I think I found my problem, unfortunately, i found it after all the stores are closed. On the back of the upper intake manifold there are four vacuum lines. From the top, #1 and #3 vacuum lines are completely SPLIT down the seam, and i'd be very surprised if they hold any vacuum at all. I believe this may be the cause of my idle and misfiring misfortunes.

Where do these vacuum lines go? From what i can tell, one goes to the metal spider... and from the FSM it seems that one splits off into the PRCV/Relief rack and the other goes to i dunno what...

If someone could shed some light before i replace these tomorrow that would be great

 

pictures?

 

Except for the bottom one, those lines come from before the throttles, so no vacuum. They'll be leaking in unmetered air, so they'll have the same effect as a split TID for example. Bad idle.

 

Thanks NZ! where do they go to?

The actual 750 RPM idle is ok, its when i rev it up when it becomes a problem.

 

Oil injector air bleeds and fuel injector air bleeds.

 

Good stuff, thank you!