TPI EGR Question
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 2,938
Likes: 2
From: Arkansas
TPI EGR Question
Does anyone know if the vacuum port on the bottom side of the stock throttle body is a continuous source or a timed source? I believe the EGR vacuum line attaches to it.
Thanks again!
Thanks again!
Race Director
Joined: Jun 2004
Posts: 13,980
Likes: 710
From: WI
What year? I have had the TB on my '88 all apart a few times. The passages are all always flowing. I am not sure what timed is. From what I remember, the bottem fitting goes to the passenger side V/C as the PCV draw, the other fitting goes to the evap system, over to fittings by the drivers side front. My car has a vaccum diagram on the radiator and even the cheap service manuals have them. Maybe someone else will chime in with a picture.
Race Director
Joined: Jun 2004
Posts: 13,980
Likes: 710
From: WI
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 2,938
Likes: 2
From: Arkansas
What year? I have had the TB on my '88 all apart a few times. The passages are all always flowing. I am not sure what timed is. From what I remember, the bottem fitting goes to the passenger side V/C as the PCV draw, the other fitting goes to the evap system, over to fittings by the drivers side front. My car has a vaccum diagram on the radiator and even the cheap service manuals have them. Maybe someone else will chime in with a picture.
Team Owner
Joined: Jan 2003
Posts: 20,342
Likes: 264
From: Summerland B.C. Canada
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 2,938
Likes: 2
From: Arkansas
I guess I could tee off one of those lines, I figured I could use the egr port since it's blocked off right now anyways.
Melting Slicks
Joined: Aug 2004
Posts: 2,934
Likes: 235
From: Oakbank Manitoba
The EGR Vacuum port on the bottom of the TPI throttle body is a timed port. It only produces vacuum in the off idle position (throttle blades open). You don't want to use it. Tee off the fuel pressure reg. port as I believe the Map sensor requires its own independant vacuum connection. Just as a note.....the LT1 throttle bodies do not have this EGR port. The EGR is timed by the ECM software only.
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