First off let me apologize if this has been covered already. Tried the search first but came up empty. My wife has a 2005 Camry SE V-6 with an automatic trans. Over the past couple of months we have had a starting issue. Does not happen all the time hence the dealer cannot pinpoint the problem. Sometimes the car will crank a few times and sound like it wants to start and then finally the idle smooths out. Only one time I was able to catch black smoke from the exhaust while it was sputtering (best word I could come up with for a description) and only one time the check engine light kicked on. The car has been in the shop numerous times for this and was only duplicated once. And of course it was when it was not on the diagnostic machine.

Various fuel system parts have been replaced, different brands of gas have been tried and the weather does not seem to effect this particular problem in one way or another. Any ideas since Toyota is at a loss? Thanks!

We will be going on our 3rd time with Toyota service on this problem.
Also, what generation is the '05 Camry's. Feel stupid asking this.