That's how I determined the fuel injector leak :-) was the spray test. N

 

http://www.naxja.org/forum/showthrea...ht=sensor+test

https://www.cherokeeforum.com/f51/he...ix-links-1397/

There's some renix stuff there. forget if you saw that already.

 

I know it's not the O2. I've unplugged the O2 and get the same results. You can imagine how frustrating this problem has been lol. The fuel pressure reg is the last shot before I have to think about selling her. Since we're moving in a month. Maybe I can purchase 6 gnomes, and have them all pour the right amount of fuel at the correct rate into the cylinders!

 

Did you ever pull the ECU and refresh the connections?

 

Not yet, that is on today's list. It's not a random problem anymore. It's all the time.

 

It's the damn CTS again. This new one still tests good *much like the old one* I think I'm going to replace the wiring directly from the computer too the sensor. In the mean time, she runs great with it unplugged.

 

Just thought I would share this, basically I had a very similar problem. Most of the time my 87 4.0 would start, idle and rev fine, sometimes rpm's up and down other times it would cutout going down the highway a lot or a little, depending on the day. It could run fine for several days then hardly run at all. New ICm, plugs and wires, distributor cap and rotor, and new fuel pump. The problem would not go away. Replaced the coil and what do you know, runs like a top. Go figure!

 

Makes you wanna try this, doesn't it?

Renix Jeep ICU/Coil contact refreshing
　
　
The contacts between the coil and the ICU on your Renix Jeep can become corroded and loose causing a complete or intermittent no-start condition. I recommend the following procedure as a maintenance precaution to insure this is eliminated as a possible cause now and in the future.
The coil is attached to the ICU by two T20 Torx bolts. Remove these two bolts and lift the coil up off the ICU. You will see 2 pins and 2 sets of contacts. Clean both the pins and springy contact pieces with a good electronics cleaner.
Squeeze the springy contacts closer together with some needlenose pliers. Apply some dielectric grease to the contacts and bolt the coil back on to the ICU.
While you’re right there unplug the connectors from the ICU and inspect the pins in the harness connector. Make sure the pins are not retracted into the connector. Spray out the connector and the receptacle of the ICU with the same good electronics cleaner you used earlier. Apply dielectric grease to the connectors and plug them back in.
I feel this procedure should be performed at least once in the lifetime of a Renix Jeep.
　
Revised 11-29-2011

 

Just an FYI. I had already done this when I replaced the ICM (Some use the term ICU) either way, same hardware. The ICM failed the test at my local auto parts store, and this is why I bought the new one. It was just a fluke I took the ICM back and asked to test the new one with the old coil. The brand new ICM failed also with the old coil, luckily they had a new coil in stock and I swapped it out with the old one while I was there and the new ICM passed.
Before spending any money, it is a good idea to follow the procedure in the previous post. Again, it was a fluke that I found the problem. Coil's normally just die, but OH NO not this one.

 

Glad you got it figured out.

 

Black smoke...misses and wont run..acts like it is flooded...I keep starting it and it keeps quiting and when it finally warms up, it will run ok, but then when I turn it off again..same thing...missing, black smoke....HELP!!

 

This is the wrong place for Liberty's. Most of us only know XJ's. Try asking here:

http://www.lostjeeps.com/forum/phpBB3/

 

Nancy, "we" have a tube/vacuum line from the throttle body, (sort of where a carburetor would have been), to "Our" MAP sensor up on the firewall. If it is off or broken, cracked, clogged, the computer will think the throttle is floored and dump a bunch of fuel. (that makes black smoke)