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I got the fuel pump in the mail today, so hopefully I will know by the weekend. Thanks!

That would be simpler than an ECU, or chasing wiring. I will order one and report back.

I have been chasing a problem for a while without success, and have some time over the next couple weeks to dig into it. After driving for 30is minutes I lose power on my 1986 2.5L. It is manual, and I can push the clutch and rev the engine without trouble, but any load lugs the engine. If I restart the engine I can get a minute of motion out of it, but the problem comes back quickly. I only take short trips with it now, and don't get on the expressway. I have checked the fuel line to see if I am getting vapor lock, but it doesn't run near enough to anything hot, and it happened during the Missour winter as well. I added a ground wire near the fuel pump a la Cruiser54 tips, but that didn't fix it. I got an REM from NickInTimeDesigns to help with diagnostics. The engine starts running lean and goes into open loop when the problem occurs. The O2 sensor seems to be giving reasonable readings. I was about out of gas once when it started, and after filling up if ran fine the rest of the way home, about 10 minutes away. Could the fuel pump be failing? I have repaired a lot of wiring under the dash as when I got it a couple years ago the e-brake had cut several wires and melted some stuff, so some sensor could be disconnected or connected to the wrong thing, or the ECU could be damaged. The reprieve I get after restarting makes me think it is ECU or sensor related. Anyone have experience with this or have suggestions?

The engine is out now, and the front body panels are off. I can't see any damage to the drivers side. The passenger side frame rail is accordianed for the first few inches, and has some buckles further back. The last buckle I can see is right behind the shock. I am hopeful that the cab is not bent, and I can't see any signs of damage to it other than that the passenger door has a gap at the top.

Hey folks, I am working on bringing my Comanche back to life after an accident. The wreck was back in October 2017, and the old gal has been sitting in my driveway waiting for me to figure out what to do. Back in 1988, my brothers father in law bought the truck new. My brothers wife was born that year, and she rode home from the hospital in it. She also learned to drive in it, along with some of her sisters. The truck was passed around the family, and I ended up with it a few years ago. It is a 2-wheel drive manual transmission, with the inline 6 engine. I asked for advice in this post, and I have proceded to remove the engine and get it ready for the auto body shop.

Thanks for all the advice and information. Here are my options, as I see them. I am leaning toward #3 of #4 after removing the engine, transmission, and anything else that may be in the way. Getting to do a bunch of work on it is half the reason I like the vehicle. 1) Buy another MJ, and use this one for parts to get the other working. Pros: No worries about a weak frame. Similar in price to repairs. Possibly fewer man-hours for me. Cons: Loss of a long time family vehicle, possibly family strife. Similar price to repairs. One less MJ in the world. 2) Bend and tweak on it myself. Pros: Cheap way to get it drivable. Cons: Weak frame. Frame will never be truly straight. Will never drive the same again. Unsafe for normal roads, only for use on trails. Its days would be numbered. 3) Have the body shop cut the frame and weld on a new frame rail. Pros: Fully working and drivable vehicle once everything else is done. Strengthens the world MJ herd. May be able to pass it to the next generation. Cons: Expensive (cost can be mitigated by stripping it down myself). If the cab is tweaked, this will not address that problem. Frame stiffener kit will probably need to be installed (not a bad idea anyway). Lots of man-hours of work for me. 4) Have the body shop straighten the frame. Pros: Fully working and drivable vehicle once everything else is done. Any other problems with the frame would be discovered and could be addressed. Strengthen the herd, grandkids may love this MJ one day. Cons: Expensive (cost can be mitigated by stripping it down myself). Frame stiffener kit will be required. Lots of man-hours of work for me. I plan to open up a rebuild thread for that process. Winter has been rough, so it may be a while before working in the driveway is feasible.

Thanks guys. If it weren't for the family ties, I wouldn't think about repairing it, and I have been tempting myself by looking at MJ's for sale. What is the down side of cutting and welding on a replacement frame section? Is the end product a weak frame? Can it be helped with a frame stiffener kit?

I am the somber owner of the families 1988 Comanche. It is 2-wheel drive, and has about 120,000 miles on it. The truck was purchased new in '88 by my brother's wife's father, and it has been passed around between different family members. I smashed up the front in an accident in September of 2017, and have been trying to decide what to do ever since. I towed it to a body shop recently, and they can weld on new front frame rails for $2400. This is expensive for me, but I probably can't get away without repairing it in some fashion. Is this the best way to go about repairs? The main damage is on the passenger side, and the third picture shows the buckle in the unibody that is the furthest back, right by the shock. I can tackle the engine repairs, but don't know how to weld. I read somewhere on here that unibody damage can be fixed with a tree, a come-along, a big hammer, and heat.

You could try enlarging the holes that the bolts go through so that is sits a little further out from the flywheel. I tried to get the CPS closer to my flywheel that way and broke one, but it should work in reverse if it is already too close. Also, the flywheel is partially open to the air (at least on my '88 Comanche), so I don't think the missing grommet would cause trouble as the chamber is not sealed.

I wonder if I cocked it back toward the teeth somehow. The molded plastic part is "L" shaped, but if something was propping that out I would expect to have had more trouble tightening it. I don't plan on taking anything else apart to get a better look, but maybe I need to get a mirror.

Update: Made it to another weekend, and got the second CPS installed. It runs like a champ now. Thank you all for your help. I never did find the piece that broke off, but needless to say I didn't drill out the second CPS. Now I just need to weld up the holes in the flooring, replace the swiss cheese exhaust, find out what is squealing, get the stereo to stop buzzing on low tones, get working door locks, etc. I can see why this can become an obsession. Obsessive Comanche Disorder?

I picked up a CPS from the local Napa, and drilled out the top hole to 3/8", and installed it. It fired once, and that was all. Pulled out the CPS, and the end was broken off. I ordered another as that was their last, so will try again tomorrow. My question now is, do I need to get that 1/4" piece of plastic and metal out? Is the metal piece on the end magnetic, and will it cause trouble sticking to the fly wheel?

I checked the CPS according to Cruiser54's tips, and am only getting 0.035 VAC, so I think that might be it. I have yet to do the ground reworking, as that is what I had planned for this weekend until this came up. I also checked the resistance on the 02 sensor and was getting 800 ohms, so that may be bad as well.

Just got my Comanche (1988, 4.0L inline 6 cylinder, 2wd) a couple months ago, and have been working through the various quirks. It drives has been driving well, but two days ago I had to get towed home. After driving for about 20 minutes, it died at a stop light. Turning the key would crank the engine, but no fire. I tapped on the fuel filter, poked about in the engine, and tried to start it for a while, but didn't want to run the battery down. When my tow got there and pulled me into a parking lot, it started, but it died again after a few blocks and had to be towed the rest of the way home. Looking around the forum here, I see it could be an O2 sensor, the ERG valve, or the IAC. I pulled the IAC and cleaned that with some Carb cleaner. I killed it by pulling on the ERG, but it started right back up again. I let it idle until it died (about 20 minutes?) and it won't start now. I will be checking the reading on the O2 sensor once I can get it running for a bit again. I have only a little experience working on cars (thanks for the pinned Acronym list!), so any advice you can give me would be great. Thanks in advance.