Found the Real Part number $$ 71.00 part number F2Pz-9F939-A for anyone that could not find it
Idle Air Adjust Spacer
Allow me to elaborate on the Idle Air Spacer for a moment. Coking on Ford EFI Throttle Blades has been a problem for many years. If the PCV or vent filter clogs, oil tends to back up and accumulate in the Throttle Bore and plate. This is also caused by blow-by from worn piston rings in older engines. The oil becomes a sludgy residue which eventually hardens reducing the expected amount of air that can pass by the closed Throttle Plate. As less air passes by the closed Throttle Plate, the EEC commands the IAC to increase air flow around the Throttle Plate to maintain a good idle. Eventually, the IAC will approach edge of it's operating range. This is the point where the symptoms of poor idle are experienced and Throttle Body/IAC cleaning are indicated.
To alleviate this problem, Ford developed the Idle Air By-pass Service Kit (F2PZ-9F939-A) for EFI Broncos prior to MY1991. The kit includes an Idle Air Adjust Spacer that corrects sludge contamination concerns on the Throttle Blades to the point that Ford no longer covered Throttle Body Cleaning under the 5/50 Emissions Warranty. A secondary benefit is the ability to fine tune closed throttle plate idle air flow without altering the TPS, which has been very popular with Mustang performance builders having idle problems. The Idle Air Bypass Kit was installed by Ford Dealerships under warranty per TSB 91-25-07 and is still available from Ford as well as aftermarket versions from Tomco and eBay.
Beginning in 1991, Ford began using a Sludge Tolerant Throttle Body design which includes a special slick Teflon coating inside the throttle bore. This coating minimizes deposit formation and does not require cleaning or the service kit. The issue is harsh cleaning can remove the sensitive Teflon coating eliminating the protective qualities. These Throttle Bodies can be identified by a black/yellow sticker on the Throttle Body warning against cleaning or adjusting. Please note that this Sludge Tolerant Design does not include the IAC which may still require servicing or replacement.
Cool post thanks, Miesk.yo, For DIY and to save $...
...had some 0.030" gasket material so I made my own with the same 1/2"
cut out. This gave enough bypass to noticeably raise the idle speed
-by Nelbur at Ford Bronco Zone Forums
The two holes in the plate are for bleeder screws, which provide a minimum
air rate adjustment independent of the throttle opening.
Yeah, -that's- what I'm thinking too, because not all of 'em have holes andDo all throttle plates have holes in them? My '94 does, and I wonder if Ford
knew that the IAC wouldn't be able to handle all idle conditions, so Ford gave
the throttle plates holes to help out.
Base Idle
The idle speed determined by the throttle lever setting on the carburetor or throttle body while the idle speed control (ISC) motor, or any other computer-controlled idle speed control device, is fully retracted and disconnected.
Curb Idle
Normal idle rpm. Computer controlled on many modern vehicles.