is it still funning the stock ECU??? If so do an error check on it adn see what it says, you can grab a manual off the net or post up what lights flash and I can find out what the ECU is saying is wrong.

Have you pulled out your spark plugs and checked them?? cleaned them or replaced them?

What happened when you disconnected each coil pack one by one? did the engine almost die when you checked everyone or did one not cause any difference??

Have you got a vacuum guage? It will tell you if there is a vacuum leak somewhere in the system.

Check the vacuum line to the fuel rail is in good repair or hasn't came off by accident.

When you say it runs like ####, does it cough and splutter? Miss or make funny noises etc?

Whent he engine isnt' running pull the CAS out (thats the round thing on the cam cover and then turn the ignition to ON then slowly spin the shaft attached to the round thing you just pulled out, this will make the injectors fire (so it's best to disconnect your fuel pump so it doesn't fill your engine up with fuel. Listen carefully to each injector does it "Click"??
The CAS is a prick to put back in it's keyed to only go back in one way so don't worry about that my trick to get it back in is wiggle it, remember to mark where it was before pulling it out as this is what sets your timing.

Pull out each coil pack and if you have a spare spark plug hook that into each coil pack and see if it sparks when you earth the plug this can be done when the engine is running (if doing it when the engine is running it's best to use a spare that way you don't have fuel and crap spraying out. It will fire when you pull out the CAS and test the injectors as you are simulating the engine cranking over.

Ummmm try all that stuff 99 times out of 100 it tends to be a spark issue as the fuel system is very simple.

Cheers
Damo