boxyjeep

Haha well there we go. Should get the new sensor in a few days and be able to report back!

Yes, but I’ve heard varying reports that this is not an accurate value on the MT2500.

Thank you sir. Will let you know how it goes when I receive it. Went with the Bosch part from Amazon.

O2 sensor resistance is infinite when disconnected from the harness and measured across A/B. I'm assuming that confirms O2?

Ok, just tested the O2 sensor. B to C terminals read a solid 5v while running and A to B read around 14.3v with +-.05v while running. I believe that would point to a faulty O2 sensor. I’ll get one ordered.

The injector o-rings were replaced when I swapped out the exhaust manifold and gasket. The MT2500 is showing both STFT and LTFT at 128. It's just odd that the AFR never changes from LEAN the entire time the engine runs/starts, and only enters CLOSED loop for very short periods of time and quickly flips back to OPEN loop after running super rough. I don't have a fuel pressor gauge, but the fuel pump was recently replaced (this could be good or bad). The truck also had the fuel pump ballast resistor bypassed when I got it. I fixed that and it is now NOT bypassed.

Ok will check that.

I’ll have to check. I think it’s the pre-97 Jeep troubleshooting cartridge. I bought the bundle on eBay recently for a fraction of what it cost new 😁

It was my understanding that a vacuum or intake leak would cause a higher idle. I have replaced the intake/exhaust gasket and all bolts are properly tightened. It was my understanding that a vacuum or intake leak would cause a higher idle. I have replaced the intake/exhaust gasket and all bolts are properly tightened.

I've been troubleshooting this for awhile now and have done a lot of the suggestions on Cruiser54's site. The key issue is that the engine has a very rough/low idle and comes very close to stalling once warmed up when coming to a stop or not depressing the accelerator. I have a SnapOn MT2500, so I can see that when in OPEN LOOP mode it runs reasonably well. I've replaced the IAC, adjusted the TPS, replaced most of the vacuum lines, grounds, etc. Based on the Jeep Renix Fuel Injection manual, I believe the O2 sensor is likely bad (since it's running terribly in CLOSED LOOP mode and always in a LEAN condition), but wanted to get some advice here before I start swapping parts. I don't have an analog voltmeter to test the O2 sensor. Here's a recording of a cold start. Jump to 4:40 to see it under load and then almost stall.

Finally had a chance to mount up the brackets on a set of XJ buckets that I bought. These brackets are top-notch and fit really well. I was able to drill out the old brackets that came with the XJ seats and these mounted up like a charm. They also have an indentation for the spring mount which was great to see.

Poor thing. What is the "street" model?

A tad? :-|

I don't know why anyone keeps these. Take them off and dremel the flares to match. Looks much better IMO.

Make sure to grab those rear fender flares and the mini console. Sent from my iPhone using Tapatalk

I just installed the ZJ steering box. Works great.

You probably have a leak in the hose. I also ran into a ton of issues when bleeding an internal slave a few years back. I succeeded by letting it "gravity bleed" for awhile by opening the bleeder and just letting it slowly drain while making sure it was topped off from above for awhile, and then switching to traditional bleeding afterwards.

Just realized he has a 5 speed, thought it was automatic at first. The AW4 went through a few changes over the years, so only certain years are interchangeable. But since it's manual, it wouldn't matter.

He would have to get the transmission from a close-year XJ, and wouldn’t be able to get the front clip, etc. Sent from my iPhone using Tapatalk

As someone who recently bought an MJ in California after searching for 2 years, that’s a pretty good deal. Keep in mind that a 4wd conversion would require new TC, front axle, drive shafts AND transmission. If you’re planning the 97+ swap anyway, you’d be best to find a rear-end crash 97+ 4WD XJ on Copart and just swap everything over (including engine, harness, dash, etc). I’m not sure if you’d run into issues with CA smog doing the engine upgrade—it should be okay based on the laws, but your mileage may vary. Sent from my iPhone using Tapatalk

Read everything on Novak Conversions website. The 360 swap is probably not the best bet over an LS motor. Sent from my iPhone using Tapatalk

I believe the wiring to the O2 sensor is good (I recently replaced the plastic connector). I'll get a video of it running at 2500 RPM's. I also got a few comments when I posted this on Reddit. Mostly focused on either an exhaust leak or bad O2 sensor. Going to also try plugging some vacuum lines as a process of elimination to see if I can isolate a leak.

Another popular option is a Ford 8.8 w/ disc brakes. Same bolt pattern (but will need spring perches welded on). About 1.5" less wide, but significantly stronger than D35/C8.25.

Thanks. Will check that. When I got the truck I noticed the fuel resistor ballast was bypassed and I plugged it back in. Will try bypassing it to see if that has any changes. Will also check fuel pressure. Prior owner also recently changed the fuel pump and filter. Sent from my iPhone using Tapatalk

I've been systematically getting my '88 4.0L Comanche into better running condition and now am encountering an issue with super rough idle. I've verified the TPS voltage is good and just replaced the IAC. The video will show how the engine tries to go into closed loop mode, the short term fuel trim spikes up, then it flips back into open loop, all the while stumbling with idle. Before I replace the O2 sensor, does anyone have ideas that could cause this? The coolant and air intake temps appear good, as well as the MAP voltage. The O2 sensor reads a constant 4.98v and never fluctuates (although I've read that is expected because an analog voltmeter is the only way to read it).