multiple misfires

[johnny quad]

I have a 1999 explorer with 4.0 sohc. It throws the po304,po305,and po306 while it is running and has no power for a couple of minutes then starts running fine other than a unsteady idle after warm up and almost stalls. The codes are not stored in the computer and no check engine light on, only flashes when it has no power then turns off. I can,t figure it out. I have replaced the plugs, wires and coil and still have same problem. It runs fine other than at idle and while it's having the misfires.Any help would be appreciated.

Thanks,

John

 

[xlr82x]

multiple misfires may mean that the intake gaskets need to be changed. Pretty typical for those motors. Wierd that there is no light on, wonder if that has burnt out somehow?

 

[johnny quad]

The check engine light flashes when the misfires are happening then shuts off when it starts running fine again after a few minutes. The only way I was able to check codes was to have my scanner hooked up at the same time i experience no power and it showed po304,po305,po306 all at the same time.The check engine never stays on.