another hanging idle question - stock TB

[venomous99]

my idle hangs around 1500 at times and stays there anywhere from 20-30 secs at times and eventually returns to normal idle.
the tps reading was .93V and ive adjusted it to .96V this morning but havent gone for a test drive to see if that fixed it.
ive read that as long as the voltage at no throttle stays is anywhere in the range .6 to 1V this is normal as the computer recalibrates the baseline/no throttle voltage.
so why is it that ppl try to target 0.96 to .98 at no throttle? does it really make a difference?
i had my throttle body off to get it polished while my motor was being rebuilt and since then the idle has been hanging. the tuner checked the idle settings via the tune and everything appears to be inline so i suspect the issue is something else. when i had the throttle body off only the tps was removed and the idle screw was not tinkered with.
anyone have some suggestions?

 

[moddedmystic]

You've gotta set your base idle(mechanical). Do a search on mod fords under hanging idle and you find the procedure to set your base idle :beer:

 

[venomous99]

here is what was posted in a thread on setting idle and apparently this is for foxes and not obd2 cars
Originally Posted by moddedmystic View Post
You need to set your base idle.
Here are the directions,

Fix for hanging idle
1) install TB and plenum
2) rotate the TPS CW(opposite throttle movement) then snug the screws
3) plug IAC in (DO NOT SCREW IT ON, LEAVE IT OFF)
4) duct tape over the IAC holes on the plenum
5) have someone start the car(DO NOT TOUCH THE GAS PEDLE) if it won't start, turn the butter fly stop screw in a bit, try to start again(repeat till running)
6) adjust the stop screw till you get the idle to 700-750RPM
7) let the car idle for 5-10 min's
8) turn car off
9) remove duct tape, install IAC
10) turn key to "on position" (do not start car)
11) set TPS to about .98V, tighten the TPS
12) start car(DO NOT TOUCH THE GAS !!!!!!!!)
13) just let the car idle, let the computer "LEARN" for 10min's
14) turn car off
15) done

This outlined proceedure is common for use on 87-95 vehicles. 96 thru current the ECM has a TPS self zeroing ability. Also base idle is set thru the tune as an idle setting, it isnt always 700-750.
Idle air tables need to be adjusted accordingly via integrator corrections and learned behavior. After the throttle stop screw is set correctly.

When we tune the idle on new TB that we suspect the idle screw might possibly be misadjusted we lock the IAC in the tune and set base idle to what is in the tune. Then the idle air tables are worked in accordance to the learned corrections.....the key is you want minimal corrections.

 

[moddedmystic]

Worked for me brother,give it a try :beer:

 

[venomous99]

moddedmystic, u also had the 1500 hanging idle and doing that procedure took care of it? other ppl have used this method successfully? i wish ford would've used some better screws on taht stupid tps. i think ill go to the hardware store and get one with a hex cap or something rather than screwing it in to mount.

 

[moddedmystic]

Its worked on a variety of different throttle bodies Ive had on my car. If you try it and idles better but you cant get the voltage right, just drill out the holes in the TPS a little(to get more swing on it). Hope that makes sense....

 

[venomous99]

so im trying to mess w/ this step by step so looks like the tps adjustment did nothing and i dont think the throttle is sticking as the tps is at closed condition when the idle hangs at 1500
[ame="http://www.youtube.com/watch?v=2p16vmBHSdo"]YouTube- 97 mustang hanging idle[/ame]

 

[04svtsnke]

bringing back an older thread, how do you start the car and it not mess someting up without the intake on or maf plugged in?

 

[greengt88]

vaccuum leak?