TI: Manual IAC/FIAV cold start block-off plate for TBs (7G)

[peanotation]

In the world of never-ending problems on 4 wheels, that is the financial nuclear bomb we've come to know and love as our 7Gs, I am testing interest for a manually-controlled idle air control valve.

If other people are like me and have ditched their IAC/FIAV assembly underneath the throttle body for a block-off plate, then you know the supreme glory and joy of a truly perfect idle. That is, after the motor is warm. We also know the pain of having to hold the throttle open until the car is warmed up, otherwise it would die.

Well, this is getting really annoying IMO. I'd love to be able to throw a friend my keys and tell them to warm up the car so they can get warm, and at least get the motor warm.

What I'm testing interest for is this: a manually controlled assembly underneath the throttle body that allows you to open or close one of the pass-through channels of air. If you already have the block-off plate, you're idle is already set, and opening the extra passage-way of air will raise your idle so you can literally walk away while the car warms up.

The hard part is building one strong enough to undergo boost. Building one for a stock 7G would be easy; all you'd need is a little motor with a rubberized plate that open and closes underneath the throttle body. For boost, it would just have to be super duper superman strong.

Imagine getting into your car, flipping a small hidden switch (this way it also helps prevent your car from getting stolen, pseudo kill-switch!) and enjoying 1500rpms while your car is warming itself up. After the motor is warm and you know it can idle on it's own, turn off the switch and you never have to worry about it the rest of the day, unless you leave your car off for half the day or something.

Discuss.

[DOHCstunr]

well on a MAS equipped car you would have to draw air from before the throttle, and deliver it post throttle, directly to the plenum.

On a speed density car like mine, all i have to do to raise the idle is run a fish tank bleeder valve from the plenum to my cabin, and (in order to not have a hissing sound in my cabin) the other side of the hose would run back through the firewall and would be left wide open(not running to anything)

fortuneatly for me, for whatever reason, with speed density and a full iac AND fiav block off plate, i have no idle issues at all... this is without the aid of an auxillary device.

If i rev it up and sidestep the throttle on a cold start. it will dip to about 700rpms and stabilize.

Matt you could use the exact same instrument I described above for your car. you'd just have to source a hose going from after the mas, and then splice it into one of your existing hoses, like the fuel pressure regulator or the back of the throttle body.


If you wanted to do it electronically, I would just use a normally closed solenoid.
like the EGR or the evap purge solenoid.

Step 1= go to the yard and grab a solenoid w/ electical connector from pretty much any mitsubishi...
step 2= wire the bitch up to a simple toggle switch make sure your power source is only hot when the ignition is at on. plumb it just as i described above with the mechanical valve
step 3= see how well it works.

you should use a normally closed solenoid so you do not burn out the solenoid by having it energized for 95% of the time you drive your car.
when the switch is off(preferably an "illuminated when active" type of switch) the solenoid will be closed and your car will idle at the speed set by your BISS.
when the switch is engaged, your solenoid will be open and will allow air to bypass the throttle.

it won't take much to give your idle a boost.
if 1 doesn't work, you could always use two and wire them parallel.

[peanotation]

omg you're a genius. i was into the throttle body idea cause the passage-ways are already there, two of them in fact.

but this way is easily boost friendly. i was gonna use the cruise control switch, since it's useless for me and already wired for a 12v send.

as for routing, i guess i could T into one of the lines coming off the throttle body ya? at vacuum it's all going to the same place anyways....

now the million dollar question is which solenoids are closed when power is disconnected?

[DOHCstunr]

Hmm. I'm not sure. Easiest way to find out is to put your lips on one and blow(this should be second nature to you Matt) if you can blow through it then clearly its normally open.
if you can't, (and even you matt wouldn't be able to suck or blow through one of these) then its a normally closed and exactly what you need.

You COULD always take the blockoff plate you have, and drill/jbweld some small fittings to the fiav section. and then route your solenoid/bleeder lines from one nipple-to the solenoid then solenoid-to other nipple
Mat you should know nipples as well.

this method if done properly would allow you to hide your cold idle apparatus.

[peanotation]

genius genius genius. i love it. i'm gonna JBweld the shit out of a nipple onto the underside of the blockoff plate. get the source nipple from the intake tube post-mas. GENIUS.