v8 starting problems

[pa22160]

Going nuts. 2002 Grand Cherokee with 4.7l v8. After the engine has cooled down a bit (after it sits 30 minutes or more) several cranks are required to start. Once it does, the engine stumbles for about 20 seconds and belches gray smoke. It then runs fine. If the engine is warm, it starts immediately. Have replaced fuel pump, fuel filter, oxygen monitor, throttle position sensor, plugs and coils. Fuel injectors check out. Have had it to 3 independent mechanics and 2 Jeep dealers. Nobody can figure it out. has about 120,000 miles, but the problem started at about 95,000 miles. I can't believe that this is the only Jeep that has this problem. Any ideas?

 

[dingus]

clogged exhaust?