idle trouble after deep puddle pass

[oab_au]

Originally Posted by Kiss Me Deadly

I was not able to unplug it on idling car, but i unpluged it before start and again nothing happened, 1250 on P, N, 1000 on other

Well mate it is in that area, either the valve itself or the way the ECU is controlling it. Really need a select monitor, to see what the ECU is doing with the control signal.
You could try adjusting the valve closed a bit more, see if that changes it, but if it is the ECU that is holding it open, it may just take it back up to the higher rpm idle, but at least that may tell us a bit more.

Harvey.

[newsvx]

Try this ...
The By-Pass Air Control Solenoid Valve, or Idle Air Control Valve, allows the Engine Control Unit, to control the inlet of air to the engine, in order to govern idle speed when the throttles are shut. One obvious function is to increase the airflow in order to maintain idle when the air conditioning system imposes an extra load on the engine.

During engine starting, when extra air is required, the Engine Control Unit operates an additional valve, i.e. the Auxiliary Air Control Valve.

The by-pas unit comprises a rotary solenoid valve, biased towards a central rest position by means of a permanent magnet. A double wound coil provides open closed operation from a mean rest position, at which point the valve is half open. This arrangement provides a means of two way variable control towards open or shut, depending on the way voltage is applied.

Adjustment of the rest position is provided by incorporating slotted screw holes in the housing, no doubt to allow the position to be set during assembly, in order to allow for anticipated manufacturing tolerances.

Three electrical connections are involved. The centre pin on the connector is common to both windings and is energised positive. The remaining two connections provide for open and close operation of the valve via negative polarised control circuits.


Cleaning and Adjusting.

Cleaning is best achieved by removing the solenoid coil by undoing the two attachment screws, which pass through the slotted holes which provide for adjustment. Make a scratch mark, so that the original position can be retained after reassembly. Magnetic force will be apparent as the solenoid coil is separated from main body.

The armature which rotates in ball races, should rotate open closed with very little resistance, when moved by hand. The valve should be cleaned of foreign matter using a suitable solvent/lubricant so that is completely free to move.

After reassembly the valve should rest in a position half open and half closed, when set to the original mark. If there is a significant discrepancy, this may indicate that the setting has been tampered with at some time and it should be reset.

Testing.

The solenoid resistance should measure nine ohms, each side of the common connection, i.e. 18 ohms overall, a small tolerance being acceptable.

With positive to the common connection, 8 volts DC applied alternatively to the two remaining connections, should fully open and close the valve from rest. Return to the rest position should occur reliably without hesitation. In the event that only 12 volts is available, this will suffice for intermittent testing, but the extra torque available must be taken into account.

If a variable voltage supply is available the variable movement of the mechanism can be demonstrated, but this can be assumed OK after a satisfactory simple fixed voltage test.
This from a friend in New Zealand .....
Harry

[SURTEESS]

Not me - and I am in NZ.

I think it is our old friend Trevor who has great knowledge on SVX cars and has already outlined this issue in an earlier posting ......

[Kiss Me Deadly]

Well, the problem solved.
Firstly, i replaced IACV with another one - normal idle came back, but few times car died after long driving or driving with full load (A/C max, etc), and few times it was necessary to tap accelerator to start

Finally, i had dissambled my old IACV (i made 4 scratch marks before dissambling and unscrewed 2 screws), removed rust and sh!t from magnet, unjamed bearing, lubricated it with silicon grease and assembled back. Put it back to TB.

Everything is fine, thanks everyone for help!

[oab_au]

Whoo hoo,
You have done well Gleb, not easy to do over there.
Though it was a long way around to get back to the first things.

Harvey.

[SURTEESS]

" Your thanks addressed to all of those involved involved is very much appreciated.

Not so hard when one knows exactly how stuff works. LOL. Good that detailed information from New Zealand enabled you to completely dissemble things and fully overhaul the original valve.”