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Join Date: Oct 2004
Location: Charleston, SC
Posts: 410
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3.2 ICV question
Hi Pelicans, I am well into my megasquirt EFI project and coming up with many questions. Todays pressing question is, what kind of "valve" is the 3.2 Idle Control Valve. Is it a stepper motor or just an open closed switch?
thanks guys
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'79 SC-Silver Arrow 3.2ss-twinplug-EFI |
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11-21-2005, 11:40 AM
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Location: Novato, CA
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If I knew I'd tell ya, but I don't, so you'll just have to settle for a bump,
ianc
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BMW 135i. Nice. Fast. But no 911... "I will tell you there is a big difference between driving money and driving blood, sweat and tears." - PorscheGuy79 |
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11-21-2005, 06:08 PM
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Location: Charleston, SC
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Ok
Nudge nudge, wink wink, say no more...
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'79 SC-Silver Arrow 3.2ss-twinplug-EFI |
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11-22-2005, 05:28 AM
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Location: Charlottesville Va
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Not sure-it definitely isn't either "open" or "closed"-it occilates between those states. Does that help?
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Greg Lepore 85 Targa 05 Ducati 749s (wrecked, stupidly) 2000 K1200rs (gone, due to above) 05 ST3s (unfinished business) |
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11-22-2005, 06:03 AM
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Location: Charleston, SC
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Ok
Thanks Greg, sounds like a stepper motor?
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'79 SC-Silver Arrow 3.2ss-twinplug-EFI |
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11-22-2005, 06:26 AM
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Location: St Louis
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From the reading I've done (no experience) the DME sends a variable pulse width signal (ground closures) to the rotary solenoid on the valve. This current pulse train creates a magnetic field in the valve (looks like + and -, must have a default position at neutral?). The period of this pulse train is fast enough so that the dynamic variables in the valve (inductance, inertia, etc) average it out and it is a somewhat steady value i.e. it stays in one place.
The idle speed is a closed loop control with the DME. The DME doesn't "know" where the valve is positioned it just "knows" it wants more or less idle speed and reacts accordingly. |
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11-22-2005, 08:49 AM
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Join Date: Sep 2004
Posts: 10
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It's a PWM valve just like the VW's...fully supported with MS but may need a higher rated transistor to handle the current, especially on the V3 ECU's. Talk to Dave at www.fireandfuel.ca for more information as he knows these systems inside out.
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11-24-2005, 09:09 AM
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