On the bottom of the throttle body there is a small brass port where a tee comes off of it, one hose going to the charcol canister and one going to the EGR solenoid if I'm not mistaken. Question: Should this port have vacumn on it at all times when the engine is running? I have no vacumn currently. Also none at part or full throttle. Pulled throttle body and all passages clear. Same for all hoses. Keep getting Code 32 (EGR) and feel that my EGR solenoid is not getting vacumn. Since this is an OEM hookup for vacumn can anyone tell me why now no vacumn?

 

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Does your cruise work?
I haven't seen the vacuum routing on an 85 tpi but on 88's and up the cc vacuum supply does not come from a "t" on the bottom of the tb. It comes from a check valve hooked to a port at the back right of the plenum.

 

The vacumn I am talking about is a small plastic hard line that goes to the EGR solenoid and to the right side of the charcol canister. According to my GM shop manual there should be at least 7" vacumn at this "ported Vacumn" nipple at 2000rpm. Currently I have no vacumn and have pulled throttle body,checked all lines,made sure everything is clear. Seems strange that the vacumn just disappeared. My cruise has a seperate line that comes off a tee at the vacumn resevoir. Believe me,I have checked everything.

 

That port on driverside under the TB is for the egr solenoid, it shall give vacuum when throttle is given, and then the EGR dutycycle starts. When the throttle is off the there shall be no vacuum (or almost none) maybe you got alot of dirt in your TB try cleaning it out, there are really really small passages in the TB, I just cleaned my out 1 month ago..

Because the EGR is only active when moving and giving throttle..

 

I removed the throttle body and checked all passages. They were spotless. I blew through all hoses and they were clear. Put vacumn guage on nipple at bottom of TB and zero vacumn, even when bringing up engine speed to over 1500-3000rpm's. I've done everything possible,including removing top cover of TB and checking for a restriction there. It's like the TB just quit producing vacumn at this port. On the passenger side of the TB where the vacumn line goes to the left side of the charcol canister there is 22"vacumn at idle. Any ideas?

 

Did you ever figure this problem out? I have the exact same problem, and have tried everything you did!

Thanks in advance

 

The port on the bottom of the throttlebody is a ported vacuum signal. If you are having a code 32 for your egr you should follow the fsm trouble tree.

 

Thanks a lot I will try this!