When I first bought my 1991 jeep wrangler islander 4.0 manual fuel injected six cylinder with 99,000 mi, it was running without any problems. Shifted smooth and ran great.
Eventually it started to smoke out the tailpipe. The smoke was white and it was sputtering, not a constant white smoke. Then the smell became very rich and I could smell it sitting in the drivers seat. I started to feel and hear backfiring and the jeep hesitated when I pressed the pedal and it felt like it was misfiring while driving...and thats when I stopped driving it.
Attempts to fix the problem:
I filled the tank with gas and put fuel injector cleaner in it. I checked the coolant and it seemed ok. I checked the oil and it smelled like gas inside it so I did an oil change and when the oil came out, there was definitely gas mixed in it. It was a watery consistency and there was probably two more quarts that it should have had in it. replaced the oil filter and put new 10w 30 valvoline oil and now the white smoke is constant. Then we assumed it needed a tuneup so I bought new spark plugs, wires, cap and rotor. It did make the jeep run better and it didnt sound like it was bogging down, but white smoke was still coming out the tailpipe. With those ideas being busted, we now think that it could be 1 of 4 things.
1. The fuel injectors could be sticky and one might be stuck, allowing too much fuel into the engine.
2. The Electronic control unit could be bad and the timing could be off.
3. Cracked exhaust manifold gasket allowing gas to enter the cat converter and exhaust
4. Bad O rings
Ive done a lot of research and people with this common issue replaced the ecu and the tailpipe stopped spraying fuel and over time the rest of the crap inside of the exhaust burned off and the white smoke went away. I think I might check the injectors first and see the condition they are in. Then the O rings will be examined. Following a replacement of the ecu. I am praying its not the gasket but if these are not the problem, its the last resort.
I need this jeep running, its my only vehicle.
If anyone had this problem with the white smoke and fuel in the exhaust, please help!