Bad2ndgen

I just got my Haltech and tried to search the forum on how many of you are using the idle speed motor. Just wanting to know if it's necessary to keep it for a good idle? I'm trying to simplify my engine compartment as much as possible and don't want to use anything that's not absolutely necessary.

Thanks in advance!

Styk33

If you are using A/C it is recommened that you keep it. Otherwise it is not needed for a steady idle.

Bad2ndgen

A/C= less HP's. Got rid of that a long time ago. Thanks dude!

jetenginedoctor

Hmm. . . . I can't help but bite on this one.

Please explain how A/C equals less HP????

BK

BMEP Fuel & Tuning

AnthonyNYC

iTrader: (3)

I really like it a lot. I used it in my car all the time. One for AC (which is gone now) but the other is in cold weather.

I had my car set to idle at 1100 if the coolant temps were below 170degF. After that it would drop to 800rpms and stay there. Kinda like stock.

I just found hitmans info that helped me in the past.

I will attach.

Anthony

AnthonyNYC

iTrader: (3)

Here ya go!

HITMAN’S GUIDE TO SETTING UP YOUR BAC.
Please note that this is a simple guide and some things may change
from one
car to the other. I am going to base this article on the Series
4/5 13BT
motor, which so many on the Haltech list have.


BAC , WHAT IS IT ?
First of all a description of what BAC idle control is and what it
does.
BAC stands for Bypass Air Control. It is a system where a passage
of air
around is setup around the throttle plate to allow the engine to
raise and
lower in rpm. This variation of rpm is usually controlled via a 2
or 3 wire
solenoid. This solenoid is pulsed at a particular frequency, which
varies
from solenoid to solenoid. It is the length of each of these
pulses that
determines how much air is allowed to go in. The larger the time
the more
the valve is head open and the more air goes in. The more air that
goes in
the higher the rpm. This is all controlled by the ECU.


HOW DO I SET IT UP WITH MY HALTECH E6K?
I will cover the 2-wire types here, but 3-wire BAC slave type
systems are
very similar. You should also not try and enable your BAC or fine
tune it
until your motor is completely tuned. Having tuning issues around
the idle
speed region will make it difficult to set up the BAC.

The 2-wire types are very easy to wire up. All you need is to
select a PWM
wire that you have free, and run this along with a 12V+ Grey/Red
wire to the
BAC valve and connect them. It should not matter which pin is
positive or
negative.
Now, if you go online with your Haltech, go to the PWM Output
Options page
by hitting CTRL-W.
Go down to the PWM output number that corresponds the the wire you
connected
to the BAC, and with the TAB key toggle through until you get the
BAC Valve
option. When you do, hit the ENTER key. This will lock it in as
the
desired output. It will then give you two options under BAC
Valve. One os
to Enable or Disable the feature, the other is the Period (or
frequency) at
which the solenoid will be pulsed. This value is usually found
through exper
imentation, or by simply asking someone who has done it before.
On the
13BT motor which I am using as an example, the I have found to work
well is
around 24ms. Others may find values that differ, so use whatever
works best.
Once Enabled the BAC output will start to function and now needs to
be
setup. Do not Enable the BAC at this point, we have other areas to
cover
first.

Here is where it gets a little confusing. If you go to the Output
Options
page by hitting CTRL-O, you will see the Idle Speed Control
feature. In
order to use BAC this feature needs to be left DISABLED. The
settings here
will still work but only if left in Disabled Mode. If Enabled the
E6K will
think you are trying to run a 4-wire stepper motor for idle
control, and not
a BAC valve.

What needs to be done now is to set the throttle stop. What we
generally
need to do is to setup the throttle stop to maintain idle speed
around 50 to
150rpm below the Target Idle Speed we wish to obtain. Once this is
done the
throttle stop can be locked and the TPS will need to be
recalibrated. If the
TPS reads anything other than 0% or 0% Fault then the BAC function
will not
work.

The next step is to go an Enable the BAC Valve PWM Output. Hit
CTRL-W and
go down to BAC Valve and change it to Enable. Once done go to the
Output
Options page and you can start adjusting the Idle Speed Control
settings.
Remember to leave this feature as DISABLED so that the settings
will effect
the BAC and not try to use the 4-wire stepper motor.


