KED85

I can kick myself for not doing this when I swapped engines, but I didn't know.
I see the 4 screws holding the IAC set up on my 1985 throtle body. I see a gasket. I see a plug on the end of the IAC in the throttle body housing.
I recall Tom mentioning that remove the unit, spray carb cleaner (downward), on it, to clean off carbon build up. Should I remove the unit (unscrew it) from the housing? Would it look like one of the fuel injectors I swapped?
Should I remove the entire assembly (off the throttle body), disconnect the wiring plug on the back to clean it more throughly?
I hope not need to replace the gasket, by doing this necessary job.
Thanks for the tips!

Oh, can't figure out what to do with the Camaro air cleaner assembly I bought. Tried several ideas, no luck yet. Thinking of chopping underside of the hood to make it fit, tho. That may not be the right path, either. We would weld back some support under there.
Bummed , but not defeated!

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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

TomP

4 screws, eh? That's odd. My '86 IAC screws into the TB like a spark plug does! My friend's '89 and other friend's '87 are the same way. So it seems like '85 had the mounting flange, and the 3.1's had the mounting flange, and the '86-'89 2.8's had the threaded IAC?

Anyway... yeah, with the car off, unplug the IAC motor. I've always re-used my gasket (it sticks on the TB), you can probably make one out of regular fiber gasket material. Next, remove the IAC from the TB. You'll see at the end an arrow-shaped pintle, and a spring on the shaft of the motor. Hold the motor so the pintle points down, and spray it clean. This way no fluid goes inside the motor. When it dries, lay it aside. Remove the TB hose. Spray cleaner into the IAC-end of the TB (there's a small hole the size of the pintle there). You'll see a ton of carbon flow out of the front of the TB, from the hole directly to the passenger side of the throttle blades. The IAC passageway in the TB usually gets dirtier than the pintle. (The hole is in the side, in that "C" looking part.) Then, put the IAC back in, and put the car back together.

It's important to never have the IAC plugged in without being inside the throttle body! If this happens, the computer will energize the IAC, and move the pintle outward further than it should be. This could even pop the shaft off the motor. You then have to fight the motor itself to (re-insert the shaft and) wiggle the pintle/shaft deep inside. Otherwise, you won't be able to seat the IAC inside the TB- the pintle will be extended too far. As long as unhooking the IAC's connector is the first thing you do, and pluggin the IAC back in is the last thing you do, you're okay.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

Graeme'sFirebird

Nope....mine screws in like a spark plug too , 89

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1989 Firebird
2.8 v6, t5 swapped in

Ram Hi-po clutch, Cold Air, 1.6 rockers (ready to install), Lakewood LCA's, Lakewood Lift bars, Wonder Bar, 3" y-pipe, Random Tech Cat, 3" I-pipe, Flowmasters, MSd 6a, MSD Coil (Fireball in future) Accel 8.8 wires, MSD Ignition Module, 4th Gen Seats (not front yet)

" I'd rather run last in a full out race, than to NOT run at all ".

CaliCamaroRS

hmmm, i've never seen that. mine bolts on to the throttle body with 2 screws i think.

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Dan
1990 3.1L RS
80 Series Flowmaster
It's fast(er than a 3 cyl metro)

KED85

Ok
I saying this wrong.
But, I got my answer.
Lemme xplin
i see the IAC, yes, it's a spark plug shaped item. Yes, I NOW do understand that it screws unscrews.

I assumed you remove the 4 threaded torx screws to access the unit, clean it that way.

So, Unplug, remove, spray clean, wipe, reinsert connect plug assembly.
The Hose part, I see, also.
I spray down inside that hole and that clears it out?
Ok
That IAC is a motor? Or a variation of a fuel injector pintle, it moves up & down to add fuel, as needed.
THANKS SO MUCH!

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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

86Chicken

The IAC adds air not fuel. The motor moves the pintle in and out to block or open an air bypass so the engine can get enough air when the throttle blades are closed.

Just making sure we are all on the same page.

Dale

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The Bird
1986 FireBird
2.8L MPFI
Gutted Cat, No muffler (Sweet Sound)
Was 700-R4 --> Now T5

[This message has been edited by 86Chicken (edited April 23, 2001).]

KED85

Dale, way cool,
NOW to add confusion...
Why the carbon build up?
I assume the fumes from the EGR set up?

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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

86Chicken

As far as I know the carbon is from the EGR. After all, it is tossing exhaust into the TB.

If anyone else knows I would be glad to find out for sure.

Dale

KED85

that answers why the build up behind the throttle body blades
thanks
how easily does the clip holding IAC break?


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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA