2001 DIES WHEN COASTING TO A STOP AND MODERATE TO HARD ON THE BRAKES
10-19-2011, 05:25 AM
#11
1st Gear Member
Thread Starter
Join Date: Sep 2011
Location: tx
Posts: 63
It's not a question of "not supposed to use the set screw to increase idle" but rather that it will not change the idle speed for any but a short time. The PCM controls the idle speed to whatever is set in the tune by altering the duty cycle of the signal applied to the IAC. Adjusting the throttle stop screw only affect the idle until the PCM learns the new idle air trims--after that all adjusting it does is screw up (no pun intended) the IAC operating range. It is possible to use the stop screw to open (or close) the throttle plate to the point that that IAC can no longer control the idle at all--this or a failed IAC will cause the stalling problems you described.
The throttle stop screw needs to be adjusted as described here, otherwise the IAC will not be able to properly control the idle.
Back to your original problem it sounds as though you need a new IAC. Ford makes it clear in the shop manual that it cannot be cleaned, and those who have done so have generally found it to be temporary fix at best.
The throttle stop screw needs to be adjusted as described here, otherwise the IAC will not be able to properly control the idle.
Back to your original problem it sounds as though you need a new IAC. Ford makes it clear in the shop manual that it cannot be cleaned, and those who have done so have generally found it to be temporary fix at best.
i already turned it back last night because at start up the car would make a temporary strange sucking sound (somewheat loud) under the hood until i blipped the throttle and then it would go away, I figured it was related to the IAC cleaning and/or dicking with the stop screw. I put the stop screw back where it was (there is a dam of blue paint on the top of if to show where it is supposed to be) should I reset the computer or will it re learn on its own?
10-19-2011, 10:37 AM
#12
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
thanks Cliffy,
i already turned it back last night because at start up the car would make a temporary strange sucking sound (somewheat loud) under the hood until i blipped the throttle and then it would go away, I figured it was related to the IAC cleaning and/or dicking with the stop screw. I put the stop screw back where it was (there is a dam of blue paint on the top of if to show where it is supposed to be) should I reset the computer or will it re learn on its own?
i already turned it back last night because at start up the car would make a temporary strange sucking sound (somewheat loud) under the hood until i blipped the throttle and then it would go away, I figured it was related to the IAC cleaning and/or dicking with the stop screw. I put the stop screw back where it was (there is a dam of blue paint on the top of if to show where it is supposed to be) should I reset the computer or will it re learn on its own?
It will relearn MUCH faster if you disconnect the battery for 5-7 minutes to reset the KAM...
10-19-2011, 07:48 PM
#13
1st Gear Member
Thread Starter
Join Date: Sep 2011
Location: tx
Posts: 63
10-19-2011, 09:47 PM
#14
1st Gear Member
Join Date: May 2006
Location: Michigan
Posts: 69
Are you sure you turned the set screw back to exactly where it was? Tighten all the clamps etc? How's your serpentine belt - or doesn't the squeal sound like that?
I had a similar problem to yours on my 01 GT. Mostly it was the failure to idle at start (or even failure to start without using the gas); but more than once it stalled at a light and many more times tried. Mine is an automatic, so coasting and stopping I still have the transmission engaged which makes a difference.
IAC cleaning and all was good. I didn't replace mine - just cleaned it and a quick job at that. I have since put another 20k on it and it is starting to act up again. It's at least the place to start. I wouldn't run out and put a new one on personally - try running your cleaned on for now.
I had a similar problem to yours on my 01 GT. Mostly it was the failure to idle at start (or even failure to start without using the gas); but more than once it stalled at a light and many more times tried. Mine is an automatic, so coasting and stopping I still have the transmission engaged which makes a difference.
IAC cleaning and all was good. I didn't replace mine - just cleaned it and a quick job at that. I have since put another 20k on it and it is starting to act up again. It's at least the place to start. I wouldn't run out and put a new one on personally - try running your cleaned on for now.
10-20-2011, 07:33 AM
#15
1st Gear Member
Thread Starter
Join Date: Sep 2011
Location: tx
Posts: 63
Are you sure you turned the set screw back to exactly where it was? Tighten all the clamps etc? How's your serpentine belt - or doesn't the squeal sound like that?
I had a similar problem to yours on my 01 GT. Mostly it was the failure to idle at start (or even failure to start without using the gas); but more than once it stalled at a light and many more times tried. Mine is an automatic, so coasting and stopping I still have the transmission engaged which makes a difference.
IAC cleaning and all was good. I didn't replace mine - just cleaned it and a quick job at that. I have since put another 20k on it and it is starting to act up again. It's at least the place to start. I wouldn't run out and put a new one on personally - try running your cleaned on for now.
I had a similar problem to yours on my 01 GT. Mostly it was the failure to idle at start (or even failure to start without using the gas); but more than once it stalled at a light and many more times tried. Mine is an automatic, so coasting and stopping I still have the transmission engaged which makes a difference.
IAC cleaning and all was good. I didn't replace mine - just cleaned it and a quick job at that. I have since put another 20k on it and it is starting to act up again. It's at least the place to start. I wouldn't run out and put a new one on personally - try running your cleaned on for now.
10-21-2011, 10:17 PM
#17
1st Gear Member
Join Date: May 2006
Location: Michigan
Posts: 69
Did you make any progress on fixing the issues? Just curious.
10-22-2011, 09:12 AM
#19
1st Gear Member
Thread Starter
Join Date: Sep 2011
Location: tx
Posts: 63
I set it back to where it was by eye and then reset the ECU by unplugging the battery. I replaced the IAC and it fixed the problem(s) - no squeal and no idle problem...hooray!
10-26-2011, 01:09 PM
#20
1st Gear Member
Thread Starter
Join Date: Sep 2011
Location: tx
Posts: 63
put new IAC in last week, everything has been good unitl this a.m. - hard on the brakes and motor died, could this be battery or alternator related - put voltmeter on batt when stiing - 12.5v - does the computer still need time to learn the mapping when the car is braking hard?