Persistent P0301 Code HELP!

[terby]

1997 Saturn SW-2 1.9L DOHC.

I need help diagnosing a P0301 (Misfire in Cylinder 1) code. The SES light is on, sometimes solid, sometimes blinking. The engine is misfiring OR partially firing, especially noticeable under load (uphill, quick acceleration).

Things I've already done that did not affect the problem at all:
*Replaced all plugs and wires, NOT using platinum.
*New fuel injector and swapped fuel injectors.
*Swapped Coils.
*Replaced what I'm calling the injection module, the electronic platform that the coils plug in to.
*When I simply unplug the spark plug wire to cylinder 1, the miss gets much worse, so I suspect the cylinder is firing but something is off (not enough fuel or air? spark at the wrong time?)
*Unplugged fuel injectors one at a time and watched them spray fuel.
*Taken it to two mechanics, one of whom told me I had a blown head or head gasket (neither was true). The other told me I had blown rings, and since the compression in cylinder 1 was 120 compared to 160 in the others I REBUILT THE ENGINE. Compression right after rebuild is 180 across all cylinders. THIS DID NOT FIX THE PROBLEM.

The only thing that makes any difference in the problem is when I switch the number 4 coil to the number 1 plug (and the #1coil to the #4 plug). Since this model uses a waste spark (spark after exhaust stroke) this should have no effect on the operation of the engine. It did however give me the code P0304 instead. If the ignition module is the sensor giving me the code (which it may be, since it also acts as the cam sensor) then this is not surprising. If some other sensor is giving me the code then changing those wires changed the cylinder that is misfiring and that might help locate the trouble.

I suspect this is an electronic problem, something electronic is CAUSING the misfire. However, since NO other codes have come up I don't know where to look. As a symptom, my mileage has decreased from an average 32 mpg down to 20 mpg. Power is greatly decreased (duh).

Any help would be appreciated. If any more information is needed let me know and I'll put up what I can asap.

[terby]

meant to say IGNITION Module above, ICM, not injection module.

Would a crank sensor error show on only one cylinder? A friend suggests that the knock sensor could be incorrectly reading a knock and trying to compensate. Suggestions?

How does the computer register the code P0301? What sensor is detecting the miss?

[OldNuc]

Have you replaced the plug wires since playing the pull a plug wire game? If not, then do so. Check the cold temperature secondary resistance of both coils. Let them sit overnight in the air conditioned house and then check them. 8k ohm minimum resistance.

Verify the wire routing... The routing is critical and it does make a difference.

Ignition wire routing as seen when looking at the engine and coils from the front, hood open, your left to right.

Engine
1-2-3-4

4-1-2-3
coil towers

Connect the matching numbers with a plug wire. The #1 and #4 plug wire must be in wire clips and next to each other from the coil to the cam cover clips.

Exactly what brand of plugs are you using?