Check your fuel pressure in the rail, also.
A compression test may be of some help to you, too. It may be that you have a sticky valve or a leaky piston ring, or even worse, a blown head gasket. Try having the vehicle scanned at an Autozone or local shop for a code reading and tell us what the code is. I?m assuming you?ll get a P0304 which is a Cylinder 4 Misfire. Ah, and the blinking MIL lamp indicates that there is a misfire that is capable of damaging your catalytic converter. Dumping raw fuel into the catalyst is not so much a good thing :P
"bob_in_stpete" wrote: > My Crown Vic recently developed a miss on the #4 cylinder.I > have > changed the plugs,and wires.It still has the miss.I checked > the coil > pack and the Fuel Injector and both are good.The check engine > light is > steady from idle up to about 40mph.Above 40mph and the light > blinks.Any ideas what the cause might be?