EGR vacuum help

[jimi87-t]

**This is NOT a discussion on why or not to run EGR, all that has been discussed in detail before.**

Ok as some of you already know, I've been running a FFIM for some time now. But the EGR was removed and now I am getting the EGR back together. I have all the parts new from toyota, and have a couple of questions: (I have looked at the TSRM but some questions are not answered)

1. (I no longer have the stock TB) The vac port on the stock TB for EGR, is this feed before or after the throttle plate?

2. The EGR vacuum modulator, the top two vac ports are labeled "P" and "Q", which one is from the VSV and which one is to the EGR valve?

Thanks guys.

 

[jetjock]

1) The stock TB supplies ported vacuum, that is the port is located upstream of the closed throttle plate. The reason is to prevent EGR operation at idle.

2) Q goes to the EGR valve, P goes to the VSV...

 

[jimi87-t]

Thanks JJ, you're always a big help.
Just to clarify, vac is before the throttle plate,(as in no vac at idle) correct?

 

[jetjock]

You be welcome. Upstream means the air filter side. Downstream means the plenum side. Being on the air filter side means with the throttle plate closed the port will not be exposed to vacuum. That prevents EGR at idle. The VSV prevents EGR during other times...

 

[jdub]

I've wondered why Toyota did it this way...mechanical cut-off of vac at idle via the port. It would seem easier to use the ECU to activate the VSV when IDL is on.

 

[jimi87-t]

Great, thanks!