It is strange that it takes 5minutes to show up daes it brake up or chock out when it starts to happen when you go to the floor with gas petal.also on the distributor is there two connection that are plugged in or one with two wires if there are two one with two wires and one with four wires at the front of the distributor disconnect the one with four wires and see if the problem goes away if so you could have a problem with the est in the computer or the Inigion module also by disconnecting you are by passing the governor because it looks for a tack signal to the controller under the dash to control the vacuum to the governor if you still have a problem get back to me and we will look into it more good luck.