Trouble starting sometimes?

[vaden87]

Early 97 Disco

I drove my girlfriends disco tonite instead of mine and i noticed it has just recently had trouble starting. The first time you start it, the truck acts as if it will die just for 2 seconds and then it either dies or runs fine. OR It wont crank. Just sounds like its about to but never really does. When I get behind the wheel, it cranks fine without any doubt 90% of the time - it knows me cause I am the one that works on it.

What does the Stepper motor do?

Also, if it wont crank, i take the key out put it back in and it cranks with no acting - a real strong solid sound start like my rover.

Thanks for your help

Ryan

 

[Joey]

Idle air control (IAC)

Idle speed is controlled by a stepper motor which
consists of two coils. When energised in the correct
sequence the coils move a plunger which opens and
closes the throttle bypass controlling the quantity of
idle air. The stepper motor controls idle speed by
moving the plunger a set distance called a step. Fully
open is zero steps and fully closed 180 steps. Failure
of the stepper motor will result in low or high idle
speed, poor idle, engine stall or non start. The fault is
indicated by illumination of the malfunction indicator
light (MIL) on North American specification vehicles.