Yey! Some of you may know that I always posted about the (FC) BAC valve, and how to get it to work (E6k). Well after trying many many things, I could never get it 100%. I called it quits and bought this:

I also bought the GM type idle air control valve also in the picture. Figuring out the wiring was a bit tricky, but this thing works fantastically. I had my car fully warmed up, and backed off my throttle stop screw, letting the car idle naturally at 900-1000 rpm. Now if I were to put on the lights, heater, press the brake... the idle would drop to around 700-800 and was also lumpy. No more! With this valve operating, it stays at 1000RPM solid, regardless of the lights, heater, brakes whatever. Doesn't even pause and take time to kick in, it all works immediately. It's like a brand new car.

Now I just have to wait for the car to cool down and do the cold settings

 

Congrats!

 

I wish I found this thing sooner, I never would have bothered with the dopey BAC. After all my trials and tribulations, I came to the conclusion that the BAC is too inconsistent, especially with ported engines and different than stock timing amongst things. I got it to function OK with cold temperatures, but once the car warmed up it never worked right.

 

no voltage compensation settings in that software?

 

Only for injectors.

 

nice! how much the setup run and was it hard to install?

 

It's pricier than a (used) BAC valve...
The piece from risingrpm is 60 something. The valve is 34 from summit.
It was tricky to setup though. I tried to do it inside the car to see how it functioned, but it kept opening all the way. I kept playing around, but couldn't figure it out. Finally I just attached it all to the manifold, started the car and it had a big open vacuum leak as you'd imagine. Car was idling around 1700, but after playing with settings, it responded well and precisely. I figured it all out in a few minutes. Still have to make some intake tubing and do the cold settings.

 

any clue which GM IAC it is? so i can c if i can get from junkyard

 

I used this:
http://www.summitracing.com/parts/SMP-TTRAC1T/
and this harness
http://www.summitracing.com/parts/PCO-5612PT/

Anything that screws in should work.

 

You mind posting your settings?

 

Haven't done cold yet...

Steps: 150
Hot Minimum: 9
Hot Opening: 50 (may have to lower this)

This only applies to my engine! The hitman instructions work. Just start low and keep increasing the numbers till idle increases for the minimum position. The opening position is a little tougher. Rev the engine, and see how the engine behaves when coming down. If it hangs, or worse, drops then starts surging, your number is too high. You have to play with it till the point you can see that it drops, holds for a fraction of a second, then falls off again.

 

You come up with some pretty innovative ideas! <thinking of the OMP roller cam post>

 

^I saw some guy in the 2nd gen section CUT off the OMP lever on the throttle body because "he was going to premix anyway". Made me sad...

 

How do these valves have to be managed? I have an Rtek 2.1 and I'm wondering if I could make this work decent...

 

no

 

Use the stock BAC valve!

 

The stock BAC valve is a fixed frequency, pulsewidth modulated linear solenoid valve. That means it's a plunger that just pulses on and off based on a duty cycle command from the ECU, which is something the RTEK can't directly adjust.

The valve in this thread is a stepper-motor type. Magnets move the valve to discrete positions or "steps." They are generally higher flowing valves than duty-type valves. A stepper-type valve is controlled differently than a PWM valve; it's not a "drop in" solution for a stock ECU or Rtek.

 

I am not familiar with the RTEK other than it's the "stock" ECU, but programmable. I figured it would still run the stock BAC valve.

In other news I have lost the valve and/or computer and no longer have my idle control I have finally given up.

 

what did you do to it?

 

One and/or both crapped out. I'm done with it all!

 

I figured it wouldn't be drop in, that's why I asked how it's controlled. If all it needs is a DC voltage input I'd be happier using a variable resistor in the dash to control my idle than my finicky BAC, not to mention my connector pigtail is broken all to ****. I also would prefer an idle from 900-1250RPM, something I haven't had much luck getting the Rtek to accept.

 

Unless your motor is heavily ported, the Rtek (stock ecu) and a properly functioning (not broken or clogged) should have no problem with idle. If it is ported, then a standalone ecu is your best bet. A stepper motor ECU is not "simple" in its operation.