Friends to see if I can help because I'm crazy with this fault, my car started to rattle when you turn on one day in the morning (last night was fine), from there, you clean the throttle body will clean TPS, IAC, send to service the injectors and they were like new, change fuel filter, air filter change, replace spark plugs and put the ACDelco, pacifiers or change the spark plug wires, replace the two coils and failure persists, but the particular is failing when it is less than 2500rpm at any speed (synchronous) after 2500rpm the car ceases to fail, it is noteworthy that accelerated if the fault is very soft, almost imperceptible, this failure is quite noticeable is when accelerated sharply.
plastic cap that covers the coils makes the change since the previous 5meses had a leakage current but this has no crack.
3 months ago would change the timing belt, pulleys, tensioner and guides (all original) and the car was excellent.

I welcome your comments