If all that doesn't work and it still has that stumble, then I'm dropping my bid to $18. I can't afford to keep shoving money into another Jeep.

 

LOL thanks but dont forget I have tv's so those are worth something right? LOl

 

$18 without the tvs, and $127 with them. That's my final offer.

 

ok well i will let you know if a week what i am going to do with it. I should do a compression test while I am at it.

 

Alright wow.

I am having the exact same syptoms as you right now. I singed up to this forum specifically to reply to your thread. My 98 4.0 is getting about 10 mpg with loss of power, slight smell of fuel under the hood, black soot on relatively new spark plugs and no codes thrown.

So the thing is running rich right? Why?

So far iv'e changed almost everything you have. All fluids, O2 sensors, air filter, i even threw on a dynomax cat back. no change in power or fuel economy. This is killin me. The next step i was going to take was get an alignment.


I know there are a bagillion threads out there relating to MPG, trust me Ive read them all, but it seems we're in the same boat here. It seems crazy to be getting 10 MPG on 31s with a light foot while other guys out there running 35s cruise around at a solid 18 MPG.

I'm hoping we can help each other out here and keep up to date with any progress.

 

will these injectors bolt right up to a 4.0? http://cgi.ebay.com/ebaymotors/19-LP...#ht_500wt_1182

 

Sweet Welcome to CF!!!!!!!!!! Yea did you change injectors? I was thinking today maybe my Map sensor is messing up as well.

 

Hey 4.0cherokee which injectors will bolt up to a 4.0 Cherokee?

 

Thats what they say, but mine look a little different though.

 

Havn;t changed the injectors yet. What would be wrong with the injectors causing the prob? Yeah i was thinking map sensor too but wouldn't it throw a code if it was messed up?

 

This helped me a lot.
https://www.cherokeeforum.com/f2/mor...estions-13848/

 

I have ran a lot of seafoam through mine and I hope the injectors are just messed up to the point they are just kind of just squirting the gas in instead of a fine mist so it can burn a lot better. The cat is getting replaced because it might be plugged up from all the excass fuel that is just getting thrown at it. So if this doesnt work i know where this a 99 that was a cash for the heartless and I will see if they will let me test it before i buy it and the computer while I am there.

 

i have installed the orange 19lb bosch injectors, two bottles of seafoam, cleaned throttle body, new k&n intake, new champion plugs, muff. new tires, front end alignment. amsoil full synthetic in engine and axles and it still sucks the fuel. they only thing i havent changed was the other two cat. converters and the four o2 sensors, and yes there is 4 of them, two updraft, and two downdraft. i dont know what else to do either. i would have to calculate my milage again, and i was told that with the 31x10.50's that i would have to multiply that by 1.25 to calculate for the tire size difference in order to get the right total.

 

well i am glad that I didnt have to go and get 4 o2 and 3 cats. I dont know what else to try on your setup except map sensor. Does it stumble when it is idling?

 

it does have a slight miss to it yes, similar to some of the newer gm's.