Interpreting Renix Data

[XJ-Mayhem]

I'm hoping some of the RENIX wizards can chime in on the health of my 90 I just picked up, and maybe give me some direction on where to head next.



I've been working through Cruiser54's list, so far I've only done 1, halfway through 3, 8, 11, 14, 31


As for basic automotive checklist on a new used vehicle... I've only changed out the plugs for the Champion N9YC's and reused what looked like new wires from the PO. I still need to do a full fluid change.



It idles a little rough when cold, almost sounds like it has a big lopey cam, and it smells rich. The plugs helped it smell less rich and smooth out, but didn't fully take it away. It also will occasionally stumble for a second before coming back up while cold. It's been 12+ years since I've had a Jeep/my last RENIX, so maybe I'm expecting too much when I'm thinking a kitten pur idle? PO hacked off the muffler, I think I can smell the CAT is bad, and I think I can hear an exhaust leak towards the front - assuming manifold has a crack.



Anyways, here's the information dump from my REM II in the order it presents it. The initial numbers are cold after just starting, and the 2nd/3rd numbers are if they changed after warmup/a drive around the block




16-17 Hg of vacuum
12.8 Hg of MAP vacuum
1.6-1.8 V at MAP
30.0 Hg BARO
90* Water - 180 * Water - 210* Water
65* Air - 108* Air - 138* Air
13.5 Battery
13.8 V O2 Heater - 13.6 - 13.3
1.9-4.8 V Oxygen - 2.4 - 1.78
14.8-16.0 Air/Fuel - 14.9 - 14.7
Rich Exhaust - Rich - Rich
Closed Exhaust Loop - Open - Open
Off EGR - Off - Off
590-700 RPM idle - 590-650
116 IAC Turns - 109 - 64
17% Throttle
0.88 V Throttle
Closed TPS mode
5.6-6.0 Injector M/S - 5.8 - 5.5-6
0.6 Cold Enrich - 0.0 - 0.0
70-120 Short Term FT - 128 - 128
128 Long Term FT - 128 - 128
0 knock - 0 - 0
14-15* spark advance
0 retard

 

[XJ-Mayhem]

I'm leaning towards bad O2 sensor? My smell-o-meter told me it didn't seem great, and the fact that it starts out in Closed loop cold and then stays in Open loop warm seems to indicate an issue? Am I on the right track?



I also don't know what "IAC Turns" is and why it varied so much.

 

[89Mock]

Idle air control

I jut changed my oxygen sensor. Everyone said to buy the NGK one. I haven’t had smog checked so I can’t say if it runs any different. Wasn’t horrible to replace, BUT I had the whole manifold off. There are ways to test it but you need someone under there while it’s running to see if it’s switching resistance or voltage (I forget which one) and telling the jeep to switch to open/close loops.


Ohms on the one that went bad.

New NGK one.

 

[Saudade]

You would check the voltage if doing the "live test". Pins A and B are the heater circuit. Resistance should be between 5 and 7 ohms. 4.5 looks good to me.

 

[89Mock]

You would check the voltage if doing the "live test". Pins A and B are the heater circuit. Resistance should be between 5 and 7 ohms. 4.5 looks good to me.

Yeah 291 is the one that came out when I was failing smog. Just haven’t made it a priority to drive it.