dubulup

So how is everyone’s ISC or BAC doing? Mine is okay…when hot it’s great, when cold not so great…holds idle fine, a tad noisy (10ms in PWM set-up), and can’t get it to cooperate with start rpm or cold rpm.

Some background info for those wondering or those who don’t know.

The idle speed controller is a controllable valve that opens and closes an air passage around the throttle plates to get a smooth and controllable idle. I say controllable because, there is a start rpm setting and a cold rpm setting and an idle setting. Haltech sets this up in a stepper motor configuration…if it is indeed a stepper motor, I do not know at this point in time, so ReTed or somebody please check in. (stepper motor – 4 wires, stock ISC – 2 wire, 12V and a pulse GND)

The idle setting is what it is…I want my car to idle at 800 rpms, so I set the idle setting as such. (car idles 820-880)

The cold rpm setting is a bump in rpms to accelerate warm up, not like the AWS cruel and unusual punishment type…up to 500 rpms. Mine is set at 500, so when cold my engine should idle at 1300 rpms. It doesn’t. At least not without a little coaching help from my right foot.

Start rpm is a setting that only lasts for 20 seconds. Every time you start the car, this setting bumps the idle up. I had mine set for 1000 (MAX), so when cold my car should start and immediately idle to 2300rpms for 20s, then drop to 1300rpms until the engine coolant temp reaches 135 then drop to 800. Hot start, Idle up to 1800 and 20s later drop to 800.

This does not happen…cold starts my idle sticks at 740rpms. Just to not complicate things, I now have start rpm set to 0.

This is my interpretation, so if I’m thinking of this the wrong way, please step in and open my eyes.

Now for the stepper motor set-up:
# of steps (0-150), a stepper motor has steps along a path (most I’ve seen are little belt driver types)…i.e. A signal sent for back or forward and # of steps. Example: forward 15: given location add 15 steps (how this is accomplished with only one pulsed wire, I don’t know) Anyway, you can set the # of steps. Way I look at this is…IF there are 150 total steps and you set # of steps to 100, 100 is the “new” maximum open position, where step location 150 will let the most air around the throttle plates. This option seems to have little effect on my outcome. Mine is set at 25. (Haltech recommends starting with 100)

Cold min and cold opening positions (%): Everyone has they’re own way of viewing this or explaining this, I’m unclear so I’ll give my explanation. Cold min position is the lowest position along the controllers “path”…this is the minimum amount of air that will be allowed around the TB. Hot min is the same. So, my cold min is around 40% (Haltech recommends starting around 80%-90%)
Cold opening position…this is the position where the controller will wait to take control of the motor. Can it be lower than the min position? Or is the opening position a % of the cold min %? Mine is set to 22. Haltech recommends starting around 40%. Hot min is the same.

IF it can be lower and my interpretation is correct, my ISC will wait at 22% open, then once under control it will oscillate between 40% open and the max open until a solid idle is achieved using 25 steps. BAAAAAAAAA…BAAA…BAAAAAAAAAAAAAAA…BAAAA…BAAAA…etc This is what I hear, when cold right at a solid 820rpm, no hunting what so ever. Once warm the noise goes away. Hot settings are 5% opening and 3% min.

When cold if I hold the rpm up a tad, the controller will get the hang of it and hold it right at 1320.

Any thoughts or interpretations? Why can’t my start rpms be added on top of the other settings? Is it because this is not a real stepper motor? How come my cold settings seem to not idle +500 of the idle setting? How does the damn thing work with only one pulsed signal? I know the settings are working some what (because I will get nasty hunting and different noise pulses), but what are they really doing?

Let’s discuss…

Again once the engine is up to 135 or so, its rock solid, and have no complaints.

dubulup

I will be trying new things...as I only get a few chances to tweak the cold settings before the engine gets to temp.

Other factors I did not mention...the idle screw on the front of the TB (the one that opens the bottom butterfly to let a constant air flow in) and the idle screw on the bottom of the TB, I'm not sure what this one does...I'll definitely look into that. It might change the characteristics of the air path the ISC uses

Also this is on an FD. But I'd still like to hear from anyone that reads this. So, If I see 6 views and no responses...I won't be too happy

at least tickle my fancy and look at your settings and report back, with noises and behavior...there has to be running rotaries with Haltechs, so lets hear it. what'chu got?

Sesshoumaru

iTrader: (1)

the isc is not a stepping motor otherwise it would have a different name

it's just like the bac in that it uses square waves to to determine duty cycle.

The fsm says duty cylce at idle should be 60-80 i believe.

