I understand that a 3.4 lower intake manifold can be used on our 2.8. However, it won't have provisions for an iac inlet, cs injector, and both the csi switch and fan switch. I've converted over to the 7730, so the csi, fan switch and csi switch are not needed, but the iac inlet could be a problem.
My question is, if i route the iac thru the egr hole in the upper plenum (which is not being used), Will that work? Also, will any other lower intake manifolds work as well?
The reason I'm going this route is I've ruined my lower intake and our intakes are hard to find round here. The camaro and Firebird are plentiful in these parts.

A PFF memeber in Austria recently tried this, but the thread stops. You can probably find one in the mall.

https://www.fiero.nl/forum/Forum2/HTML/134490.html

Hi f85gtron!

the link from Gall757 is correct, the CSI delete and the IAC valve tube/pipe modifications for the 3.4L Camaro/Firebird LIM are not a big deal.

Yes, you can use the EGR inlet hole for routing the air flow from the IAC valve into the upper intake plenium.
But do not forget, to use a custom EGR gasket with a small 5 mm hole in the center.
If you use the stock EGR gasket, the idle speed would be too high at cold start!

Check out my old post from 05-06-2015 04:32 PM for more details (I have updated this post today).

[This message has been edited by Moar (edited 07-23-2015).]

I used a Trueleo upper intake with a 1991 Firebird V8 thottlebody and it has an IAC integrated into it. Plugged up the hole on the lower intake.
I realize that's probably not an option for you but just stating that for the record in case of future performance mods...

I have a stock 2.8 lower manifold for sale if you are interested.
Let me know.

------------------
===Always trying to find time to work on cars===
Louis Duet
Baldwin, Long Island, NY
"My mind spins like helicopter blades." -G. Rossdale
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Blue" <= '85 Fiero GT
3800sc series 2
~~~~~~~~~~~~~~~~~~~~~
"Boo" <= '81 Delorean DMC-12
VIN #5835
Stock PRV engine
Peugot 604 Intake manifold
Exhaust headers
Anti-3rd brake light

The reason the Fiero lower intake has the idle air tube going into the lower intake is to help distribute the fuel coming in from the cold-start injector. Since you're deleting the cold-start injector, you don't need to worry about that.

Using the EGR port for your idle air tube should work fine.

[This message has been edited by Blacktree (edited 07-24-2015).]