Thx for posting that image i been looking for it lol now i can give you a frame of reference, Based on that diagram it is the purge line that connects to lower right of the throttle body and runs down below the air cleaner housing and connects to canister. There is no vacuum on that line at all.

That is the next thing i plan on checking.


Update: I took the blazer to work today even though it is still hesitating but it is still drivable when needed. Was driving it for quite a while ( about 2 hours ) and check engine light came on suddenly and it started to idle kinda rough and the hesitation was alot worse then before when accelerating, I had 2 thoughts at that moment.

1) I could wait till i got home and scan it with scantool and see why light was on.

2) pull over and shut it off and pull ecm fuse for a bit and put it back in and see if CEL still stayed on or would reset.

I went with idea 2 lol and the light did reset and didn't come back on for the rest of my driving trip but the rough idle and worse hesitation remained. I got home and decided even though CEL was off i would see if there was still any codes stored that were thrown in ecm from the trip home after resetting CEL and guess what?

code 32 again! So apparently that used egr didn't work for long if at all to begin with. I mean when i put it in and reconnected the battery and test drove it a few miles yesterday in my previous update there was no code 32 but who knows if it was working 100% like it should either but it abviously isn't working now lol. I'm still thinking it is whats responsible for my hesitiation problem and here is why i think this and you can correct me if i'm wrong in my thinking here.

If the fuel pump or pressure regulator was bad or going bad it would run crappy all the time not just when it warms up would it not? Because when it is cold it seems to drive fine for a few minutes it is after it warms up it hesitates, And i'm thinking it is because when it is cold the egr isn't being opened or closed yet am i wrong here?

Is there any way i can bypass the egr temporarily by unplugging it or something to test my theory on if it still runs better without it to see if it is indeed the problem?

I don't want to run out and pay $170 for a new egr and still have same problem afterwards i'd like to be able to rule it out at least somehow.

 

Yes you can take the EGR off and block the port with a plate - allthough it is illegal to do so. Some guys just cut a peice of tin and use that tin as the EGR gasket to block the port. You will probably always have a code that way, but it would allow you to rule it out.

Make sure when you get your tune up parts that you get that 8 dollar harness I was talking about and solder it in... Opening that intake is easy with your 10MM deep socket. Its an easy change, and you will see how rotted out that rubber insert is.

EGR is only opened when cyl temps are too high. A cold engine has a closed EGR valve. When its warm and under load it will use EGR, but i dont think it opens when sitting at lights. You can test your EGR with a multi meter and the EGR in your hand. My EGR failed, and I grabbed one off an Astro van that worked just fine. New ones like 200 bucks so forget that.

How far in was the plunger going in? Mine went a max of about 1cm... If it doesnt go that far maybe there is some crap in the spring keeping it from opening all the way.

You asked about your temp sensor effecting performance... The one for your gauges is located on the pass side cyl head, above and between the 2 front plugs. Takes about a 15/16 to get it out of the head. Check that the wires are connected and not burned through on the manifold. This sensor is for your dash and wont effect performance. There is also one on your thermostat housing, and this CAN effect performance as all it does it take a reading for the ECM to adjust fuel ratios. Low coolant level can cause this sensor to make false readings. I have a leak in my rad, and when it gets low the truck runs poorly because that sensor is not wet with hot coolant cause the system is low...

 

The egr pintle went all the way in when i pressed down on it but on occasion if i repeated this it would not completely spring 100% closed all the time even after cleaning it really good i had to press it down again a few times and release it then it would pop all the way closed it would do this about 1-4 times of pressing it down and releasing it. That is what lead me to believe was the cause of the hesitation and semi rough idle because like you said at idle and stops and not under load it "should" be closed but i'm wondering if it isn't actually closing all the way and is just slightly sticking open all the time and causing problems. But i put in a used one off another blazer yesterday and the code 32 disappeared then thru the code again today after driving it and i reset the the ecm when i got home and started it back up and took it for a spin and tested ecm again and the code is gone again lol.

I am not 100% sure anymore that the egr itself is not working or not but maybe something else is malfunctioning causing it to not work right and throw the code 32 instead if that's even possible or the used one i put in was also bad i mean it did come out of a blown up motor with ALOT of miles on it so it wouldn't surprise me if it wasn't bad too. And i asked about the throttle body vacuum line and if it is suppost to have vacuum on it or not and if it would effect engine performance or the egr malfunctions if it doesn't. I have put a arrow in red to the one i am refering in this pic. When i got the blazer this line was removed and i reconnected it but it didn't seem to effect or change anything connected or not and if it IS suppost to have vacuum on the line there isn't any.


UPDATE 8/15/10:

Welltoday i finally got a "good" look at the plugs i had not really tried to look at them yet after getting this blazer and it appears to be the original plugs and cap/rotor and wires on it lol Went out and got all the replacement parts today but i'm dreading even attempting to get those plugs out there all rusted and probably going to be very difficult to get out now : / I'll update again after doing the work and let you all know how it goes.

 

Update 8/18/10:

Well i replaced cap/rotor and plugs and plug wires and i went with some NGK V plus plugs i am not too familiar with these plugs but was told they are not the "best" but there better then the cheap plugs so i hope there ok. The old plugs surprisingly looked pretty clean to me not black or oily or anything so it seems to me that is a good sign, The only thing i noticed is the electrodes on each plug were rounded off but other then that were clean the old plugs were SplitFire plugs so i was wrong when i thought they were the original plugs but they were still rusted pretty bad and appeared to be very old but apparently not lol. And the cap had a buildup on all the contact points. I'm sure i could have just cleaned it up and still used it but i replaced it and the rotor anyway just incase.

Sadly i noticed no improvement in the hesitation problem but i have now noticed that it runs and idles alot smoother and accelerates alot better with little hesitation but ONLY when it is cold once it warms up it idles a bit rough like there is a miss and the hesitation gets alot more prominent and there is still no check engine light coming on showing anything is wrong. So i plan to check the fuel pressure next as soon as i can get somewhere that has a gauge i can use to test it other then that i am running out of ideas of what would make it hesitate and run more poorly after warmup then it does cold.

But if i do discover it to be a fuel related issue like FPR or spider or fuel pump i'll just craigslist it and get rid of it i'm not investing the time and $$ into replacing all that on a vehicle with close to 200k miles on it i;d be into it more then it's worth.

If anyone has any other ideas that doesn't involve replacing a $200+ part i'm open to any suggestions any of you might have as to what's causing this problem lol

 

I am having the same exact issue with my truck. I have replaced countless parts including the ECM, Thermostat, Alternator, battery, FPR, distributor cap+rotor (and I had that whole assembly pulled and cleaned since it was rusted to hell and no oil was getting to it), IAC motor, and im sure a couple other things... The kicker is, my truck has less than 60k miles on it. It should NOT be doing this. And now that I'm in college it's going to be almost impossible to fix it on my time schedule. I will be following this thread very closely since this problem is 1 annoying and 2 embarrassing especially when you have to drive other people. Let me know if I can help out at all.
My mechanic is running out of ideas at this point. The IAC motor was his last ditch effort to attempt to fix it (i trust my mechanic very much). I have noticed with mine that if I disconnect the battery for an hour or so, the problem goes away for maybe a couple days, but then starts right back up soon thereafter (which is why I replaced the ECM). Almost as if it's "forgetting" the issue... Hopefully we can find an answer