onlyinajeep726

*UPDATE* So, I re-dropped the distributor. Seems I was off, as suggested. I have it installed and the rotor is aligned just as my other XJ is. The trailing edge of the rotor contact is just past the first post. It starts and it'll idle ...mostly. Problem starts at ~1400-1500 rpm... It begins to spit and sputter, backfire and pop like there's no tomorrow. Now that it "runs", it finally threw the CEL on and I was able to pull some DTC's. I did the old key/ignition trick and used a scanner. Key trick showed codes: 12 - Battery/PCM disconnected within last 50 starts 27 - Fuel injector circuit open or not working (this code threw twice) 54 - Distributor sync sensor fault OBD II scanner showed codes: P0340 - Camshaft Postion Sensor Circuit A error P0205 - Fuel injector #5 circuit open or shorted P0206 - Fuel injector #6 circuit open or shorted I swapped the distributor pickup coil with another one and it made no difference in how it ran. It has the Neon 703 four hole injectors in it and was running fine before, so not sure if those codes are relevant. I've been told that if the P0340 code is thrown, it could also indicate a problem with the crankshaft sensor. Assuming that was even the case, wouldn't the Jeep not even run or start?

Thanks for the helpful replies. I actually have done exactly what Stroker suggested with slightly advancing/retarding the timing by turning the dizzy. However, that proved to be useless. That being said, I've also pulled said dizzy and redropped it back in a few times in my attempts to remedy this. I've set quite a few dizzy's in the 4.0 previous and been successful. Not saying that I couldn't be off this time, it's always possible. What's crazy, and perhaps I should've mentioned it in the original post, but that "binding" has been a problem since the Jeep was purchased from the original owner, but as it would seem, the problem was rectified by the PCM somehow since it was starting and running before the battery was disconnected. Also, perhaps worth mentioning, if you ever got heavy on the accelerator or put the engine under heavy stress (like we did pulling a compact car 5+ hours a couple years ago), the engine ran like crap. Sounded nearly identical to how it would sound if the vacuum line to the MAP sensor was disconnected. Funny thing is about that, that issue would go away after the engine cooled overnight and be fine by the next morning. Not sure if that's related. What I will do, is go over might work with the distributor and verify it is set correctly. Afterward, I will report back. Thanks again for all of your suggestions!

First off, I want to say sorry if this is in the wrong section. Admins, please feel free to move if necessary. Also, I realize this is an MJ forum, but y'all are considerably more helpful than the other forums I'm on. Ok, so here's the issue... I've been working on my buddy's '96 XJ - 4.0L, AW4, ~280,000 miles, pretty much stock. It has been unhooked to a battery in quite some time due to the slow progress I've been making in performing repairs between my main job. It won't stay running after it attempts to start. So far, I've done various fixes to try and remedy this, such as: - New distributor cap, rotor (brass terminals), spark plugs and wires - New timing chain and sprockets (installed just like my Haynes and Chilton manuals specify) - Checked and indexed the distributor just like cruiser54 instructs and verified wires are in 1-5-3-6-2-4 order - Used a known good, charged battery I know that there has been a similar issues with the OBD II models where to floor it to get it to start it after the battery has been disconnected since the computer has to "relearn" idle settings, but this is not the issue here as I've experienced that on this same Jeep a couple years ago. Also, something to note, more often that not, when you attempt to start it, it sounds like the starter and flywheel are binding (not a grinding sound, see the video below - it can clearly be heard after the 3rd attempt to start the engine). It's done that since the Jeep was purchased but seems like the computer compensated for it after a while, which suggested a timing issue to me, thus the whole reason I checked and replaced the timing chain and distributor. I'm stumped, so... ?!

You'll have to swap over to XJ/MJ accessories and belt configuration to get everything to clear. Also, as you noted, swapping the driver's side frame rail engine mount is necessary because the 2.5L's weight is distributed different since it's shorter.

"Chamanche"? :doh:

^^ This.

Here's some helpful information to start you off: http://comancheclub.com/topic/39539-links-for-25l-to-40l-swap/ Also, feel free to check out my build thread... I've done this swap and it's not overly complicated.

That's a nice looking truck.

^^ THIS.

Read through this... not mine, but someone local to me did it. http://comancheclub.com/topic/17566-360-fuel-injection-build/

You're surprised? The XJ's and MJ's behind the 4.0 have Toyota transmissions, essentially. The AW4 is basically the same trans. found in 4 Runners and Supras of that era.

You can use the HO style ('91+) exhaust manifold or aftermarket headers, but you'll have to obtain the HO down pipe to make it work, or bring it to an muffler shop to have a custom one made. I just went to the junk yard and pulled said down pipe from a ZJ (as those don't have a crushed end to clear the front drive shaft like the XJ and MJ ones). It would be a good idea to grab the transmission rubber mount from the cross member of an HO era XJ or MJ too, so that the new down pipe will slide into the vibration dampner that's built into that mount.

still the crappy 2.8 for my MJ, and does the e-brake have to come from another 86 MJ? Redwolf No, any year will work. Actually, it'd be preferred to not get another one from an '86 because those had a defect that was under recall back then for that exact issue, not staying in place/holding. Bad ratcheting, worn teeth. And NC still has state inspections, but I don't think they're as communist as Virginia. Also depends on where you go hehe. My foot brake was crap when I bought my MJ and never once have they checked it.

There is no direct replacement for the foot e-brake nor can it be found from any parts store/Rock Auto. The ones in the '86 MJ's are especially problematic. Ask me how I know... As far as the emissions issue, what engine does your MJ have? Is it still the 2.8 in your signature or are we talking about at different MJ?

That's sad to hear...

Awesome, glad to hear it was a simple fix!

On a more serious note, DAMN this is a NICE MJ!

Crankshaft seal... There's where mine is coming from on my XJ, best I can tell.

When you messed with the CPS plug, did you accidentally break the vacuum hose leading to the MAP sensor?

Haha, thanks man!

Bypass the fuel pump ballast and if that doesn't help, your fuel pump might be going out.

CPS? Fuel pump?

Well something ate that one lol.

August 1987 was the official buyout of Jeep from AMC to Chrysler, IIRC. '88 models built prior to then are all AMC branded. Anything after that may or may not have some Chrysler stuff on it here and there, depending on the parts that got pulled off the shelf lol.

You're better off getting a C8.25 or F8.8 from a junkyard. Don't waste your time with a D35 in a built rig... On a stock rig, running with OEM sized tires, the D35 will be just fine but I would never pay $500 for a D35 with or without mods. Who even wastes their time building a 35 anyway?