IDLE SPEED CONTROL SETTINGS
This is a short summary of what the Idle Speed Control settings
do. This is
based on Firmware 14 and software 6.34 which is the current release
at the
time. Some settings may differ if you are using another software
and
firmware version.

Target Idle Speed - This one is pretty obvious. This is the idle
speed
that you wish the engine to be at under normal conditions.

Cold Idle-Up RPM - This is the amount of RPM added to the Target
Idle Speed
when the coolant temperature is below the amount set under Cold
Temp. Limit.

Start RPM - The amount of RPM added to the Target Idle Speed for
the first
20 seconds after starting the motor. It is done to help stabilise
things.

Number of Steps - This sets the increments in which the BAC is
controlled.
It is another word for sensitivity. I usually start around 100 and
use trial
and error from there.

Cold Temp. Limit - The value under which the engine is considered
to be
cold.

Cold Min Position - The minimum duty the solenoid will be pulsed
at while
the engine coolant temp is below the figure set in the Cold Temp.
Limit.
More on this later.

Hot Min Position - The minimum duty the solenoid will be pulsed
at while
the engine is at operating temperature. More on this later.

Cold Opening Position - The duty at which the solenoid is run
during
cranking while the engine is below the Cold Temp Limit. It is to be
set
higher than the Cold Min Position and acts the same way as opening
the
throttle during cranking.

Hot Opening Position - The duty at which the solenoid is run during
cranking while the engine is at operating temp. It should be set
higher than
the Hot Min Position.


HOW TO USE THE IDLE CONTROL SETINGS ON A REAL CAR
After we have the car idling on the throttle stop and we have
Enabled the
BAC, this is the process to go through to obtain the best idle speed
control. Setup should be done initially with the engine at
operating temp,
then later go through and do the cold engine settings.

First we need to set the Target idle speed. Easy enough to do. If
we want
900rpm idle then set it to 900.
Next to setup is the Hot Min Position. This is rather simple to
do. Set a
target idle speed that is really low. Say 500rpm. This will cause
the BAC
to almost completely turn off and rely on the throttle stop to keep
the car
idling. If everything is working correctly then you should have the
engine
idling on around 800rpm if the throttle stop is correctly setup.
What we do
now is to increase the Hot Min Position until the revs start to
rise. When
we can get an idle just below 900rpm (the target idle speed) then
the Hot
Min Position is set. We can now change the Target Idle Speed back
to 900rpm.
Next on the list is to do the Hot Opening Position. To do this you
set a
value a little higher than the Hot Min Position. I usually add
around 20%
to it. Now switch off the engine and try to restart. If the engine
revs are
low and build up try adding more to the Hot Opening Position. Is
the revs
are too high then lower the value.
The Start RPM can now be set. This just keeps the rpm a little
higher for
the first 20 seconds. A value around 100 or 200 is good enough for
most
applications.

You will have to let the engine sit overnight to be able to do the
Cold
settings. These are done the same way as the Hot settings and will
be
almost always a higher value. Putting in values around 20% higher
than the
Hot values is a good starting point and adjust from there.
First up is the Cold Idle-Up RPM. This can be set so that the RPM
is a
little higher to warm the car up faster, and is set to the users
preference.
A good starting point is 200rpm higher but a higher value is
sometimes
better.
The Cold Min Position can now be set. Try increasing this value
until the
rpm rises above the Cold Idle-Up amount. ie if we have a Target
Idle Speed
of 900 and a Cold Idle-Up of 200 then while the engine is cold it
will idle
at 1100rpm. If we increase the Cold Min Position until the rpm
just starts
to go higher than 1100rpm, then drop it down a little we will have
it set to
its optimum.
The Cold Opening Position can now be set in the same way the Hot
Opening
position was set. this will be higher in value than the Cold Min
Position.


That just about does it. If followed step by step all should work
well. If
you find the BAC stops working, try checking that the TPS still
reads 0% at
idle. If it fluctuates between 0% and 1% then contact me and I
will show
you how to get around this.