Tb Coolant Hose
02-28-2003, 02:55 PM
#21
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the BACV deals with more than just idle when AC is on, the BACV tries to maintain the idle in general, it's not directly associated to AC.
If you turn on a blower motor, or headlights, or defroster, or roll up / down a window (power windows) the idle will fluxuate due to the varying load applied via the alternator.
The BACV is the ECU's way of counteracting the varying load by fine tuning the amount of air getting to the engine. Without the BACV your
idle will dip when the load varies at idle, and possibly even die.
You can easily keep your BACV, even with an aftermarket ECU like the haltech E6K. It has a target RPM, and uses the BACV to keep it at that target.
If you turn on a blower motor, or headlights, or defroster, or roll up / down a window (power windows) the idle will fluxuate due to the varying load applied via the alternator.
The BACV is the ECU's way of counteracting the varying load by fine tuning the amount of air getting to the engine. Without the BACV your
idle will dip when the load varies at idle, and possibly even die.
You can easily keep your BACV, even with an aftermarket ECU like the haltech E6K. It has a target RPM, and uses the BACV to keep it at that target.
this is why I'm keeping mine
02-28-2003, 03:23 PM
#22
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Originally Posted by Racer X' date='Feb 28 2003, 08:18 PM
After I do the TB mod to mine to my engine I'm garbaging that BACV.No need for it after that.Just makes it easier to work on and one less thing that could go wrong.Look at how many rotaries never had it?Theres a reason for that. 
02-28-2003, 03:45 PM
#23
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Originally Posted by pengaru' date='Feb 28 2003, 04:23 PM
most fuel injected vehicles have a IAC (idle air control) motor, on the FC the BACV is the IAC equivalent. It's not a big deal, it doesnt need coolant, and it doesnt make things much messier. You'll probably wish you had it after you do it unless you don't mind your idle wandering around when the alternator places varying loads onthe motor (and possibly dying unless you set your idle high, which is annoying also)
02-28-2003, 05:25 PM
#24
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I have an '89T2. I don't have it anymore. My car idles at 800rpm. It idles very smoothly. It doesn't stall, die, or do anyting odd when it is cold or up to temperature. I'm not sure what the fuss is all about.
02-28-2003, 05:28 PM
#25
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Originally Posted by Jerk_Racer' date='Feb 28 2003, 06:25 PM
I have an '89T2. I don't have it anymore. My car idles at 800rpm. It idles very smoothly. It doesn't stall, die, or do anyting odd when it is cold or up to temperature. I'm not sure what the fuss is all about.
02-28-2003, 05:40 PM
#26
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Originally Posted by Jerk_Racer' date='Feb 28 2003, 11:25 PM
I have an '89T2. I don't have it anymore. My car idles at 800rpm. It idles very smoothly. It doesn't stall, die, or do anyting odd when it is cold or up to temperature. I'm not sure what the fuss is all about.
hell just hitting the brakes at idle will effect the idle because of the vacuum in the brake booster.
technically speaking... the idle will not be constant without any sort of idle air control, the load is not constant.
02-28-2003, 06:28 PM
#28
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In my previous post prior to that one I mentioned that I just looped the coolant hose that goes into that stuff into the back of the engine where it was going into originally.
I took all of that junk off as I did the throttle body mod. I followed RETed's writeup on his website, fc3s-pro. When I was done it ran like crap. Everything seemed cool with all of the vacuum connections so I broke out the trusty multi-meter (never leave home without one if you drive a FC) and reset the TPS. After that is was very nice.
I took all of that junk off as I did the throttle body mod. I followed RETed's writeup on his website, fc3s-pro. When I was done it ran like crap. Everything seemed cool with all of the vacuum connections so I broke out the trusty multi-meter (never leave home without one if you drive a FC) and reset the TPS. After that is was very nice.
02-28-2003, 06:41 PM
#29
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Originally Posted by Jerk_Racer' date='Mar 1 2003, 12:28 AM
In my previous post prior to that one I mentioned that I just looped the coolant hose that goes into that stuff into the back of the engine where it was going into originally.
I took all of that junk off as I did the throttle body mod. I followed RETed's writeup on his website, fc3s-pro. When I was done it ran like crap. Everything seemed cool with all of the vacuum connections so I broke out the trusty multi-meter (never leave home without one if you drive a FC) and reset the TPS. After that is was very nice.
I took all of that junk off as I did the throttle body mod. I followed RETed's writeup on his website, fc3s-pro. When I was done it ran like crap. Everything seemed cool with all of the vacuum connections so I broke out the trusty multi-meter (never leave home without one if you drive a FC) and reset the TPS. After that is was very nice.
sit car at idle, turn on headlights, blower motor, rear defroster, and if you have power windows try rolling them up/down, all at the same time... then to add to the fun abruptly press the brake pedal down. Without a BACV I would be shocked if the idle didnt fluctuate... assuming your idle is at a 'normal' rpm.
where does your car idle? If it's high you won't have as much of a problem, high enough and it won't matter at all.
02-28-2003, 07:10 PM
#30
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I'll try that when I'm warming up my car once I get out of the office tonight. For the past week it's been getting cold in Seattle (relatively cold). Well, cold enough to have a frosted over car in the morning. I sure don't miss living in the MidWest. I turn over the engine and it sparks to life like always. No stumbling at all when it's cold like that. I then turn on the heater to full blast and get the rear defroster (minus two lines in the middle ) going to defrost the windows. It doesn't seem to mind that at all. Like I said, I'll try that out. But so far my car did not inherit any of the problems like some other cars have once they took this stuff out. Beats me. It's not as though I did anything special.
