2003 Toyota Corolla Engine needs to be accelerated until ca

My 2003 corolla has to be warmed for 10minutes before I can use it. If I take my foot off the accelerator it will turn of and give me a rough time to start up again. Once the car reaches normal temperature it wont turn off, but the idle speed remainns a bit low. I have replaced the spark plugs, coils, timing chain, coolant sensor and oxigen sensor. I have read the code it gives and it always says "missfire cylinder 1, 2, 3, 4" I have asked over a dozen mecanics and no one knows what is wrong with the car