I need help trying to figure an 87 TPI internal plenum passages. Is there a drawing that shows which passage is the EGR and which is for what I think is air for the idle circuit. There are two ports in the floor area and the triangle shape port on the TB flange. I am blocking off the EGR tube and want to get it right thanks in advance.

 

the feed for the egr starts at the passenger side head and goes into the center of the manifold to the egr. From the egr the exhaust gasses go out the manifold on the passenger side through the rh runner small tube. When this passage enters the plenum on the rh side it y's and exits behind the throttle body blades on the plenum floor. The iac passage is in the center of the tb and goes to the iac and out the back of the iac tb. Why don't you just use a egr block off plate or tap in a expansion plug in the rh side runner tube.

 

Ok I have fab a plate to block the EGR the after market manifold that was shipped with both left and right small tubes rtv'd. When assemblying the plenum I noticed the both ports were sealed. I am still on the learning curve with EFI this is my first.

 

Don't forget to deactivate the EGR system in the chip programming. Earlier TPI engines that used a Mass Airflow Sensor had a temp sensor that screwed into the EGR valve to confirm hot exhaust gasses were actually flowign through the valve when it was commanded to open by the ECM. It'll quickly figure out the system has been defeated and throw a Check Engine light without turning the EGR system off in the programming.

 

the 85-89 tpi's had the problematic egr temp switch (code 32) The egr is commanded on off mat temperature. you should make this change in code.

 

Sorry I did not mention that I am using a 1990 MAP computer with a pre-1990 plenum and runners that's why I was concerned about the passages in the runners. When I recieved the manifold both of the small tubes were plugged? I actually drove it that way for until recently