Bad Mileage

I recently had the piece of fuel hose on the fuel pump break and therefore not give the engine any gas, so i replaced the fuel pump considering its a 92 and would probably go out in a week or say anyway with my luck. Also changed the fuel filter and MAP Sensor. CPS Was changed recently, within 2000 miles. A new exhaust was put on during inspection. I think the cat is still the same though. New o2 sensor as well. I went from getting roughly 250mpg to about 170. What cause the huge drop?



6 Cylinder AW4/242. Tires are 30"

did you do the basic tune up stuff as well ?? cap, plug. rotors, wires ???

hell, i wish I gould get 170mpg. Whats your secret?...j/k

Haven't done tune up yet. I'll try plugs, cap, rotor and wires. Should i also get some fuel injector cleaner and put that in my tank everytime i fill up?

MudslinginXJ said:

Haven't done tune up yet. I'll try plugs, cap, rotor and wires. Should i also get some fuel injector cleaner and put that in my tank everytime i fill up?

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I would do the fuel injection cleaner about every time you do an oil change

MudslinginXJ said:

Haven't done tune up yet. I'll try plugs, cap, rotor and wires. Should i also get some fuel injector cleaner and put that in my tank everytime i fill up?

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Try BG 44K. You'll only need it maybe...once a year. Best stuff around. Runs aprox. $25.00

MudslinginXJ said:

I recently had the piece of fuel hose on the fuel pump break and therefore not give the engine any gas, so i replaced the fuel pump considering its a 92 and would probably go out in a week or say anyway with my luck. Also changed the fuel filter and MAP Sensor. CPS Was changed recently, within 2000 miles. A new exhaust was put on during inspection. I think the cat is still the same though. New o2 sensor as well. I went from getting roughly 250mpg to about 170. What cause the huge drop?

6 Cylinder AW4/242. Tires are 30"

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Thats not good, did it do it all of a sudden or gradually ? I usually fill the tank on my 98/4.0/5sp/LT235's w/3:07's at 300mi, it normally takes 13-15 gallons, when it starts taking 18 I dump a large bottle of Chevron Techron fuel SYSTEM cleaner in and my milage comes back. Also once a year I borrow a neighbors 3M FI cleaning kit, go buy a can of pressurized cleaner/fuel and run that thru by pulling the fuse on the fuel pump and plugging the kit into the fuel rail schrader valve, takes about 20 min.
Not sure on a 92 but did you disconnect the battery for say 20-30 min and let it sit after replacing those sensors. On some it will force the management system to relearn the parameters. I know my 98 ran like crap after I swapped my idiot light panel for a gauge panel and disconnected the battery for about 3/4 of an hour. Then over about an hour or two of driving it started to get better and then back up to snuff. Also check all the air pressures, one or two low tires can cause a real drop in milage by increaseing drag.

Yes the mileage did drop all of a sudden. The battery was disconnected for a couple days while replacing the fuel pump after all the sensors were replaced. I just bought some plugs, wires, and fuel injector cleaner, gonna throw all that stuff on tonight. The Jeep also takes anywhere from 13-15 gallons. How long does it take to relearn the parameters, because i've ran this last weekend, and all this week. Tires look ok. I'll double check the air pressure thought to make sure.