Well for the longest time I've tried to figure out why my truck hasn't been starting right... What did i have to do to get it started?
Fuel pressure: Perfect
Compression: Not to bad, 110-130...
Ignition: Changed distributor, rotor, cap, wires, spark plugs...

I would have to crank the crap outta it and sum times hold the throttle wide open!

All this hassle and for wat!!! A simple valve.....

An Idle Air Control Valve! go figure eh??? the littlest thing ever.... What else did i find out??
The sensor is used in a 3100 too... crazy... depending on your motor type! the new plastic style wont work from a 3100 but guess what will work from? a 305 or 350......
Mines a 95... See the valve closes a whole in the intake to reduce the air then when started and starting to get warm, it opens the whole up to let more air in.. To me... Its like a freeking choke..... Simple enough to explain? Duno where this part is? well on mines its behind the throttle cable on passenger side, If looking at the motor.

I know this might be your case... But check it out.. its pricey brand new or go to a scrap yard.. or get your vehicle running, have it out. 2 T25 bolts. cover the whole with sumthing thick cuz its gunna be loud as heck.. and see if you can see it moving... if not, dump it into some diesel and let it dry out, try checking it again. If its working now or has been whole time. Well... Check the goofey crank sensor in your distributor if you haven't changed it yet. I could get mine started but timing light on each cable showed a miss on drivers side only and not passenger changed and problem fixed.. If you dont understand reply here and i'll try to help... If this fixes your problem.. Rep??? XD

Edit: I forgot to mention i have the 95 style not the 96+.. The 96 and newer work from a 305 or 350. Not sure if theres any cars you can steal it from and will work. The bolt pattern for the 95 and 96+ are different.

 

isnt that the evap purge thingy if not it looks exactly like it lol

 

Nope, that is the IAC valve. If this isn't allowing in the proper amount of air, it can cause a no start/stalling issue. But that condition could be circumvented by opening the throttle manually with the pedal as stated above.

 

could that also kill the engine while driving?

 

Well, I have had it stall with this problem before. So yes, the IAC will make it stall especially while under load.
But my first blazer I have had it stall because the fuel pump was getting to hot. and starting to go. The indication of that though was really loud from the tank... Theres also the case if the vehicle is just running weird in idle, my egr's kept getting carboned up, never making it fully stall though.

 

The IAC valve should not cause it to stall if off idle (pretty much any throttle location other than closed). The PCM should recognize that there is more air going into the engine than the TPS position should be allowing and adapt.

 

That is true, But what if it wasn't opening to let more air in. there for flooding it? Im not positive, but when i put it into drive and stepped on the gas, it was bogging out hardcore and being under more pressure for the torque converter... Hense more lag on the motor causing it to stall....

 

It shouldn't. The primary sensor on the intake side is the MAF sensor. The MAF will read the increased airflow and should account for it.

 

I guess my blazer is a lil messed haha.

 

Actually, I just put your screenname to what you are driving. Being that the 96+ trucks comprise the majority of the 2nd generation vehicles and that I didn't see what you were driving in the post text, I assumed 96+. Sorry for that.

'95s didn't have a MAF sensor so it is possible for what you were describing to happen. Still, the ECM should still notice that there is more airflow (lower manifold pressure) via the MAP sensor than the throttle position should allow for and compensate, but this happens slower on the CPI engines because MAP output isn't as instantaneous of a reading as the MAF output.