I have recently been through multiple sets of spark plugs. What happens is I will replace the plugs with brand new ones and all four cylinders in my 2.5L will fire properly and it will run better for about a day, roughly. I'll frequently pull the plugs and make sure they are burning the proper color since I have been having problems with my jeep running rich lately.
Usually, my plugs will burn black. If it isn't burning black, the plugs will burn a very dark brown color... But usually, more often than not, all plugs will come out black. Sometimes, but rarely, one or two of the plugs will come out wet. Every time I put brand new spark plugs in my 2.5L, the plugs will burn a light tan or greyish white color for a period of time (about a day or two), and then days later I'll check the color they all are burning, and they all come out extremely dark or black, once in a while one or two will be wet.
I've done a compression check on the cylinders a couple times now. I've got these levels of PSI:
Cylinder One: 105 PSI
Cylinder Two: 125 PSI
Cylinder Three: 107 PSI
Cylinder Four: 124 PSI
Knowing these numbers, I was told that the valves and rings are fine. They aren't perfect, but supposedly "no need for a valve job". I know these levels on the compression tester gauge should ideally be extremely close to each other in PSI levels, but am wondering if these readings are OK, knowing the fact that every other cylinder is higher than the other two, like my readings above show.
Also, I have black "soot" lined in the inside of my exhaust pipes. The exhaust smoke comes out normal though. It's just a thick lining inside the exhaust pipes that are covered in black.
If I had taken the down pipe off, which I have done before to diagnose some other miscellaneous things, I can start the car up and intermittently, but extremely frequently, see small flame coming out of my exhaust manifold. I was told by multiple people, including Que89yj, that this abnormal flame coming out of the manifold itself is caused by a car running so rich that the excess unspent fuel sucking into the engine is spit out of the manifold and down the exhaust itself. On its way out, it can and/or will ignite.
Also, when I very recently replaced my entire exhaust system including the exhaust manifold, down pipe, catalytic converter, muffler and tail pipe, after about 200 miles or less on brand new exhaust my catalytic clogged so much and so quickly that it started glowing redish orange and started smoking like crazy. I took the catalytic off and replaced it with a test pipe so I was able to drive to work without it happening again, knowing I never cured the root of the problem, which would be my car running so darn rich.
Currently, I am stuck getting 13 miles per gallon in a 4 cylinder TBI with 30 inch tires. I should be getting way more.
Another thing... Every time I turn the car off, seconds later I will hear some type of fluid dripping internally from inside the engine. To follow this, right when the fluid starts dripping internally I will hear a light ticking noise that eventually slows and dies down to a stop. The ticking noise and fluid dripping noise last roughly ten or 15 seconds, and stop at roughly about the same time of eachother. My engine is always lobing. Sometimes it will lobe a lot more than other times, but it always does it.
Lastly, not every time, but maybe 40 percent of the time at random, I will shut off my car and hear a loud pop, like a fire cracker go off, and it is coming from the tail pipe. It seems to have started ever since the exhaust was replaced completely, especially when I replaced the brand new clogged catalytic converter with a test pipe for some reason.
What do you think this all could be? Here's what I replaced that may help you all understand:
-New EGR Valve, now tested and new one works fine
-Fixed all vacuum leaks
-ALL NEW Sensors, every single one of them besides the CPS...
-Brand new "OLD STOCK" discontinued, never had fuel in it TBI unit, factory part from chrysler. Not an aftermarket part. Costed me a fortune, but worth it...
-New fuel pressure regulator
-Cleaned out EGR Tube, wasn't clogged
-New ISA Motor
-Tested canister purge control solenoid, works fine
-All new spark plugs, of course
-New plug wires
-fairly new rotor and distributor cap
-WOT Switch tested and works perfectly fine
-New vapor canister filter
-New air filter
-tested compression, readings are above
-tested vacuum pressure, running at about 15 PSI at IDLE (Is this normal or do I still have a leak in the vacuum somewhere?)
-New fuel filter
-All new gaskets wherever there is a gasket needed under the hood
I've done a lot more to this jeep in the last few months than what is listed above, but the rest of it does not have anything to do with any of my current problems I've listed in this thread.
If anyone that has an idea of what my problem(s) could be can please post back and help troubleshoot this, that would be very appreciated by myself.
I know it is a very long and detailed post, but I figured I'd need to give as much info as possible for this...
Thanks guys, you've always helped me figure it out before, I know we can do it again.