Hey all, Once again it has been awhile. I am having an issue with my WJ(4.7L), again. I am sure it is at the end of its life. Last November I decided to not quite rely on it as my daily. So admittedly I got myself a Subaru. I have not used it much since then. Starting it up and moving it once every two weeks. But it was not registered/insured so I never left my cudisac A month ago though I needed it again, to tow something. So I made it legal again and picked up a trailer a good 50 miles away. On the way back I started having problems. I'll list everything in points, cause IMO it gets really, really weird.

-While idling for about 20 minutes when I first started using it again. This was After driving 40 ish miles and using it to go to work/school that day. It started running really rich. Though the code it gave was a lean on bank two. You could smell it.
-Pulling the battery though and reseting everything fixed that issue for a good while.
-So, for the next week I have been using it to tow things. I was the only one who had something and had to use it every other day for a few weeks. During that time I noticed it was leaking coolest again(The hoses and radiator has been replaced twice in five years). And that it won't hold a charge, the battery seems to die over night. I replaced that battery under warranty after the first time. It keeps happening.
-Now, Big issue. At the end of that next week, I had to use it. I thought I got every kinda fixed, or at least managed. And it started running rich again, smelling pretty bad. I thought, ok I'll get where I need to go, one mile away and then take a look. In the next 1/4 mile it got really bad.
-It started smoking, this was the first big symptom. You could smell it. It seemed like it was coming from the alternator, but I not 100% sure.
-The "Check Gauges" light came on, cause the Oil pressure gauge went to 80.
-It started sounding like a diesel. I know, weird description. But, the noise the engine made in those two-three minutes it took me to find a parking lot, was exactly like my fathers old power stroke.
-The engine would not stay alive the hour after.
-So, It was obvious something failed. I had a friend tow me. I started it for a split second a few hours later when I was about to have it pulled across the city, and much to my surprise it started up.
-I had it towed to my house and left it where it was for a week. I had to leave town(all of this was the night before a trip).
-When I got back it needed to be moved, it was in the way. I figured I would start it for 5 seconds. But, much to my surprise(again). It started perfectly, Idled perfectly. Acted like nothing ever happened.
-Fast forward to today, as I felt I need to move it again. Really not sure if I should trust it again. And it is having problems. Not quite as bad, but problems.
-The "Check gauge" light is on again. Its not quite at 80 though. Just barely at the 3/4 mark and holding steady.
-There is a smell.
-I can start it, and it does idle. But, it takes forever to start now. When I first started it today it was quick.

So, yeah. A lot of information. Honestly, I am not sure. I really am not. I would like some advice.

 

Next time it starts to run "rich/lean" (either of which could cause a fuel smell (too lean means not a complete combustion which leaves unburned gas in the cylinder/exhaust)) try unplugging the oxygen sensor (this is more of a problem on 4.0s than 4.7s but it could still help... maybe.)

When was the last time you changed the oil? or checked the oil? Its not uncommon for OPS(oil pressure sensors) to fail and cause false readings. but it's still good to know you have clean oil, it's possible you have a sludging issue going on.

The battery terminals on jeeps are notorious for failing and can actually cause the PCM to reset itself sporadically.

Your knocking noise could potentially be a bad water pump which would also coincide with a coolant leak. although if this was the case my guess is that it wouldn't stop making the noise once it starts. has the temp gauge ever read hot?

You need to get the faults read though so we have a better starting point though.

What faults are stored in the ECM exactly? I imagine there has to be more than one.

 

2nd.

Check your oil, and make sure you dont have any coolant, or a strange line on the dipstick just above or below the oil on the stick.

Also the sensor Dave mentioned, i had to do this with an '03 Chevy i had, all the time.
Had an impossible time starting, sometimes hard when running, and often on failed starts you could hear the gasses leaving the engine in a big "whoosh" after letting off the starter.

Disconnect the sensor, start the engine. Let it idle for a min, then kill it and plug the sensor in. And restart

 

fuel pressure? when my pump went it ran like a diesel, lean misfire, dangerous for engine parts. However does not explain the heavy fuel smell and odor. You need some basic diagnostics routine here to rule in/out a few more things. Sounds like a cylinder lost fuel. Hope that helps