Hello everyone and i thank you now for your advise and time you take to help me try and solve the many problems i have with this truck. Oh its a 1996 chevy blazer 4.3 vortek 128.000 miles 4x4

Issue 1. A few months back i did a tune up on the truck after i did the tune up the truck began to act like it was going to die as it sat idle which was around 500rpm.

Issue 2. Well i think its a continue of issue one but now the truck jerks and sputters then dies completely if i don't keep it rev'd to over 2k rpms. So its been sitting for the last 3 weeks

Issue 3. So i had to drive it today and when i got in my brake pedal was hard as hell to press and i could hear Air when i pressed it. Now i think its my power brake booster but once again i am clueless and could use some insight on these problems.

i have more issues but these are the most immediate that needs tending too.

 

sounds like a vac leak check the line going to the booster also there might be a vac line going into the intake check if that's leaking also if you have 1

also when you did the tune up what brand products did you use

 

check your vacuum hose to the brake booster first... look for cracks or possibly it completely off...

damn, beat me to it...
what he said ^^^

 

if you did not use delco tune up products-i.e. cap/rotor then id suggest go to the part store and get them. Auto Zone does NOT sell delco, but Advance Auto does.

If you DID use delco products then the culprit could most likely be a vac leak at the intake.

Brake pedal stiff sounds like the booster.. probably just a line cracked and needs replaced. Worse case scenerio is your entire booster went bad. Have you checked your fluid for the brakes by chance?

 

To those who replied thank you, well i checked under the hood this morning i did find one of the lines comes off the Air filter that goes into the left valve cover off so i put that back on and it did die when it was at Idle but it still has a super rough idle feels likes it wants to die also something i forgot to mention is it is running SUPER RICH i mean you can spell it from a very far distance. The Power Brake Booster Vacum line was intact and looked to be in good shape it wasn't dried up or anything so i moved it around very flexable. Fluid was abit low but well within limits the rubber seal did seem to be abit dried up around the edges. So i am guessing its the brake bosster thats bad.

 

I've had several booster apply seals go bad.. hissing when depressed, bleeds off vacuum when depressed to point of hard pedal in one... None caused bad idle, except when depressed. Had ONE where the manifold side seal failed.. that caused bad idle.
Simple.. block off line to booster, does it get better?

Super rich is a whole different problem. Glad you remembred that little detail.

Fix that first. Pull oil filler cap, sniff.
do fuel pressure check.
Read the spark plugs.

 

Well i have looked over all the vacum lines and couldn't find anything wrong with them. So after put the ling back on intake that seem to come off i was out ther messing with it today and notice that the hard brake pedals doesn't stop being hard but the car smooths our as it still running really rich and rough. A few moments after i take my foot off the brake pedal it seems to drop RPM below 500 and gradually goes back up until it is back up to its normal idle but still rough which is around 700-900rpms

 

*Moved to '2nd Gen Tech'*

 

egr valve stuck open 99.9 percent sure. if u wanna test to see if booster leaking, clamp off the vac line going to it and see if idle will steady. on the valve, try starting it up and uning a long half inch extension wack on the base of it and see if itll close. u can take it off too and push plunger back in by hand to see if it sticks open, should fall shut fast and smooth