Throttle body question??

[Vettedrmr]

Pulled the throttle body off my son's '92 S13 today, and found small port that is just upstream from the throttle blade when it's in the fully closed position (i.e. the air filter side, not the vacuum side).

Anyone have an idea what this port is for?

TIA, and have a good one,Mike

[s13rb25det]

im pretty sure it is for the engine to idle when throtle is not open. not quiet sure though.

[Vettedrmr]

I don't think so, because it's upstream of the throttle body and is way too small (looks like a idle fuel port on a carburetor) to flow enough air to idle the engine.

Thanks for the reply, and have a good one,Mike

[Vettedrmr]

Could it be the vacuum source for the EGR valve?

[ka-t4u]

i highly doubt that it has anything to do with idle, as we all know then it wouldn't make sense to have an idle control valve, and i also doubt that it is for the egr because all the egr crap its on the back of the manifold/engine

[Vettedrmr]

The reason I was wondering about it being the vacuum supply for the EGR is that it is JUST in front of the throttle blade when it's fully closed, and the original vacuum line *did* run to the back of the engine.

The guy that rebuilt the engine for us is faxing me the vacuum info from Alldata. I should get the fax in the morning; I'll let you know what I find.

Thanks for the reply, and have a good one,Mike

[corn322]

From the FSM, just as Vettedrmr suspected:

[Vettedrmr]

That's it!!! I'd dug around and found drawings that kinda inferred that was the routing, but your diagram locks it down.

Thanks for the info, and have a good one,Mike