Actually a few days back, when you posted a similar problem, I found that two of my injectors didn't have the little clips that hold the harnesses onto them. I think whenever my engine would move enough, the harnesses would wiggle off a little and shut the car off sometimes. When I started it back up, the motion that starting the car makes wiggled the harnesses back on and viola!
After driving the car today and yesterday with the new main relay installed, I don't have any starting problems, or hesitation. But OCCASSIONALY my CEL will pop on and when I hit a violent bump or slam the accelerator, the car jerks back and forth like i'm hitting the rev limitor, then goes, and CEL turns off.
By now, I'm pretty certain it's the injectors. They're probably not spraying correctly.