Hijacked my IAC

[Gloyale]

Well, not hiJacked...just stole control from the ECU.

 

I got sick and tired of my EJ high idling and surging AFTER it's already warmed up on restarts. Additionally, I've wanted to add a manual "idle up" setup for running an inverter, jumpstarting, slow mud/snow crawls.......so.......

 

I cut the wires that ground the "open" and "closed" side of the IAC (pins 1 and 2 of the largest ECU connector) This caused a CEL, and poor running (fuel cut to #1 injector) so I wired 12v o the ground side of 2 fillamnet amber bulb (legacy turn signal) and each of the elements to the cut ECU wires. Now the ECU has a load to turn on and off that simulates the IAC. And it gives me a nice footwell light.

 

After that, the CEL is gone, but now the IAC was "uncontroled" and it high idled wildly.

 

Next step, I wired each side of the IAC to it's own Grounding switch.

 

I can switch on just the closed side to bring the idle down to 700 rpm.

 

I can switch on just the OPEN side which gives me over 3000 rpm.

 

Or I can switch on both sides and get a nice 1800-2500 rpm range.

 

 

Only down side is remebering to Open the IAC for cold starts, and then close it again after I begin driving. But I can tell I am saving gas....because before I would be drivng for almost 20 minutes before it would idle down. It was annoying sitting at a light with the engine turning 2500 rpms. Now I can kick it down, or up.....anytime I want. I can post pics if anyone interested.

 

 

Remembering to turn on the "open" side of IAC.........mildly annoying

 

Remebering to close it after driving........Small adjustment

 

Having an instant flip of a switch Idle up..........priceless.

Edited February 27, 2010 by Gloyale

[The Beast I Drive]

I think it would be benificial for what you are trying to do with it if you wire a potentiometer into the circuit for the high idle, that way it really would be just like a throttle lock, and you woud have infinite RPM adjustment within your 700-3000+ rpm range. Just a though, cool idea, stealing control from the computer is awesome

 

-Bill

[Gloyale]

I think it would be benificial for what you are trying to do with it if you wire a potentiometer into the circuit for the high idle, that way it really would be just like a throttle lock, and you woud have infinite RPM adjustment within your 700-3000+ rpm range. Just a though, cool idea, stealing control from the computer is awesome

 

-Bill

 

Yeah......I have an old fuel tank level sender that may find it's way into the circuit.