EFI University

[Wolf_Tm250]

Hi,
as the Delco is a very big and heavy idle valve, I wonder if it would be possible to use a 2 wire Toyota a/c idle up solenoid valve to control idle speed:
as anyone ever tried to control it via PWM?
Is it fast enough?
Thanks
_________________
TM enduro 250 2s.[55](2s is better than 4s)
Toyota Celica Gt-Four ST205 [588.25Nm@4957rpm]
EFI 101 + Advanced classes

[Buzzard]

It will probably not flow enough.

[Wolf_Tm250]

[Roberto Arano]

Any on-off valve can do PWM if the frequency is low enough, not sure how many cycles it will last though. WIll a combination of using it as an simple idle-up valve and idle timing control work? i.e near zero degrees at your idle target with increased timing below that target rpm to "push" it back up (commmonly used on cars without idle valves).
_________________
www.circuitse7en.net
http://stores.ebay.com/Circuit-Se7en

[Wolf_Tm250]

[giskard]

If the valve is operated with a PWM frequency of 500 Hz or higher, it may move linearly instead of clicking open and closed (which shortens its life). The problem I imagine is that the air metering may occur over a narrow range of duty cycle instead of over a large range, like a real PWM idle valve.

When you want a solenoid to move linearly, place a flyback diode across it. If you want it to open and close quickly, don't (and you want its off voltage to "fly" to 60V or so).

[mk3ukr]

[Wolf_Tm250]