highway.