Well, if the little screw isn't touching at all then your butterfly isn't open at all and your car technically shouldn't idle at all (because it's not getting any air w/ the butterfly closed - the IAB/IAC doesn't work at idle) unless you have a major vacuum leak, have holes drilled in your butterfly, or you have one of the idle adjuster plates w/ the two little screws (basically a controlled vacuum leak).jstang209 said:
Did you readjust your TPS after backing your idle screw out? You MUST do this...if you don't, that maybe could cause your problem if were reading too far out of range for idle. But, it really shouldn't idle w/ the butterfly closed unless you have one of the 3 characteristics listed above.
One way to check for vacuum leaks is to start the car and spray starting fluid/ether around all your gasket surfaces to see if the idle increases - if it does, there's your vacuum leak.
What is your timing set at? Did you use a Timing Light to set timing? What does the car idle at? What have you recently done to the car? Do you have any "check engine" codes?
Just for fun, you might try cleaning your throttle body and IAB/IAC just for fun. Here's a link to that: http://www.muscularmustangs.com/iac.html
And yeah...the timing probably wouldn't affect your idle that much as long as it's between 10-14 like mentioned above.
And to reiterate, I would NOT use timing as a means to adjust the idle. The idle is computer controlled (though we play with it, it still tries to go back to its stockish ~670 RPM).
The link that James provided is a nice way to start over and see if it helps. WHen doing something like that, I like to write down every adjustment made, etc (I use a dab of paint on screw heads as a reference point) so you could always get back to how you have it now.
Good luck.
The link that James provided is a nice way to start over and see if it helps. WHen doing something like that, I like to write down every adjustment made, etc (I use a dab of paint on screw heads as a reference point) so you could always get back to how you have it now.
Good luck.
That's not how to go about setting the idle.
To set the idle, you need to disconnect the IAC by unplugging it and then set the idle using the set screw.
Once you set the idle using the screw WITH THE IAC DISCONNECTED, then you need to reset the computer by unhooking the battery for 15 mins. Hook the IAC back up, along with the batery and restart the car. Let it idle two mins and then turn EVERY power accessory on and the A/C if it works (or the heat) and let it run 2 more mins. Then shut everything off and let it run 2 more and then shut the engine off.
Start the engine and pull the SPOUT out, set timing to 10-14 degrees and call it a day.
You might want to check the TPS voltage at idle as well. Anything over 0.96 volts will trigger off-idle fuel curves.
The reason you cannot set iduel by turning the screw without resetting the comp is because the car will try to compensate for you closing the scre by raising the idle by opening the IAC. You need to eliminate it's ability by disconnecting the IAC when you set idle. After that you reset the comp so it "forgets" it's old idle strategy and relearns the new one
To set the idle, you need to disconnect the IAC by unplugging it and then set the idle using the set screw.
Once you set the idle using the screw WITH THE IAC DISCONNECTED, then you need to reset the computer by unhooking the battery for 15 mins. Hook the IAC back up, along with the batery and restart the car. Let it idle two mins and then turn EVERY power accessory on and the A/C if it works (or the heat) and let it run 2 more mins. Then shut everything off and let it run 2 more and then shut the engine off.
Start the engine and pull the SPOUT out, set timing to 10-14 degrees and call it a day.
You might want to check the TPS voltage at idle as well. Anything over 0.96 volts will trigger off-idle fuel curves.
The reason you cannot set iduel by turning the screw without resetting the comp is because the car will try to compensate for you closing the scre by raising the idle by opening the IAC. You need to eliminate it's ability by disconnecting the IAC when you set idle. After that you reset the comp so it "forgets" it's old idle strategy and relearns the new one
What have you recently done to the car? Do you have any "check engine" codes? If you have access to a vacuum gauge, it would be handy to know what vacuum you're pulling - also your cam specs too.
If you did everything Mustang5L5 said (he wasn't trying to be rude, he was trying to make sure you covered everything), then it really sounds to me like you probably have a vacuum leak.
I would seriously pull codes and see if you have any out of range sensors or anything of that nature.
If you did everything Mustang5L5 said (he wasn't trying to be rude, he was trying to make sure you covered everything), then it really sounds to me like you probably have a vacuum leak.
I would seriously pull codes and see if you have any out of range sensors or anything of that nature.
Hey everybody-
I really want to help this guy but he has 3 or 4 threads going about the same problem- each thread with something a little different. He say's it won't idle, its loud, sounds like a marble is bouncing around in the motor.......we need to consolidate problems!
I hope I have the right guy......I think so.
I really want to help this guy but he has 3 or 4 threads going about the same problem- each thread with something a little different. He say's it won't idle, its loud, sounds like a marble is bouncing around in the motor.......we need to consolidate problems!
I hope I have the right guy......I think so.