munyanb

I cant believe that's the only code showing up, with it running like that, lol And my plugs being black as coal also.

munyanb

I can't believe the only code is for the tranny with the engine running that way. And the plugs being black as coal lol. I'll get er fixed , I got a feeling the heads coming off, but could a loose flex plate cause the governor sensor voltage to be low and the engine to run bad causing misfires and blackened plugs?

munyanb

The very rear plug is the misfire, totally black even on the electrode. but im still going to check the flywheel, could cause the misfire and noise

xjchrisc

Do the compression test. Im sure that will give you some answers.

munyanb

well I did the compression test but had the wrong fittings. I managed to scab together some fittings from a vacuum/fuel pump gauge and the worst cylinders measured 90 while the rest measured 100, and the very last one with the plug that wasn't firing was 120, better than the rest. the fittings were leaking slightly but it still measured good compression. that's weird , I expected the last one to be nothing.

munyanb

its either this site , my computer or my internet but I keep getting cut off from internet access, timing out, losing the site and losing my posts. But anyway as I'm cleaning the plugs , I noticed that what I thought were electrodes may be insulators because there are small wires protruding out from the cleaner looking ones, and tiny holes in the ones that are dirtier. all are dirty on the outside of grounds, but there were a few that had a clean center. the miss could simply be a burnt up spark plug, but now what about the knocking? could misfires cause a knock? Maybe cause piston wrist pin damage? I have no idea what kind of gas is in it, or how old. I'm going to put some enzyme fuel treatment in the gas , get some donor plugs, or test each of them first, but from what I'm seeing I need to replace the plugs. I'm even using a light wire brush and electrical contact cleaner on the plugs. That would be funny if plugs would cure it.

munyanb

Oh I haven't bought them particular plugs before so I don't know what they are supposed to look like exactly.

munyanb

I found something disturbing, when I shut the engine off the oil pressure only goes down to 40, when running it may have 60 so does that mean I'm really low on oil pressure? i'll remember to check before I test start it again. Can the oil pressure gauge be altered?

munyanb

To clarify the gauge goes completely down when the key is turned of , but when I turn the ignition on without the engine running the gauge goes to around 40

xjchrisc

Some of these 4.0's have what is known as "piston slap" look it up. I know my 96 has piston slap. Mine sounds like its knocking, but Its been my dd for three years like this. I know that some day the piston skirt will break, and I will deal with it then. Until then I just keep putting the old girl to work.

dave1123

More than likely, your oil pressure sensor is bad. IMHO, replace it with a Mopar one only. It'll save you the heartache of replacing it again. Don't waste your time looking for those expensive 4-ground plugs. I use Champion Copper Plus RC12ECC.

Piston slap usually disappears when the engine warms up. You may have a broken skirt in one cylinder. Also, the pistons will NOT come out the bottom without removing the entire crankshaft first. They may not even come out then. IDK how much clearance there is.

munyanb

Well I just got under it and im hearing the loud knocking. I did put plugs out of the blown up 5.2 I have to see if they would work better. they are slightly shorter on the ends that go in the head, and yesterday they ran worse, but I tried it today and the engine runs smoother. I will have to look up part numbers to see if the plugs are different for them engines. The loud knock was there, and I crawled under it and it really sounds like a main or rod. it's just so loud it travels everywhere. I'm still going to check torque converter bolts, but the actual flex plate to crank bolts will not be able to be checked. The guy I got this from said he had the pan off and checked everything he could from the bottom, but I'm finding out this guy is a liar. He probably found a way to alter the oil pressure gauge since I think he was in the stereo which is right beside the oil pressure gauge. Now I'm wondering if the pan can even be taken off in vehicle ? I can't pull the engine where I am now , at least I don't see a way yet. And if I do get into mains or rods is there a cheap performance upgrade? I sure doubt it, I guess I can check the for sale section here to see if anyone is selling stroker kit cheap. In theory since this is 2WD i almost would like to make a street sleeper or something with a little more power. a supercharger would be great, but i am on a low budget and will probably just try to fix it. I do have a friend trying to get rid of some 20" wheels or 22" not sure which that are unilug and were on a big Mercedes. I'm guessing the bolt pattern/diameter will be close enough for unilugs to fit.

dave1123

In most cases, loose torque converter bolts quiet when the trans is put in gear. If the flex plate was loose, the starter would be grinding.

The 4.0 is a torque motor that produces it's max torque at 4000 rpm and runs out of power quickly after that. A stroker will produce more torque but will have the same characteristics. You just can't beat an old horse and get more out of it. After all, that motor design is over 50 years old. You could say the same about the small block Chevy, but that's a totally different horse!

Don't run the engine too long with the short plugs in it. The exposed threads will carbon up and cause problems when you put the right plugs in it.

IMHO, just replace the engine and drive it. Don't waste your money on a lame horse.

Oh... and by the way, that WJ weighs 4000 lbs with only 195 hp.

munyanb

I have been told before that the WJ weighs a lot. How much does a ZJ weigh? I am going to try to fix the bearings that are bad. I was reading a post on here that a guy made a 4.6 stroker , but that post was hard to follow and had pictures of computer screens with dyno tests that I couldn't read. I don't have the funds to build an engine anyway , I was just curious. A WJ built for street racing would be a cool ride though. If that guy had not straight up lied about checking the engine out it would not have been a mystery at all, I think people like him should go into a database so everyone would know not to do business with him. But that could be abused also. It's just the American way these days to be a liar to get ahead, look at all our politicians and business giants, that's the role models people have to look to.

dave1123

Now you're talking! I think a WJ with a 6.4 Hemi would be perfect, however the hood and front fenders have to be stretched 4" to do that! Then add nitrous and a pair of turbos and you'd have a truly fast jeep. It only takes CASH and a lot of time. You'd also have a lot of trouble making it street legal.

AND I'm telling you now, if you want honest people, stay away from Craigslist.

Actually the WJ is listed as 3980 lbs, the ZJ at 3500, and the XJ at 3300. Those are with the 4.0.