i recently bought a felpro tpi upper gasket set and the throttle body gasket that came with it is different from the one the car has on there now. the one the car has is open around the iac passage to behind the throttle blades (causing a vacuum leak sorta?). the one included with the kit has a sealed triangle shaped opening. maybe my car has the wrong one and has been causing my idle/iac system to act funny. freaking nearly 2000 rpm flare up upon start. my iac(new) and throttle body have been fully cleaned and lubed.

the setup in question is my 88' 350 tpi. here's a pic of the gaskets.

 

Use the one on the right

 

yeah i went ahead and used the one on the right. what the hell is the other used for? earlier models? or was the gasket re-designed????

 

my felpro kit came with 2 of those as well.... i used the one on the right...

 

The one on the right is what you need. My gasket set was the same.

 

i use the one on the left...no problems

what year are your cars?...

mine is a 91

 

Mystikkal does your car rev up to like 2 grand when started and then slowly work it's way down. Mine does this same thing and I am curious as to what is going on with it. -John

 

yes it does/used to. well now it flares up to about 1500 sits there about two secs and then begins to slowly come back to normal. it does this more often when the car is hot and has sit only a short while. ie 10-20 mins. it doesn't do it cold.

then at other times it just goes to about 1200 and goes back down normally?

 

This is "normal" for these cars. Mine has done the 1500-600 on start since it was new. I think it has to do with the starting fuel and IAC steps on start, I'm sure that with some fine tweaking with the prom code you could eliminate it.

 

I am gonna start a new related post so I don't steal this one so please read it guys.