I am having a hell of a time with my VX idling. I seem to happen when the engine is cold and start suddenly and occurs randomly. I get idle hunts when in neutral and in park. I seems to run great once warm. It is my daily driver. very short run to the freeway then 27 miles to work. Never a problem on the freeway. I put my ScanXL ObD II scanner on it and notice the following;
MIL Light Codes; P0171, P0172, P0174
absolute manifold PSI Max =14.9 Mean = 8.1 Min=2.8
short term fuel trim bank 1 Max=90% (sometimes at idle) Minimum=-21%
Long term fuel trim bank 1 Max=24% Mean=10% Min=1.6
Max Air Flow Max9.1lbs/Min Min3.8lbs/min
Fuel rate Max6.1gal/hr Mean2.5gal/hr

I have changed the IAC, cleaned the Throttle body, replaced the vacuum relief valve (mounted to the supercharger, opens when in idle to relief pressure back to uncompressed side of SC). I have re-installed the intake manifold to insure there wasn't a related vacuum leak.

There is a vacuum solenoid connect to evap canister with 2 hoses. I am not sure which hose goes on which end of the solenoid.

Well that's all the info I have. Hope someone can help.