adapting an IACV from a 3sgte

[frogcow]

Looking over my IACV setup, trying to troubleshoot some idling issues,

I am using the IACV off a Toyota Caldina 3sgte engine. It is run by PWM at ~250 hz. It has a three pin plug with the centre pin a switched 12v supply, pin 1 controls an opening winding and pin 3 controls a closing winding.

Because MS2 V3.0 does not have capability to control both windings, I have read that what can be done is to use a resistor in series with the winding that closes the valve, this then allows the MS2 to control the valve by modulating the open winding. The resistor has to be chunky (50W 40ohm) as it is supposed to get quite hot. Mine isnt getting hot

There is a mechanical adjustment on the valve to adjust the full closed position, from factory the valve is left a little open at completely closed position. I have adjusted this to fully closed when closed.

The valve also has an inlet and outlet for coolant to flow through it if operating in very cold climates. I am thinking of removing these as the temperature does not get below 5 where I live.

I have also installed a diode between the switched 12v source and the winding controlled by MS2 banded end towards 12v source. What is this for?

My valve is working as I can hear it when I reduced the PWm down to 180 hz it started buzzing, I have also tried both 0 % and inverted and with both methods the car idles so I know I probably have something not set right.

[Matt Cramer]

If you check the FIDLE output in test mode, can it trigger a test light?

[rickb794]

The diode is to dump any flyback from the coil, and protect the MS.

I think someone said these setups operate with goofy numbers (other than 0 = closed and 100 open) like 30= closed and 70= open or some such.

[benckj]

I have a 3sgte running on MS2 with IACV. Will need to confirm PWM setting but mine runs well after stock setting were tweaked a tad. I also bypassed the coolant lines which keeps TB colder with air charge denser for forced induction set-up. No problem using this way even though our temps drop to -5c. The WUE settings in TS adapt for idle extra fuel well.

Jim

[frogcow]

Thanks for replies guys I have found my silly error, forgot to add a port in the adaptor plate for the iacv between the 3sgte TB and my intake, it was never plumbed in to begin with.

[rickb794]

Now that's embarrassing!

[frogcow]

Okay fixed that up. Resistor is getting warm now.

RSC - grounded via chunky resistor
+ B - switched 12 V Supply
RSO - wired to pin 30 MS2

I have diode across RSO and +B with banded end towards 12 V supply.

I can adjust mechanical spring to either close completely when 12v is applied or stay a fraction open when 12 volts is applied, what should I do here? And what PWM% should I run the valve at in idle cranking duty steps in Tunerstudio??

[benckj]

Stock set-up has the valve slightly open when energised. I closed mine off completely as I didn't want to create a boost leak.

Haven't checked my MS2 setting yet for PWM duty but think it was something like 8 (15hz step per unit) which equates to 120 cycles/sec. This may be different in MS2 compared to your version. Unlike your description mine was buzzing at the higher frequency and I dropped it down by 1 or 2 steps