Adjusting the tb screw will be able to change those.

It seems like it might be pretty high duty cycles that is causing your trouble.

MrRx

iTrader: (1)

Im still working out my issue with the isc, I blocked off the bac, so far the isc works great after the cars hot, but when its cold it needs help for a bit

Sesshoumaru

iTrader: (1)

you can't have blocked off your bac and have you isc working

do you mean aws instead of bac?

i'm not sure if the bac or isc can provide enough air for the cold starts. That was the main reason for the aws and the thermo wax

r71

iTrader: (3)

that's a good point.

dubulup

so what are people with Haltech's doing for cold starts? sitting in the car with their foot on the gas? I doubt it.

I really wanted to see some people's settings, and yes every car is different...but not one person has any help for cold starts? I know they aren't using the AWS...

anyone have some insight they want to contribute?

Sesshoumaru

iTrader: (1)

post start map?

sorry for bothering you

dubulup

you're not bothering me...you made a good point about the ISC not be able to really idle up. That makes sense...and that was me, posting on r71, opps.

so if the ISC can't get enough air around the throttle plates, how is everyone warming up their cars???

so I richen the post start map...how does it get air into the motor?

crispeed

I've been using the 4-wire GM idle motor with great results. Never skips a beat and rock solid idle during cold start up, A/C use etc. I've always use the same settings and get just about the same results form car to car. The factory BAC valves require inconsistent settings form vechicle to vechicle to operate properly. I'm not saying they don't work with the Haltech because I've done them and they work but I prefer the GM idle motor.
The E6X do offer a lot more options over the previous E6K's for BAC control. I've not used the E6X to control the BAC as of yet so I cannot comment on the results.

jacobcartmill

iTrader: (6)

i'm wondering about this too. i am using my stock BAC as a PWM trying to get it to help with my cold idle, but i just cant figure it out. the car will idle on its own when i start it cold (40 degree mornings) but its around 500 rpms and its a little rough, i was gonna try to use the BAC as a PWM to "control" the idle but it doesnt seem to help no matter what i set the milliseconds to... anyone else have any input on this?

YearsOfDecay

I use my BAC as a high idle motor, getting the car to 2k until it reaches about 145 degrees. However.. I am beginning to suspect the BAC as leaking under boost... no, actually i'm quite sure of it cause I ran a tube from it into the cockpit and it blew into my face when I hit boost.... therefore... come spring.. its going and a blockoff valve is going in its place.

It also sucks air in at idle and while driving, making this ongodly whistling and wheezing noise when you are just cruising at part throttle.. And under boost, it sounds like a leak in a high pressure steam line....


Its going to be a cold weather only item from now on!!!

dubulup

Care to share cold settings?

GUITARJUNKIE28

if you think that's hard, try getting it right on a bridgeport... YIKES!

out of curiosity, if you unplug the bac, will your car still idle? most manufacturers suggest setting the minimum air rate (throttle stop) at around 600 rpm-but i take this as right about the lowest idle you can have without the motor stalling out. if you set the throttle stop there and use that as a base, you might have a little better luck.

dubulup

when warm it idles fine, so it's not stressing to hold an idle...haven't tried when cold.

does the # of steps really effect anything...it doesn't seem to change much when I change the #. Anyone have comments on that?

Maxthe7man

set the number of steps to 40, set the ms to 36, set the cold idle up to 400, start rpm 400
set your idle speed where your engine is happy, I run a half bridgeport, my idle speed is 1200 rpm, my cold opening position is 75%, my min cold 30, hot min is 15 hot opening is 30 IIRC...The factory bac works fine with the haltech, if its not working either you bac is bad or you have other problems...I have used these settings with S4, s5 and now S6 with no problems... I don't even have to be in the car to start it, last night I reached through the window when it was cold and started it, it sat around 1600 till 140 then idled down, thats on a fresh motor with not more than 40 minutes run time and 1600cc injectors in the primaries... It should be cake walk on a stock or streetported motor with smaller primaries..
As Crispeed said, though some settings will change car to car, I have found each motor has its own intake resonance depending on how its ported, you will get better bac valve control and idle, if you match the bac resonance to the intake resonace, do that by adjusting the MS in the PWM output page..

dubulup

Thanks for sharing!

your settings seem like they would be a bit noisey? Are they?

Maxthe7man

With the S4 and S5 the bac was pretty loud as it just had a small filter on the inlet, however if you plumb it back into the intake tract like a s6, its pretty quiet, I really have to listen for the bac valve now....Max

dubulup

adjusting it until you don't hear it anymore?