ComancheKid99

Recently my 4.0 Renix has developed a misfire. I am starting with easiest possible cause to eliminate (spark plugs). I bought some champion RC9YC copper plugs. Have not changed them ever yet since I've owned the truck. What is the acceptable gap for these 4.0s? I have read between 0.30-0.35 is fine, some say 0.35 They all came 0.30. But I do have a gapper tool. Am I just overthinking this is 0.30 ok? Thanks

1989 Jeep Comanche (Pioneer? Has dummy gauges though?).. 2WD Longbed 131,000 Miles on it as of posting... 4.0 Liter, AW4 Trans, Dana 35 and Chrysler 8.25? - Build Date; N/A? (Can't find) - Current location; Northern CT. Prior location: Delaware (before purchased). - Status; Summer daily driver / work truck / forever project. - Have done a fair amount of wrenching on it since I've owned. Has not left me stranded (yet). Couldn't ask for a better vehicle for a 35+ year old truck. Minimal rust for a northern Jeep, very clean underneath. Typical rust spot in bed driver side fender... Plan on welding keypart panel and repainting truck eventually. Only drove it handful of times in winter... and fluid filmed it prior. Believe it was originally black - and rattle canned red.

Managed to remove dash on passenger side. Fuse had a hairline crack on the red plastic part. I tested it read fine but replaced it anyways to no avail. Still have same issues no auto shifting. Should I look for a used TCU or check junkyard next ? Any advice would be appreciated.

Are there any videos or guides on how to remove the passenger dash panel? I've never done this before

Hello. First post here. Lurked the forums for a while now. Have an 89 Comanche 4.0 Auto 2wd with 129k miles. Owned it just barley over a year now. It's been a mostly reliable truck up until now. Never left me stranded except for a flat once. Mostly just drive it around town 30mins-1hr. Use it mainly for hauling scrap, wood and garbage runs to local dump. Doesn't wanna shift out of first few gears it seems? High RPMs accelerating at first. Once it gets going out of the first few gears it seems fine. Until you hit a complete stop it stalls out / feels like it's in neutral when first accelerating. Just doesn't wanna seem to go... Oddly though I noticed it works perfectly fine in reverse. I do have the Renix Engine Monitor (REM). Under trans info the REM doesn't read the gear it's currently in. Displays gear as " ??? ". Says solenoid 1 and 2 off. (Highly doubtful they could've both went bad at same time?). Shift point logic says off also (I'm unsure what that is even for). Could the TCU itself be bad, causing these weird trans issues? I'm no mechanic or Jeep expert. I got this truck as a project vehicle mostly to learn as I go. Also because fond memories of Dads '86 MJ when I was very young. Any advice or guidance on where I should start to address this issue would be greatly appreciated! Few things that I have done so far; -Removed and cleaned the throttle body. No difference. (Definitely needed it anyways though - had a lot of carbon build up). -Checked trans dipstick - it's seems fine. Normal color. Not low. -Refreshed ground by the oil dipstick per one of Cruisers tips. Didn't look like a bad ground. However I refreshed it anyways to no avail.