hey all can anyone one with a gregories or other relievant manual, tell me what the resistance of the IAC should be? and if its listed what voltage it works off? :bow: Cheers
Having a quick look, the IAC valve has 4 wires - one light green/white - one light green/black - one light blue - one light blue/black. There should be a resistance between the light green/white and the white green/black and a resistance between the light blue/black and light blue. The resistance should be between 40-80 ohms. The terminals with black on them should be shorted to the chassis, another thing to check. Im not 100%, but I think she runs on 12V. Gregorys runs through a great test procedure if you are having trouble with it.
thanks for that kopper69, nar no probs, gonna do some calculations see if i can split the wires for it for my manifold, dual IACs with out drawing too much current n frying my ecu! ur a legend!
You can't realy spilt the wires, it's a stepper motor and needs all 4 to operate. If you are making a twin TB run the IAC on one TB and have a plug made for the other IAC position.
Sounds interesting. If you need any help running 2 IAC valves from the one signal let me know, will give you some help.
thanks kopper69, my plans are in the thread below, V6 mod n dev. i just might take you up on the offer!! http://forums.justcommodores.com.au/showthread.php?t=49076 jc58nc, im working on a dual plenum manifold, so i unfortantely cant just block up one hole coz one bank wont be getting any air. i wanna run a second IAC, splicing rather, to run it, i know running them in parallel will up the current, but i may be able to drop a few more resistors in series to drop the current to bout normal, just may loose a lil voltage.
what if you put a pipe from one plenum to the other plenum with a T peice in the middle with an iac on the T letting idle air to both sides but using one IAC shouldnt effect the duel plenums much if you choose the right size pipe say 4-5mm inside diameter.
or make a couple of fittings that fit where the normal iac's fit and do the same thing with a bit of pipe a T peice and an iac into the iac holes
Dont quite understand the resistor idea fully, but from your description, I dont think its going to work. Your logic is good, stop the ecu working to hard, burning itself out, costing you a bag of $. Problem is, the valves are probably going to want a bit of current, to do there thing, and they are probably designed to work at that voltage. Using a resistor is going to help the ecu, but you will probably find that the valves arent going to work properly or completely. I would recommend using a mosfet or relay. That way, ECU still sees pretty much same thing, one IAC valve going. Im not sure how the ECU would handle driving two, it might do it no problems, but I wouldnt spend my $ finding out. A FET or relay will simply detect a signal and apply a direct 12V. Your only problem is going to be if the ECU is putting out different voltages, to drive the valves. Im not sure, would have to do some research, let me know if you need any help with this. If that is the case, and the IAC is jumping all over the place supplying 2.3V,-4V etc etc and everywhere, you are going to have to get a little more creative, maybe get an op-amp (IC) setup, or try running both straight from ECU (insert disclaimer here). This might sound a little confusing, please let me know if you get stuck and I will help you out.
spanners, the only problem is with ur theory (i had thought of that too ) is becoz is like a worm hole with the IAC controling flow, i would need 2 pipes from each TB, one air in (outside air b4 IAC), IAC, then air return (IAC to plemun) would have to get to pipes welded onto each TB.. kinda messy, or 1 air in, IAC, 2 return lines.. Kopper, thinking amp of some sort, to boost voltage above 12v so the resistors dont drop the voltage below it, (havent worked out the voltage needed yet... thought of relay but not adjustable voltage though there like u mentioned. gonna "paint" up a pic of resistor values and diag to show my thoughts.. ESP's not working atm thanks for your thoughts all
To setup the two IACs you can use 3 transistors to act as switch drivers, they would be driven by the ECU and handle the extra current. The IAC motors step with 12 volt pulses to each of the 3 wires in turn and one is earth, to change direction the pulses go the opposite direction on the 3 wires. Jaycar had a 12 volt light chaser a few years ago, I used one of those circuits to control the idle up or down with a switch in a Toyota Supra twin cam I modified, I know the drivers in that circuit would handle 1.5 amps each.
thanks jc58nc, i've worked out it roughly uses .24amps atm but will double to .48amps with another IAC on that pair of wires (another pair also taking that current) measured my iac valves pairs 50ohms each transistors may be the best bet, havent done much with transistors apart from installing them (soldering). any more info you have on setups would be greatly appreciated.
bit of an update.. i've found a program that u can design in and see voltages n stuff.. still have to work on if any resistors or the such are needed, below, attached is the same diagram but in simulation of when the iac is voltage reversed. only one pair of wires atm but will duplicate it for the second set (4 wires) i've put LEDs in instead of an inductors (what is actually in the IAC) so i could see if its working now what im needing ur imput is will this be successful? can u see any flaws? please feel free to pick the sh1t outta it
I was thinking like this wouldnt be to hard to turn up a iac valve seat on a lathe and use the one iac
spanners i was thinking along the same lines.. but thought it might have looked messy but that may have to be the best way to do it.. Cheers mate
put it right at the back hidden down the bottom somewhere or right up by the throttle bodys it wouldnt be that big in the end the iac isnt that big .tuck it in some where
