Update on bad idle 5.7

[fuzzypuppy]

Well started from scratch as i stated last post, started with the IAC, 'just installed new, cleaned seat, reinstalled as per haynes recomendations, performed thier basic check, everything good there.
performed the meter check on my TPS as per haynes, all's good there.
checked distrib cap and ohmed wires, all's good there.
layed across my motor put my face right in the TBI and opened the butterflys, clean as a whistle, "I had the TB off about 6 mos ago and throughly cleaned during a cam/timing chain change.
Checked ALL vacume lines throughly, found the charcoal canister and egr lines switched at the TB, put them in thier proper locations.
crappy idle still there, as well started a little stumble at light throddle, i attribute this to egr since when I disconnect egr this disapers.
still have to check, the new temp sensor, the new o2 sensor,knock sensor, and egr 'once i get a new vacume pump', have a new fuel filter to install as soon as time permits, though i dont think this is causing my idle problem,
working 14 hr days and my father in law passing away couple of days ago and my free time went to ZERO.
Since the recent install of my new tach i can at least now see how low the idle goes and how irratic it gets at times, on a hot day in traffic, LA traffic. it bounces between 5 and 600 rpm, literaly bounces, brand new sunpro tach, dont know how accurrate they are but the bouncing itself gets me wondering.
after the final sensor checks if i still have the problem ive got a feeling i better start checking on the ignition componants, as well as timing compression etc, since as i said i have gone through the sensors before and this is just a recheck, ya never know though since i checked vacume lines already and missed the crossed lines untill my recheck."nobodys perfect"
just found out a "friend of a friend" has a scanner and may resort to paying for a check if all else fails. this has turned into a quest, imna find the problem if it kills me, the saddest part for me is this is causing me to get into the $ i had saved up for a decient set of headers since my dr side manifold is cracked. lifes a beach huh. and still have as yet to find anyone who has actually posted a solution to this obviously common problem on any boards ive spent countless hours checking. though i really hope none of ya has to go through the stuff i'am. and to top it off i've got a nice set of vortecs sittin in my garage that i see no reason to bolt on till i find this nagging little problem.i think im starting to sound like one of my grandpa's stories about walking to school in the snow up hill both ways.lol thanks all

[greg0380]

I had a problem with an old EGR valve once that wouldn't close all the way and acted like a vacuum leak, gave an erratic idle. Have you tried removing it/cleaning it or fabricating a block off plate just to test. Your EGR sounds like my old one and gave stumbling at part throttle, after replacing it, problem solved.