so last night i decided to start up the buick. mods are l26, ported gen 3, 3.3 pulley, xp cam, n*,lq4 maf, 42.5#'s, headers, al103's, built trans, hp tuners. it seems like every cold start up it idle around like 450-500 rpms. it also seems to do this when its rainy out. i have to give it some throttle to keep it idleing at 900 and running good. if i slowly get out of the throttle it is fine only until i tottally let off it then it idles around 450-500 rpm and struggles to stay running. while its doing this the a/c clutch kicks on and off alot and the power surges and lights dim out, cause the idle is so low. the idle in the pcm is set at around 1100 rpms for cold start and fully warmed up at 750. now i believe i have it narrowed down to a few things. could it be the iac on the n* causing this? how many ppl drill an 1/8" hold in the throttle plate? can that help me out? also one last idea. my a/c clutch has been screeching since last summer so i keep it on defrost so it doesnt make the annoying screeching sound. i never pulled the belt yet but could a bad bearing in the ac compressor cause a the low idle by pretty much holding the serp belt from spinning?? i hear no grinding only wehn the idle is low it sound more like chugging from the belt area.. any ideas?
