freegdr

Has o2 sensor and cts ever been replaced since youve owned it ?

Slick761

Everything has been replaced. I normally run around 195-200 Tires are at 34 psi and just barely crowning.

Slick761

I'm tellin ya dude, that's gonna make the mileage even worse. True you will get corrected numbers but the shift points will be lower. F that I'm doin mine the right way and matching my gears close to the stock gear. And for 33s that will be about a 4.56

DFlintstone

Sounds to me you got something screwy there Chad. Those mileage numbers are perfect....for 703's in open loop! I got mine (partly with your help!), from a low of 10.5, to well over 20 on a recent highway trip. (actually figured 24.9, but should have added 5% for the 235's, instead of closer to 8). Still over 20, with 300K coming right up.

DFlintstone

Added to the list! ^

gajeepguy

My 89 lifted 4.5" on 32s gets 16-18 mpg regularly with 3.55 gearing and aw4. That's up/down the mountain no less. I'd say 18-22 highway but I don't see highway much

Calculated with GPS. Average speed is 52mph with approx 2500 foot elevation change

BobF

I'd start with this ^^^.
You don't have to replace the injectors off the bat, you can remove and clean yours. My intake looked like it had thick black tar in it and had probably never been cleaned. The TB took me hours to clean. The TB, IAC and TPS would probably be an easy fix, clean the TB, IAC (be gentle), and adjust TPS per the instructions on this site. Parts don't last forever, it may be time to R&R the IAC, TPS, etc, but clean/adjust them first and see what results you get. That will get you a starting point. Right now, you're shooting in the dark. Get a plan, and work it, and write down what's going on, and apply some basic logic to it.
I've done most of the above, and I'm getting average 18mpg with hills and highway. I have a few more parts to adjust and then onto getting my 50 warm up starts to make sure the computer is set right. It's a process. On this old vehicle, replacing or fixing just one part of the 'system' is probably not going to show very much improvement in anything.

I'd start with the stuff that doesn't cost much in parts, just your own labor. Work from there.

Guntar13

http://www.lunghd.com/Tech_Articles/...iagnostics.htm


go to this site and start testing. I have an intermittent problem with mileage on mine and i have fought it for months. (89 cherokee 4.0). One of the main culprits is the 02 sensor, that really effects mileage. Don't buy ones from the big box stores, or maybe you will get luckier than me. I have on on order from Mopar so im giong to see how that one does. Owning a renix your gonna have to get good with a multimeter. check the 02 thats my best advice. And take the throttle body off, buy the 3 dollar gasket, and clean the s**t outa that thing its probabaly caked!

DFlintstone

Only for Renix...bit choppy>>>
https://www.cherokeeforum.com/f2/ren...ce-rms-133153/