Hi to everyone!
If i set all values in the base idle PWM table to 100 it has the same effect when i test the idle valve so will keep the valve fully open?
It's a Marelli 2 pin idle valve used in Cosworths and Fiats, by default it is closed.
100% PWM?
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Re: 100% PWM?
If closed loop is off, then yes.
Re: 100% PWM?
I can achive a good cold start if i directly open the iscv using a regular 2 pole switch.(100 pwm somehow does not open the valve fully).
Can i wire in a switched earth to the wire going from pin 9 to iscv? so i could overwrite the ecu during cold start?
Can i wire in a switched earth to the wire going from pin 9 to iscv? so i could overwrite the ecu during cold start?
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Re: 100% PWM?
There is also a max valve % setting, make sure this is set at 100 also
Re: 100% PWM?
I'm speculating here but isn't a 100% PWM duty going to provide a 50% opening? It is a solenoid / mechanical device that is required to open / close at anything between 20 - 60hz? and with best will in the world these are 'clunky' mech, devices that just don't match their expectations. Hence when switched, they can achieve 100% opening.gigford wrote:I can achive a good cold start if i directly open the iscv using a regular 2 pole switch.(100 pwm somehow does not open the valve fully).
Can i wire in a switched earth to the wire going from pin 9 to iscv? so i could overwrite the ecu during cold start?
If the OP can only achieve a good start with an 'actual' 100% open IAV, may I suggest adjusting the throttle stop screw to just crack the throttle blades and then trim down the IAV duty cycle to control the idle airflow?
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Re: 100% PWM?
100% PWM IS fully ON.
If whatever device is not functioning fully when you think it is 100%...then it probably isnt 100%. Test with a meter for duty cycle or on a scope.
If whatever device is not functioning fully when you think it is 100%...then it probably isnt 100%. Test with a meter for duty cycle or on a scope.
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Re: 100% PWM?
No. 100% duty cycle should open the idle valve fully. If it's not fully open with 100% duty cycle, then the device is faulty.katana wrote:I'm speculating here but isn't a 100% PWM duty going to provide a 50% opening?
As pointed out above, there are other limits that apply specifically to idle in DTA ECUs, with maximum and minimum duty cycle values allowed.
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