I have a 86 IROC-Z28 305 TPI.I was checking my vacuum lines and there doesn't seem to be any vacuum to the line under my throttle body that go's to my EGR and My EVAP canister.Does the vacuum start under pressure? I got the car hot and then took the vac hose off the bottom of the throttle body and there's no vac at all so I really don't think that my EGR is opening...

 

Under the conditions you describe, you should not have vacuum. You SHOULD have vacuum, however, when the ECM commands the EGR Solenoid "ON". Trace that vacuum line back to the solenoid, and then check the other vacuum line at the solenoid. That should have vacuum. The ECM will command the solenoid when conditions are right.

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South East Thirdgen


ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
Ported Plenum,
TB Coolant Bypass,
SSM SFC,
Boxed LCAs,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
KYB Shocks

'97 Bonneville SSE

 

There's no vacuum going to the solenoid at all,so if the ECM open's the solenoid to get vacuum to the EGR there is none.As far as I know there should be vacuum to the solenoid at all time's and the ECM tell's the solenoid when to open to give vac to the EGR.But under the throttle body there is no vacuum coming through the line to do that...Thank's for the help

 

If you don't have any vacuum at the solenoid, than you need to trace the vacuum line from the solenoid to the manifold. Chances are the plastic line is broken.

To learn more about EGR, check out EGR

------------------
If you live in Southeastern US, check us out!
South East Thirdgen


ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
JET AFPR,
Ported Plenum,
TB Coolant Bypass,
SSM SFC,
Boxed LCAs,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
KYB Shocks

'97 Bonneville SSE