[Dbelleperc]

When I start to go the car boggs down and there is absolutly no power but enought when I am going uphill I can creep up, but a few seconds later the power just kicks and I am able to shift into second. On the freeway it does the samething where I will be going 80 and I just feel the car lose power but the RPMs don't fall derasticly but it feels like I am towing a trailor up the hill, and then when I get to the top of the hill the power goes back to almost normal were I can drive freeway speeds. When the power resumes I know it is not at full power, and when I release the gas pedal the engine backfires very very slight. The engine revs up to 4500rpm in neutral but I can tell it is not as responsive as before and lags. Can anyone help. Is it timing, valves, ignition? Thanks in advance.