I have a 05 grand cherokee 3.7. it would stall and start once in awhile. Then one day it just would not start. I replaced the coil packs, spark plugs, crankshaft position sensor, and camshaft position sensor. I did clean the mass air flow sensor. Replaced the pcv valve. I also looked for leaks in the vacuum lines with starting fluid.

What else would cause the popping sound after idling for a few minutes and the rough idle?
I am going to clean the IAC valve tomorrow.