Disconnected Idle Air Control - for lower RPM after a cold start

[RH77]

Yeah, my biggest concern is the tranny -- it's the usual Honda 4-speed auto from the late 90's. I've been EOC-ing with it in Neutral without a problem (for quite a while), but with it dying in "Drive", I have concerns -- especially at 400 RPM.

It has all the fuzzy / hill-logic BS, which you have to trick to get it into torque lockup some days. I'm constantly shifting to selector to force an upshift, or use it to downshift, keeping RPMs well into the "fuel-cut" range -- better than brakes if you have to.

I kill the engine at most lights longer than 20 seconds. I don't usually look at other drivers since I'm focusing on the opposing yellow light and getting the gear selector ready to start, and force to 2nd.

My Wife was following me one day (met up and didn't know it) -- she was 2 cars behind at a light and heard the car starting up. I guess it's pretty loud If people see the car and stickers on the back, they get it. I'm just a "nutty, Liberal tree hugger in the Midwest, ".

RH77

Originally Posted by metroschultz

Short Answer, Yes.

Low rpm will still deliver adequate oil distribution to all your vitals in the engine, and in a manual trans.
Caveat to auto owners, most of the autos in passenger cars have a stall speed near ~ 1200 rpm.
This means below 75% or ~ 800 rpm there is not enough fluid pressure in the torque for operation. AND.
below 50% or ~ 600 rpm there won't be enough fluid pressure to lubricate the rotating assembly in the case.
I can't remember which tranny you've got, and they are not all identical. These are just rough numbers.

That Said,
Many newer cars use fuzzy logic in the controls for the engine and follow your particular driving habits to keep the rpm as low as possible at idle.

SOOO

For greater savings, lower idle is better, no idle (EO) is better still.

Since my car is three colors of blue with one black fender, I get many DIRTY looks when I restart at lights. toobad soosad yourdad,
they also hate me when I put in $11.5 at the pump and tell 'em I've been driving for three Weeks.

[metroschultz]

Go "Nutty Liberal Tree Huggers"
I watch everything, even started leaving more room in front of me for that occasion when i gotta get outta the way of some semi( thanks Darin)
we all watch for that opposing yellow, I have learned the light sequence of every stop I have to make. and i usually have to look up and through some other car to see the lights. "I see White People"
It sounds as if you might be starting to have some trans probs unrelated to EOC. I don't remember ever having to "trick" one of the Acuras into shifting. but I am NOT trying to diagnose problems from 700 miles away or lead you to believe your car is breaking.
Those trannys were/are pretty stout. but they are also expensive to replace. I saw an ad once, a million years ago, for a kit to put the lockup torque directly under your control via a switch on the dash. I can't remember where. but I think it was in one of my "tuner" mags.
I'll go back through the ones my wife hasn't thrown out yet and see what I can find.
Just ryin' to help.
Please don't read anything into this that's not here. S.

[Frank Lee]

Oh man, I'd love to have a switch on the dash for converter lockup!!!

[jazzie604]

extra note: the fast idle valve(coolant controlled) defaults to high idle. merely blocking off the coolant lines will actually guarantee a higher rpm, all the time. what you would have to do is get into the throttle body and physically block the ports. On my old eclipse, guys would take off the t-body and fab (usually with a pop can) a block off plate for the FIAV.

[dennyt]

I made an orifice plate for my IACV, out of a dime. Drilled a 3/16" hole in the center, filed the perimeter a bit so it was a tight fit in the inlet line, and voila! "High" idle on warmup is down from 2000rpm to 1100, without the driveability problems of disconnecting the IACV entirely.

[saand]

i made a idle air control restriction using a coke can and some holes, it was cut to size sandwiched inbetween the idle air control section and the throttle body.

I also just recently made an electronic circuit to control the electronic idle air control based on the RPM.
My car RPM is now down to 550 on idle even when cold.

It has made a good saving, not sure exactly how much though

[PLTWstudent]

You need the rich mixture to keep the cold engine running, feathering the throttle just gives it fuel. Get a block heater if you want to hit closed loop mode faster.

[cfg83]

dennyt -

Originally Posted by dennyt

I made an orifice plate for my IACV, out of a dime. Drilled a 3/16" hole in the center, filed the perimeter a bit so it was a tight fit in the inlet line, and voila! "High" idle on warmup is down from 2000rpm to 1100, without the driveability problems of disconnecting the IACV entirely.

It's probably already installed, but it would be neat to have pictures, or at least a diagram.

If it's on the inlet line, then I think you are saying it is :

inlet line -> orifice plate -> IAC control valve -> throttle body

CarloSW2

[dennyt]

CarloSW2, that is correct. The IAC has a 1/2" inlet hose, which is very easy to access. So, I drilled out a dime and stuffed it in the hose, right on top of the valve.



PLTW - I agree that a block heater is the better way, I have plans to install one. But until that happens, I'm reducing my warm-up idle speed (with this mod), and I've already put a resistor in parallel with the CTS to reduce cold-start enrichment. I have a knob on the dash, I can lean it out as much as I like when it's in open-loop.

Cheers,
-Denny

[cfg83]

Denny -

Great! Your 1.8 liter engine is close to my 1.9 liter engine, so I can look into this mod, even down to the 3/16" diameter opening.

CarloSW2