Modded Mustang Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
1,591 Posts
Discussion Starter · #1 ·
ok so i took off the new throttle body i put on ( 75m Mac) ...cleaned IAC...it still stays at 15-2000 rpm for like 1-2 seconds when i come to a stop...i have not tried removing the cruise control cable yet like someone else said...any other suggestions? I know Mac makes great exhaust products.... not sure about throttle bodys ...
 

·
Registered
Joined
·
1,591 Posts
Discussion Starter · #3 ·
how do i do that? i have an 04...with my manually? or with my tuner? i heard im not supposed to mess with that?
 

·
US Air Force (retired)
Joined
·
13,542 Posts
RPM hang is designed into our cars. I've been told that an inexpensive way to get rid of it is to install a custom IAC gasket. Go to Autozone and buy some gasket material. Take off the current IAC gasket and use it as a template for shape, size and bolt holes. Drill a smaller center hole for the IAC. Some have said 1/4 or 5/16. If the hole is too small you will loose your high idle. If the car doesn't run right just make the hole larger.

I learned of this mod after I bought a new TB/Plenum to get rid of the hanging rpms. It came with a new IAC gasket.
 

·
Registered
Joined
·
2,936 Posts
The idle "hang" while the car is rolling (at all), usually 1100 to 1200 rpm, is to keep the power steering fluid pressure up to ensure the Hydroboost brakes have enough pressure. It should drop off quickly though when you stop completely.

Did you disconnect the battery for 5-7 minutes when you installed the TB? That will clear the KAM and make the PCM relearn the idle air, and short and long term fuel trim, settings...
 

·
US Air Force (retired)
Joined
·
13,542 Posts
The rpm hang on my car was when I was driving normally shifting gears just around 2000 rpm. The rpm's would just stay where they were for a good two seconds and then slowly drop off. It drove me crazy.

The new IAC gasket that came with my BBK TB/Plenum ixed the hang, but rpm's still drop off slower than I want.
 

·
Registered
Joined
·
1,591 Posts
Discussion Starter · #7 ·
no i did not disconnect the battery for 5-7 minute...i will try that...do i have to bring the ecu back to stock before i do this?
 

·
Registered
Joined
·
339 Posts
take the cruise control cable off see if that works,solved the problem for me.
 

·
Registered
Joined
·
339 Posts
it's kind of funny because the most obvious thing,you will over look it,i sure did!!!!
 

·
Registered
Joined
·
468 Posts
my car had a very high hanging idle for the first couple days until the computer learned the new setup around 2000
 
1 - 11 of 11 Posts
Top