I totally understand your frustration with your Z. I am tempted to sale mine.I have been fighting with idling issues myself on my turbo z. I have replaced fuel filter(twice),New fuel pump,fuel pressure regulator,every vacuum lines and fuel line replaced,New pcv,air filter,timing. adjustment,New plugs and wire,New oxygen sensor,New MAF and Damn near an entire summer raking my brain. It's just sickening the money and time. Rebekahsz comment got me thinking about crossing over to the dark side(LS club).. I would like to go find out how hard the swap would be