Adzn3k Posted June 1, 2019 Report Share Posted June 1, 2019 Hi guys, I'm have real issues getting my Idle below 1300 on my celica gt4 st205 with caldina intake manifold and throttle body. It's a 3 pin iscv, I have it wired correctly Pin 1 (top) = signal Pin 2 (middle) = 12v Pin 3 (bottom) = ground When plugged in and tested it buzzes and even effects the idle but even with the duty set as low as 10 it will not drop the idle below 1300 when up to temp. If I unplug it, the idle is 1300 when up to temp. I have had it on the bench and it looks like the valve naturally sits half open with no power. If the 12v and ground is connected it still sits half open, if I tap the signal to ground it closes for a split second then opens again even if the signal stays on ground so it needs to be repeatedly tapped for it to close again. Am I right in thinking if the duty cycle was turned right up to 80%+ would this reduce the idle or am I barking up the wrong tree? I really need to figure this out, it's not just my car either I know of 2 other guys in the same boat as me Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 1, 2019 Report Share Posted June 1, 2019 I dont have any specific experience with that valve, but here's what I suggest: As a test set the aux it is connected to to "GP PWM" like my example below. With the valve unbolted from the engine but still plugged in you can then highlight the whole PWM table and command different duty cycles and observe what DC's give you fully open and fully closed. Once you have that info you can use those values as your minimum and maximum clamps in the idle control settings. Some solenoid valves fully closed is about 20% DC. Quote Link to comment Share on other sites More sharing options...
Adzn3k Posted June 1, 2019 Author Report Share Posted June 1, 2019 OK thanks I'll give it a go tomorrow and report back Quote Link to comment Share on other sites More sharing options...
Adzn3k Posted June 2, 2019 Author Report Share Posted June 2, 2019 so i've been out done exactly as you put in your example and 100% the valve is fully open and no matter how low you put the duty cycle it does not close. There is a slight amount of adjustment by undoing 2 bolts and twisting it but it still doesn't fully close. I'm completely baffled with it as it would close for a split second when i tested it on the bench when i tapped the signal to negative. Quote Link to comment Share on other sites More sharing options...
Toliski Posted June 2, 2019 Report Share Posted June 2, 2019 On 6/1/2019 at 9:28 PM, Adzn3k said: Hi guys, I'm have real issues getting my Idle below 1300 on my celica gt4 st205 with caldina intake manifold and throttle body. It's a 3 pin iscv, I have it wired correctly Pin 1 (top) = signal Pin 2 (middle) = 12v Pin 3 (bottom) = ground When plugged in and tested it buzzes and even effects the idle but even with the duty set as low as 10 it will not drop the idle below 1300 when up to temp. If I unplug it, the idle is 1300 when up to temp. I have had it on the bench and it looks like the valve naturally sits half open with no power. If the 12v and ground is connected it still sits half open, if I tap the signal to ground it closes for a split second then opens again even if the signal stays on ground so it needs to be repeatedly tapped for it to close again. Am I right in thinking if the duty cycle was turned right up to 80%+ would this reduce the idle or am I barking up the wrong tree? I really need to figure this out, it's not just my car either I know of 2 other guys in the same boat as me If I remember correctly with my St205 valve the pins were, open, 12v, and close. I don't know if st215 is different but I believe the pins were the same. The valve controls by ground the open and close pins. Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 2, 2019 Report Share Posted June 2, 2019 Yeah, I agree with Toliski here, I suspect this is a two coil open/close signal type valve, not a single solenoid like you think. Can you get a multimeter and measure the resistance between the three pins. Quote Link to comment Share on other sites More sharing options...
Toliski Posted June 2, 2019 Report Share Posted June 2, 2019 Even at Ecu pinout has RSO (iacv open) RSC (iacv close) and center 12v. The valves have the same working style even if they were different I can confirm that. Quote Link to comment Share on other sites More sharing options...
JMP Posted June 2, 2019 Report Share Posted June 2, 2019 I've got tons of experience with these valves, same as is used on the 1zz, 2zz and v7-9 WRX's. Take the screws out so the back manget/connector section can be removed and check that the mechanism spins freely. It's really common for them to gum up or even become rusted internally and then it doesn't matter what you do trying to control it you will fail. I run then at 250hz and usually need something like a 20% duty control range. Eg, low temps around 60% duty and operating temp around 40% Edit: It may be a two coil type as posted previously, simple enough to check but still worth checking that the control mech can spin freely Edit again: Looking at the ST215 3sgte EWD, the valve only has 1 control wire like the 2zz, 1zz etc. Quote Link to comment Share on other sites More sharing options...
Tiz Posted June 4, 2019 Report Share Posted June 4, 2019 As above, I find these nearly always need to come off and be cleaned and WD40 run through them whilst in test mode at 10hz then the work correctly. Quote Link to comment Share on other sites More sharing options...
Adzn3k Posted June 4, 2019 Author Report Share Posted June 4, 2019 So I bought another icv from a different car that had no idle issues and it's still the same as the one on the car, it naturally sits half open and closes for a split second when the signal is put to ground. My cars not here to test it but I'm expecting the same outcome which will be high idle Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 4, 2019 Report Share Posted June 4, 2019 On 6/3/2019 at 9:53 AM, Adamw said: Yeah, I agree with Toliski here, I suspect this is a two coil open/close signal type valve, not a single solenoid like you think. Can you get a multimeter and measure the resistance between the three pins. Did you measure the resistance yet? Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 4, 2019 Report Share Posted June 4, 2019 Actually, looking at your first picture and your described pinout I think you have it wrong. Pin 3 would be the top pin wouldnt it? You say it is the bottom. Here's connector pic from ST215 manual: Same orientation as this: Quote Link to comment Share on other sites More sharing options...
theFiztec Posted June 7, 2019 Report Share Posted June 7, 2019 I'm using the same idle valve together with 1zz throttle body on my daihatsu K3-VET. it runs with no issue. My Wiring is ; 1) RSO (1) to Link AUX 2) B ( Battery 12V Switched/Ign) 3) RSC (3) GND Here is my idle table DC Quote Link to comment Share on other sites More sharing options...
Adzn3k Posted June 7, 2019 Author Report Share Posted June 7, 2019 I got my car back last night I will have a look at this after work today Quote Link to comment Share on other sites More sharing options...
Adzn3k Posted June 21, 2019 Author Report Share Posted June 21, 2019 Only just managed to get round to checking all this and swapping the pins round did the trick Thanks for all the input people I now need cure a fuel leak haha Quote Link to comment Share on other sites More sharing options...
Aqmar Posted November 23, 2019 Report Share Posted November 23, 2019 Any updates on this? Did u manage to solve the issue? Quote Link to comment Share on other sites More sharing options...
Adzn3k Posted November 23, 2019 Author Report Share Posted November 23, 2019 I followed the above advice and it worked Quote Link to comment Share on other sites More sharing options...
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