New Ecm is on the way. actually.

 

I know you don't wanna hear this again. but have you tested your sensors? I would hate for you to have gone to the trouble of getting a new ECM over a bad sensor. The new fuel injectors were a smart choice though

 

x2 on that ^^^

 

I suggested a bad MAP sensor in the BS thread, or a vacuum leak to it. When i had this on mine the mix was very rich and i had a bad MPG.

 

AS I SAID!!!!! i wouldnt fool with the ecm exept for a performance chip, or tuner. what is the problem with that???

 

Because multiple people have done that with the Cherokee ECMs and had bad results. Not to mention its not worth the hassle unless you're doing some ridiculous crap to you 4.0. In which case you're better off just doing custom piggy-back fuel management. With these Jeeps, messing with the ECM is just asking for trouble, if you honestly want more power you can do small stuff like headers, intake and bigger injectors. If you want a ton more power, just stroke it and stay with the stock ECM. Don't send him off on rabbit trails, thats not going to help anything. If the ECM is bad, he's gonna find out in the next few days. Ifnot he needs to go sensor huntin'

 

I disagee. But this was an off topic post although not really an attempt to hijack the thread. So maybe we can start another thread and see what your supporting evidence is..

 

I'm not gonna get in a pissing contest with you. I'm here to try and help out 4.0 get his milage back

 

Pray tell..... what is your estimation of good mileage for 4.0 ??

 

Good mileage? 20+ miles a gallon. Average with his set-up? 18 or so miles to the gallon. If you want to be a douche please either PM me or take it somewhere else. Keep it off of his thread.

 

Thanks for your information

As for your opinions, everybodys gotta have at least one......

 

I really don't appreciate this comment really. I do not have the equpiment to scan the electronic devises so I a paid a reputable mechanic in my area to look over my jeep. He said that the sensors are fine, it is either a messed up ecu or a major blockage because of carbon. Since then I have ran 3 cans of seafoam and it is still running the same. For leakage I sprayed B12 around the intake and exhaust and TB to see if it surged or anything like it was sucking air in from somewhere and it didnt change anything. Checked PCV and no cracks or leakage there. So I would really appricate it if you would not call this a BS thread, when I am having problems with my jeep and I ask for help. I listned to you advice and tried it, and you still complain. There a many people watching this thread, and I hope that I am spending the money in hopes that others will not have to just guess like I am having to. So once again please keep comments like this to yourself.

 

4.0.....Is there any chance you have omitted checking the air filter and any air leaks on either side of the TB?

 

did this mecanic check codes or did he actually check sensor readings, sometimes a bad map sensor or a tps sensor will cause a slight surge at idle , rich misfires , and poor fuel mileage. No codes may be present if the sensors are reading inside the rang their programed to read in, but still be reading wrong, causing excessive rich conditions because the pcm thinks there is more load on the engine than their actually is. The difference between a good mechanic and a mechanic is knowing what you should be reading not just what you are reading

 

i have the same problem as you, i do have the means to check all my sensor signals and all mine are normal, im gonna test for a leaking inj. tomoroow let me know how that ecu turns out. My purge solenoid was ticking (actuating) at idle, i unplugged and it seemed like i was getting better mileage but i dunno a cyl 3 misfire was read while it was unplugged and i was driving, fml