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4.9 idle problem by ozzman333
Started on: 05-27-2014 02:08 PM
Replies: 12 (280 views)
Last post by: ozzman333 on 06-03-2014 01:15 PM
ozzman333
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Report this Post05-27-2014 02:08 PM Click Here to See the Profile for ozzman333Send a Private Message to ozzman333Edit/Delete MessageReply w/QuoteDirect Link to This Post
I done a 4.9 swap with a 4 speed manual, when I start the car it idles ok,when I drive it idle stays high and when I come to stop light and push clutch in the idle stays high for a few seconds then idles down, it has only started doing this recently, didn't do this after I first did the swap.
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Mickey_Moose
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Report this Post05-27-2014 05:12 PM Click Here to See the Profile for Mickey_MooseClick Here to visit Mickey_Moose's HomePageClick Here to Email Mickey_MooseSend a Private Message to Mickey_MooseEdit/Delete MessageReply w/QuoteDirect Link to This Post
...normal...one of the things that bugged me with the 4.9 and with a manual.

Do a search for "4.9 sail on" and ways to minimize it.

found the link: http://www.fiero.nl/forum/A...050119-2-049097.html

[This message has been edited by Mickey_Moose (edited 05-27-2014).]

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arte444
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Report this Post05-28-2014 03:52 PM Click Here to See the Profile for arte444Click Here to Email arte444Send a Private Message to arte444Edit/Delete MessageReply w/QuoteDirect Link to This Post
Probably the ISC motor. Could try recalibration or just plain disconnect it. Have to blip the throttle on mine to keep it alive without ISC.
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ozzman333
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Report this Post05-29-2014 10:04 AM Click Here to See the Profile for ozzman333Send a Private Message to ozzman333Edit/Delete MessageReply w/QuoteDirect Link to This Post
IF I REPLACE THE ICS WITH A USED ONE THAT I KNOW WORKS FINE DO I HAVE TO RECALIBRATE IT WILL IT WORK PROPER AFTER I INSTALL IT
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SERGE144
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Report this Post05-29-2014 10:09 AM Click Here to See the Profile for SERGE144Click Here to Email SERGE144Send a Private Message to SERGE144Edit/Delete MessageReply w/QuoteDirect Link to This Post
If you turn the minimum idle down to 400 rpm and follow the idle learn procedure, it should improve.
Nothing worked for me until the idle adjustment.
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ozzman333
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Report this Post05-29-2014 10:52 AM Click Here to See the Profile for ozzman333Send a Private Message to ozzman333Edit/Delete MessageReply w/QuoteDirect Link to This Post
turn idle down to 400? I have a manual tranny
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olejoedad
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Report this Post05-29-2014 12:34 PM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
Turning the idle down to 400 causes the PCM to command a quicker idle down, it will idle around 650 rpm. Its just a calibration trick.
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ozzman333
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Report this Post05-29-2014 07:15 PM Click Here to See the Profile for ozzman333Send a Private Message to ozzman333Edit/Delete MessageReply w/QuoteDirect Link to This Post
i am going to do the idle learn tomorrow, but unplugged the ics just to see what would happen and when i did the car idled really high, everything a read on here about unplugging the ics says it makes it idle lower
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phonedawgz
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Report this Post05-29-2014 09:07 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
Unplugging the ISC freezes the idle speed adjustment wherever it was when you unplugged it.
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ozzman333
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Report this Post05-30-2014 02:47 PM Click Here to See the Profile for ozzman333Send a Private Message to ozzman333Edit/Delete MessageReply w/QuoteDirect Link to This Post
I am going to do the idle learn procedure this weekend,on the instructions posted by fieroseverywhere, the last step says to let the car idle in park and drive for two minutes each, what is the procedure for a manual tranny
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Mickey_Moose
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Report this Post05-30-2014 05:11 PM Click Here to See the Profile for Mickey_MooseClick Here to visit Mickey_Moose's HomePageClick Here to Email Mickey_MooseSend a Private Message to Mickey_MooseEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by ozzman333:

I am going to do the idle learn procedure this weekend,on the instructions posted by fieroseverywhere, the last step says to let the car idle in park and drive for two minutes each, what is the procedure for a manual tranny


There is no "procedure" for a manual tranny as the 4.9 never came with one - just follow what is posted in that thread using the lower idle value of 400 - just ignore the step with it in drive (although if you have AC run that at full tilt for this step) - put the car in neutral for the park step.

Doing this is not perfect by any means, but it is the best solution and the problem will still exist. Just not as bad - only way around it is to hack the ECM programming and change the code (which no one has figured out).

I suppose you can always retract the idle screw and leave the motor unplugged and then adjust the screw to the desired idle - not sure if this would cause any other 'issues' or not. Never heard of anyone doing that.
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Fieroking
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Report this Post05-31-2014 12:41 AM Click Here to See the Profile for FierokingClick Here to visit Fieroking's HomePageClick Here to Email FierokingSend a Private Message to FierokingEdit/Delete MessageReply w/QuoteDirect Link to This Post
I did the complete idle learn procedure on my 4.9 with a 5 speed manual adjusting both the IAC and the TPS per the procedure. My car ldles down just just like it should and idles at 750 rpm. The sail on adjustment is used to get rid of the high idle. Another issue with the 4.9 is the O2 sensor, the Bosch O2 sensor causes a high idle. I had to put a AC Delco O2 sensor to make my car run correctly.

Joe Sokol

------------------
85 SE Daily driver with a 3.4 DOHC OBD II
88 Formula/GT 4.9 Allante Intake (My Baby)
www.fieroking.com

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ozzman333
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Report this Post06-03-2014 01:15 PM Click Here to See the Profile for ozzman333Send a Private Message to ozzman333Edit/Delete MessageReply w/QuoteDirect Link to This Post
didn't get to my idle problem this weekend but hopefully this week. I had my chip redone and believe the idle was set to 800 rpm, when I do the idle relearn do I still set the minimal idle to 400 rpm
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