where are all possible vacuum leaks on 94 z28 ? does anyone know

 

egr
air

 

the air pump can cause vacuum leaks? i plugged the air fittings in my headers but have not removed the air componets could this cause a vacuum leak

 

it could if you haven't unplugged the air pump itself...

 

I havent gotten around to unplugging it either, so i problay would be having some type of vacuum leak

 

Check for leaks around the elbow between the throttle body and mass air sensor. Mine was throwing codes from that. Also visually inspect all hoses on both sides of the intake manifold for any dry rotting. If they appear cracked just go to the dealer and order some new ones. I had to replace a few myself. They dont cost much at all.

 

Lets see:

brake booster
EGR
opti vacuum (if 95 & up)
PVC
EVAP
HVAC mode control
fuel pressure regulator
AIR purge valve (if you have had the recall or are late model). The actual pump side of the AIR system is not going to cause any vacuum leaks.
Poor injector seals
MAP sensor seal

Those are aside from the intake manifold or throttle body having any sealing problems.

 

is the pvc suppose to move freely in the intake manifold i mean its like nothing to just pull it out of the intake

 

It should be snug enough to seal. There have been reports of non AC-Delco ones that are not as large in diameter and do not fit tightly. That might be your problem or the grommet has just shrunk with age.

 

I think I have this problem. Mine wiggles a little and leaks a little oil I believe. I don't know if it's causing a vacuum leak though.