Smash6

My son got some wrenching time on the Jeep. We installed a new headlight harness with relays, new LED headlights from Amazon, and new headlight bezels. We also installed a new TPS. Driving at night is safe now, even though the gauge cluster lights don’t work yet. We did had an incident tonight where the clutch pedal came off the master cylinder arm and some fancy driving got us home (thankfully!). It’s fixed and driving again. Turns out the cotter pin came out somehow and the arm walked off the pedal assembly. I'm embarrassed. We are still fighting the stumbling issue. I started a new thread to focus on that problem. Once we solve that, the interior gets ripped out.

My son and I are working on his first car. Details in this thread lined below. To call this rig a bucket-of-bolts is a compliment. It was rescued from a field and the PO did a lot of work to get it running. She goes well except for this stumbling/backfiring issue that I need to get resolved. The block is from a 2000 with all Renix stuff. Under load, the comanche stumbles and backfires around 2300-2700 (approx) RPMs under mid-ish throttle. I can press through it and it cleans up just fine. The motor pulls hard otherwise. If I manage the throttle when accelerating, I can pull to redline without a hiccup. But under load with the throttle in the wrong position and she's going to spit, sputter, buck, and backfire. It's also running rich, by smell. Things done to date: 1. Cruiser Tip 1 - ground refresh 2. Cruiser Tip 2 - C101 connector cleaning 3. New NTK O2 sensor 4. New Standard Motor Products TPS 5. Vacuum lines all tight and sealed 6. Plugs, wires, distributor cap/rotor, and coil are all relatively new and in great working order I've noticed some mild improvements (maybe?) and I keep hoping to find the problem and I just can't. I purchased a Renix Reader and here are my readings: Good: Ignition at Idle - 14* Knock sensor - 0 at idle Inj pulse width - 5.5ms at idle Injector Duty Cycle - 4.2% at idle (I need to check this at WOT, but haven't been able to yet) Water Temp checks good MAP - 12Hg Relative Manifold vacuum - 17.7VAC O2 goes into closed loop and indicates sweeps that I think I should be happy with Bad/questionable: Short Term Fuel Trim - ~141"The ECU needs more fuel then base to run properly" Long Term Fuel Trim - 151 "The ECU needs more fuel on average then base to run properly" AFR - 14.9-16 REM swaps between "LEAN EX" and "RICH EX" I MAY have a small exhaust manifold leak. I'm not positive it's from the manifold and if it is, it's faint. Thank you for anyone that has an idea for me to try. I'd be in your debt if you can help me solve this one!

I'm excited to see that bumper mounted up. Looks sharp!

Awesome pictures and so rad to be doing that kind of miles in a Comanche!

Here’s a video of the stumbling and backfiring. I hold the throttle steady throughout but as soon as I give it more and the revs rise, it clears up and she’s running great again. IMG_5383.mov

They’re painted on and pretty crooked. But if you squint it’s mint!

The sensor is swinging and I’m going closed to open loop as I’d expect. Tomorrow I’ll post what I’m getting off the REM. Thanks for the registry tip, I’ll figure that out!

Here a few pics

About 3 years ago my brother-in-law revived a Comanche, finding it somewhere (maybe a field) and he managed to get it drive-able, but that's about it. I showed interest and he asked, "why do you want that bucket of bolts?!" We decided it would make a great project for my son's first car, so my boy and I jumped on a plane and took a long flight, picked up the keys, and drove 3 days home. She made it. Since then, we haven't had time to fix nearly as much as we'd hoped. The biggest fix was getting the trash BA10 out and swapping in an AX-15 and NP231 from a YJ. Of course there's been a lot of small repairs along the way. We've also been accomplishing Cruiser54 tips. Updated 11/2/25 Current focus areas: 1. The HVAC is stuck on full-heat and defrost. I haven't diagnosed it at all. The vacuum system on the passenger side of the jeep is a mess and there are broken and open lines everywhere. I need to simplify it, then repair it. 2. The interior needs to be ripped out and redone to include welding in new floor pans. The dash is shattered, the lights in the instrument cluster don't work, the stereo has no memory...there's a lot! I'll follow this post with pics and will try to keep this thread updated as we continue to build. Parts to gather: -Raybuck seat cover and foam -Dash pad -Floor pans - ordered -Sound deadening -Trim screws -Flooring (vinyl or carpet...) -Driver door check - ordered -Driver window crank - ordered -Courtesy lights -Seat belts -HVAC control unit - ordered -Door mirrors - ordered