tiburon

Want to set my base idle. My instruction say to disconnect battery for 20-30 min, then unplug the "idle motor".then continue on with procedure.
What /whereis the idle motor?, is this refering to the IAC? I dont want to unplug the wrong thing.

TwotoneVert

What model are we talking?

tiburon

87 GT.......

88 ASC Mclaren

I would think it talking of the TPS, what is the part your changing?

tiburon

Im not really changing a part, Im just trying to reset my base Idle and then set my TPS voltage accordingly. I have been having a hard time getting TPS voltage at .98without having the idle up too high (1000-1100)

86GreenMachine

Yep its your IAC motor.Unplug the clip when your setting your base idle.

Joel5.0

You don't have to set the TPS to .98 or .9999 vdc....that is a Myth.....as long as the TPS is within its operational no-failure-code generated window (= .5 - 1.19 vdc)...the computer will filter/rezero itself to the minimum it reads. Optimum range (to allow for temp and voltage variations) is .7 - 1.0 vdc...if it's within that range leave it as is, let the computer do its job. Here's the very short version.

Bring engine to op temp.
Disconnect IAC.
Adjust minimum idle to 650-670 rpms.
Turn engine off for 20+ seconds
Repeat setting wit IAC disconnected.
Turn engine off for 20+ seconds
Verify TPS closed throttle value is within the .7 - 1.0 vdc window.
Reconnect IAC
Turn engine on and let it idle

Every time the ignition is turned on, the ECM will set closed throttle value using the minimum reading + it continuously monitors for for changes, if a new minimum is read, it automatically uses that new minimum reading as the base TPS voltage.

tiburon

Thanks a lot, that explains the trouble I was having. It seems I could only get a steady idle at the right rpm when the TPS voltage was at about .87-.91 VDC. I'll set it up and leave it . Thanks again