Valve or Crank issue Jeep Grand Cherokee Laredo 2005
No former issues with the Jeep (6 cylinder). Needed to replace the front crank seal but didn't. Also should have replaced torque converter. Pulled up, pumped gas- won't start- chugging for air or gas- tried jumping it- person jumping it said don't keep trying to start it I think it is the valve or crank. Checked many little things including the plugs. One was wet with gas, all were dirty and one had the top arc pushed onto the plug. Darker smoke out of the tailpipe.
My brother added Risoline which made it run better at 20mph without stopping/gas and I could have gone faster. Slowing wasn't an issue, but when I wanted to stop, it wanted to stall. The vibration and all the symptoms are still present. My brother doesn't have anymore answers.
I was told the sound was louder and that would mean a crank, but my brother thinks it is a valve. I am wondering how to know what is really wrong before I shop for a price to fix it. Can anyone help?