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Oct 30, 2008 | 03:09 PM

#31

cliffyk

TECH SAVANT

Joined: Dec 2006

Posts: 10,937

From: Saint Augustine, FL

Quote:

Originally Posted by cisurfer

ok so this is pissing me off, my stang will be fine on startup but a mile down the road if put it in neutral my rpms will be liek 2k sometimes 3k and when im at a stop its like 1500 rpms...i thot it was a bad IAC becuase when i unplugged the IAC and set my TB screw i had it idle normal and drive normally the check engine light just came on cuz it was unplugged, i replaced the IAC yesterday and the same thing is happening again...what could it be

The "TB screw" is not an idle adjustment, and using it as you did to set the idle with the IAC disconnected has undoubtedly created the problem.

You will need to re-establish the baseline throttle stop setting as described here. Disconnect the battery while you are resetting the stop screw to clear the KAM and force the PCM to relearn the IAC settings needed to properly control idle speed.

Oct 30, 2008 | 05:27 PM

#32

cisurfer

5th Gear Member

Joined: Aug 2006

Posts: 2,158

From: Central NJ

but why would it start doing this out of no where with my old iac? its doing the exact same thing with the new one...could it be the TPS or something else?

Oct 30, 2008 | 05:46 PM

#33

cliffyk

TECH SAVANT

Joined: Dec 2006

Posts: 10,937

From: Saint Augustine, FL

Quote:

Originally Posted by cisurfer

but why would it start doing this out of no where with my old iac? its doing the exact same thing with the new one<snip>

That would mean that the IAC you replaced was not broken ans you wasted your money buying a new one. The TPS has nothing to do with idle speed (and woiuld throw a DTC if it were stuck or damaged), however if that's what you suspect the problem might be go throw some more money down a rat hole.

Have you reset the throttle stop setting you messed up yet?

Oct 30, 2008 | 11:36 PM

#34

cisurfer

5th Gear Member

Joined: Aug 2006

Posts: 2,158

From: Central NJ

no i havent tried that, but if the old IAC wasnt broken, then why would it start doing this out of no where?

Oct 31, 2008 | 03:43 AM

#35

cliffyk

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Joined: Dec 2006

Posts: 10,937

From: Saint Augustine, FL

I don't know. If the throttle stop screw was grossly misadjusted perhaps it was bad and the new one cannot control the idle because too much air is getting past the throttle plate. It depends on how far off the stop screw setting is.

Get the stop screw adjusted properly and work it from there.

Oct 31, 2008 | 07:47 PM

#36

cisurfer

5th Gear Member

Joined: Aug 2006

Posts: 2,158

From: Central NJ

well i adjusted the screw properly and still the idle is going up the 2k and 3k i have no idea what this could be from

Oct 31, 2008 | 08:53 PM

#37

cliffyk

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Joined: Dec 2006

Posts: 10,937

From: Saint Augustine, FL

Did you disconnect the battery for 5-7 minutes while or after resetting the TB stop screw?

Are you certain you did the stop screw adjustment procedure correctly--you must first back the screw out unitl there is 0.010" clearance between the screw tip and the bellcrank tab--don't guess, use a feeler gauge--open and close the throttle a couple times to make sure the cable slack has been relieved, then recheck the clearance.

Nov 1, 2008 | 07:43 AM

#38

cisurfer

5th Gear Member

Joined: Aug 2006

Posts: 2,158

From: Central NJ

ok on your website it says do that then turn it one full turn...does that once the proper adjustment is set with the feeler gauge i turn the screw one full turn?

Nov 1, 2008 | 08:42 AM

#39

cliffyk

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Joined: Dec 2006

Posts: 10,937

From: Saint Augustine, FL

Quote:

Originally Posted by cisurfer

ok on your website it says do that then turn it one full turn...does that once the proper adjustment is set with the feeler gauge i turn the screw one full turn?

Step 2 states:

Quote:

Using a feeler gauge adjust the screw until there is 0.010" clearance between the screw and the throttle lever;

Then step 3 states:

Quote:

Turn the screw clockwise (tighten it) one full turn;

Since 3 comes after 2, then yes; you turn the stop screw in one full turn after setting the clearance to 0.010"...