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Old 02-10-2008, 03:39 PM
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Trevor Trevor is offline
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Join Date: Feb 2002
Location: Auckland, New Zealand
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Quote:
Originally Posted by longassname View Post
The idle must also be raised to the neighborhood of 800 rpms. I will release matching engine management software with an adjusted idle and transmission control unit software with high rpm shift points shortly.
Have you tried raising the idle speed by simply resetting the set point on the BPACSV rotary solenoid?
To save typing I have extracted text from my earlier write up.

The By-Pass Air Control Solenoid Valve, or Idle Air Control Valve, allows the Engine Control Unit, to control an adjustable inlet of air in order to control idle speed when the throttles are shut. One obvious function is to increase the airflow when the air conditioning system imposes an extra load on the engine. The SVX has a second valve, The Bypass Air Control Valve, to supply extra air during cold starting.

The unit comprises a rotary solenoid valve, biased towards a central rest position by means of a permanent magnet. A double wound coil provides reversing open closed operation from a mean rest position, at which point the valve is half open. (Presumably the normal static idle position.) This arrangement provides two way variable control, dependent on the applied voltage.

Adjustment of the mean position is provide for by incorporating slotted screw holes in the housing, probably to allow the position to be set during manufacture in order to allow for anticipated tolerances.

N.B. Edit ---- Having had second thoughts, there are reasons why this will not work, because the ECU will always try to adjust the AACSV in accordance with the idle speed fixed by the software. But what if the valve is modified/adjusted so that it can not completely shut off air to the point where the engine stalls? I seem to recall that an a mechanically adjustable auxiliary overriding air bypass was discussed at one point, I understand with some success.

What would occur if the closing signal is inhibited by means of a resistor or completely disconnected, then the minimum idle set by adjusting the ACASV? The opening signal should continue to operate to adjust for extraneous loads and there would be a fixed low idle, but the ECU would have no control over the minimum idle. Admittedly this could maintained as accurately.

If the connecting tubes were temporally extended, experiments could easily be carried out and be worthwhile.
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Last edited by Trevor; 02-10-2008 at 04:50 PM.
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