resetting base idle

[moff_man]

quick question. does anyone know how to reset the base idle on a vs v6? i use the tech 1 but i don't have the luxury this time.

[wraith]

3000 RPM for 10 seconds.

[Cheap6]

There are very few reasons why you should have to adjust the base idle - only engine mods, otherwise fixing whatever it is that is causing the low base idle speed is preferable.

Clean the throttle body and IAC valve pintle first. Do not use carb. clean for this! (Use kerosene and a cloth.)

If you insist try:

Mark the current position of the idle stop screw so you can get back to where you started if you change your mind.

Engine at operating temp., accessories and cooling fan off, park or neutral.

Create a vacuum leak sufficient to cause the PCM to completely close the IAC valve eg. pull the line to the brake booster.

Disconnect the connector to the IAC motor to lock it in the closed position and refit the vacuum hose.

Bridge the diagnostic connector terminals, same as checking for codes, to lock the igntion timing.

The base idle speed should be 450-550rpm. The engine will nearly stall at this speed.

[TheIceman]

3000 RPM for 10 seconds.

no, this is not how you reset base idle.

[juzzyx]

When I start my VS it idles to 1600 then slowly falls for about 5sec back to 900. Is that normal? 158000kms on the odo.

[Brett_jjj]

In the VS manual is says-Make sure the IAC and its ports in the throttle body are clean .Ensure the throttle valve moves freely and returns to fully closed position.Run the engine until its reached operating temperature.While the engine is idling,ensure the engine cooling fan and all accessories are off. Disconnect the wiring from the IAC valve at the same time the ignition is switched off.Open the throttle slightly and start the engine.After the engine starts,slowly allow the throttle to close.If the engine stalls,adjust the base idle screw one half turn and start the engine again.After the engine has been idling for 2 minutes,check the base idle speed ensuring the engine cooling fan is off.If the base idle speed is not 500-600 RPM,adjust the base idle screw to achieve a base idle speed of 450-550 RPM.Stop the engine and connect the wiring connector to the IAC valve.Start the engine and after 5 seconds check that the idle speed is to specifications.Hope this helps.

[wraith]

Yeah I was half asleep and misread OP's post. Feel free to ignore it.

[moff_man]

thanks guys, but its seems to be a lazy iac, or a crook coolent temp sensor. the iac is very noisy and it idles very high hot or cold for 30sec, once started also injectors and t/b have been replaced and cleaned

[astormsau]

Hi Moff did you end up sorting this out?