Confused about IAC

August 10, 2007, 06:36:06 PM

Is the IAC only on EFI engines?
Would that be all Turbo Coupes, 87 & 88 5.0 and 88 3.8.

The IAC is often suggested as the cause of idle problems on CFI engines. Do any CFI engines have an IAC?

Confused about IAC

Reply #1 – August 10, 2007, 08:03:59 PM

The Ford Throttle Body engines use a ISC(idle speed controll)motor that actually moves the throttle lever on the TB... Was used on the 5.0 as well as the 3.8... Dunno about the sidewinder 4cyls... The 2.3 Lima never had CFI, went from carb in '86 to port EFI in '87..

Confused about IAC

Reply #2 – August 10, 2007, 08:51:54 PM

And The Lima 2.3 was EFI turbo in 83

Confused about IAC

Reply #3 – August 10, 2007, 09:27:15 PM

Quote from: ipsd;167812

And The Lima 2.3 was EFI turbo in 83

Yes, I failed to mention all the Turbo 2.3s has port EFI... Was actually Fords first port fuelie... And only, till it was introduced mid '85 on the 5.0 P/Us...

Confused about IAC

Reply #4 – August 11, 2007, 10:35:21 AM

Quote from: softtouch;167782

Is the IAC only on EFI engines?
Would that be all Turbo Coupes, 87 & 88 5.0 and 88 3.8.

The IAC is often suggested as the cause of idle problems on CFI engines. Do any CFI engines have an IAC?

for all general purposes, the IAC is an interchangeable reference to the same part as the ISC. On CFI ,, the ISC is fully exposed and you see what its doing (front driver side of cfi).
On 5.0SEFI, and 88 3.8L EFI the ISC (IAC) is burried up in the trottle body but its doing the same thing as the cfi setup.
if you take out the isc on a a 5.0 sefi, you will see an emmissions passage in there, thats where carbon build up occures.

anyway, ISC or IAC are the same. My shop manuals never call the sefi 5.0 engine an IAC, it calls it an ISC. Normally you only find the phrase IAC when looking up codes, you just have to be prepared to understand what they mean cause its abused alot.

its kind of like the ACT (air charge temp sensor) sensor has a couple different ways its called. ON the cfi 3.8, its not an ACT sensor although it is the same thing.