Engine misfire when warm

Doug,

When this happens, have you checked to see if the cylinder has lost spark or if the injector has lost a pulse signal?

If you haven't, that is what needs to be done. What I suspect is happening is this. When the engine heats up, so does the ignition coil housing. Heat causes expansion when it comes to metal. I am thinking that the connection between the coil and coil housing for cylinder 4 is being lost. Recheck where they are connected to see if there is any excessive play or clearance.

See pic 1 below.

Let me know what you find.

Joe

See pic below.