Re: Continuous Idle

["Robert Rooney" <DMCVegas@xxxx>]

Your idle speed regulator and motor are both working fine. The idle 
speed regulator on the DeLorean is not spring loaded. The rotary 
slide valve rotates clockwise/counter clockwise, but it DOES NOT spin 
360º. 

How the airflow is controlled:

Attached to the end of the shaft inside of the motor is a piece of 
metal that blocks the airflow going into the engine. As the motor 
turns it either blocks to opening to decrease the amount of air going 
into the engine, or slides out of the way to allow more air to enter. 

How the motor works:

Think of it like this: You have 2 electro magnets, and between 
them is a steel ball. If you want the ball to roll to the left, you 
would obviously give power to the left magnet. And when the ball has 
reached to point you want it to be at, you simply shut the magnet off 
and vice versa. The idle speed regulator works much in the same way. 
When idle is increased the ECU grounds the connection on one side to 
force the motor to rotate counterclockwise to open up airflow. Once 
the idle has reached it's desired RPM's, the ECU kills power to the 
magnet and again vice versa.

How the entire idle speed system works:

When the engine is on, power is applied to the idle speed ECU. 
When the gas pedal is at rest the throttle plates fully close (to 
give total control over to the ECU), and a microswitch is tripped. 
When this switch is tripped, it grounds a wire connection telling the 
ECU to activate. On the left side of the ignition coil is a 
white/slate wire. This wire feeds a signal back to the ECU to report 
the RPM's of the engine. From this signal the ECU determines
weather 
or not to either increase or decrease the amount of air going into 
the engine in an effort to match the RPM's of the engine to the 
predetermined amount programmed into the ECU. The purpose of this is 
to keep the engine from dying if a load is placed on it while idling 
(i.e. air conditioning is turned on), and to keep the car fuel 
efficient and environmentally friendly (slower the engine runs, the 
less gas it will use, and the less emissions it will create).
The only other part of the ECU is a thermal probe in the "Y" pipe 
on top of the engine. When the water is below a certain temp (50 some 
odd degrees or so), the ECU switches over to a cold temp RPM setting. 
Functions of the ECU are not disabled nor do they change in any way, 
the idle speed setting is only temporarily increased to slightly 
speed up the car's idle (a cold engine has more friction, plus it 
somewhat helps to warm the catalytic converter up quicker to reduce 
emissions). Even though the idle speed ECU shares the connection from 
the igntion coil with the ignition ECU for example, it works 
independantly of all other ECU's and their components.

To test that your idle control system is working properly, try 
this: When your car is idling @ a normal temp, unplug the motor, then 
flip the A/C on.

-Robert
vin 6585 (The DeLorean from hell.)



--- In dmcnews@xxxxxxxxxxx, Delorean17@xxxx wrote:
<SNIP>
when I remove the connector to the idle 
> speed motor nothing happens at all and it continues to idle fine.  
I thought 
> the car would die when the idle speed motor stopped.
<SNIP>