Well i still have my issues regarding my crapO '95 4.3 Blazer
whats been replaced thus far: New
-Sparkplugs (including cyl#3),rotor,distribute,Sprk-wires
-IAC,TPS,EGR,PCV-valve&cleaned entire Manifold(sooted up!)
-New CPI/spider/regulator,poppets ( frigg'n $800)
-Fuel filter,injector cleaner,good gas
-New Cataylic convertor & muffler


Symptoms: runs a h*ll alot better when starting after putting new CPI assem,but still shakes r-e-a-l bad at idle/misfire/sounds like it's gonna stall(never does though),and suddenly rev(foot no where near throttle)
So what does the guro's think i should spend the rest of my retirement savings on..feul pump,coil..Or..

 

Sure sounds like a vacuum leak to me.
Before you spend another $1,000 maybe spend $100 for a diagnostic cheak at a reputable auto shop.....

 

i dont know if its the same for a 95 blazer, but maybe you got carbon stuck in the EGR valve?
that would cause the rough , fellin like its gonna stall, idle

happened a lot to my 94

 

As written, it is brand spanking shiny&new!(EGR)..i really,
r-eall-y feel reluctant to get it diagnosed again,as last time the only shop in town says it was the..(gasp) starter,charges $700 parts/labour, and when i go down to inspect they're work i find one of the bolts holding starter on, 2" clearance from any contact to starter..as you can figure i'm pretty much on my own in proccess of elimination,unless i drive 2hrs to the next nearest town,uggs!
I was thinking next, to just risk it and spring for a new MAP-sensor.

 

im not sure. i replaced everything you have also, and it ended up being just a piece of stuff, stuck in my egr valve. i just took out the egr and took the piece of stuff out, you know? this was the day after i bought and installed the new egr.

wish i could help more...
id go with what chevy lover says and check 4 a vaccum leak

 

Well it's off to the stealer-ship..again..on the 30th. It sure does have the symptons of air leaks with it's up and down idle lopings.

 

[hr][align=left]i am goin through this same problem as well,..replaced iac valve(was frozen),fixed vacume leaks,lopes at idle like its a nasty cam.off idle its fine runs good,except occasionally it will surge while cruzn.40 to45mph.
after fixn the vacume leaks it now wont idle while in gear(auto trans)aft coming to a stop.no codes as of yet.
was unable to pull codes be fore,i resset vcm by diconnecting battery for 15 mins or so.(wanted to start fresh if any codes kick,since i been disconnecting stuff to see if theres a diffirence) im now able to get the 12 12 to flash,finnally,so now im waiting for a code.runs like sh*t & still no codes.
does sound like map senser,but.....
any help would be great.
thanx
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I sympathize heavily along side you evil95!
Could you say where exactly you played around with your
vacum-leak(s)?
You may(only may) want to consider opting for a new EGR-valve then perhaps aCPI/Spider assembly(very expensive buggers$733here in Canada)
My '95 'now' starts sooo much better but, the throttle lopings up?downthroughout the idle/entire driving range in very present still.