Set idleTimeoutAction from octopus

I am working on building scripts to set my startMode and idleTimeoutAction from octopus. My script is changing the startMode correctly, but I keep getting errors with the idleTimeoutAction. Can someone help me?

Here is the error i'm getting:

Executing script on 'APPSWDEV01' Setting LeadsAPI property startMode to AlwaysRunning Old value AlwaysRunning New value AlwaysRunning Done

Setting LeadsAPI property idleTimeoutAction to Suspend System.ArgumentException: Property ("idleTimeoutAction") is not found on \APPSWDEV01\AppPools\LeadsAPI. Parameter name: providerSpecificPickList at Microsoft.IIs.PowerShell.Provider.ConfigurationProvider.GetProperty(String path, Collection`1 providerSpecificPickList) There was a problem setting property

# Running outside octopus
param(
    [string]$APIName,
    [switch]$whatIf
) 

$ErrorActionPreference = "Stop" 

function Get-Param($Name, [switch]$Required, $Default) {
    $result = $null

    if ($OctopusParameters -ne $null) {
        $result = $OctopusParameters[$Name]
    }

    if ($result -eq $null) {
        $variable = Get-Variable $Name -EA SilentlyContinue   
        if ($variable -ne $null) {
            $result = $variable.Value
        }
    }

    if ($result -eq $null -or $result -eq "") {
        if ($Required) {
            throw "Missing parameter value $Name"
        } else {
            $result = $Default
        }
    }

    return $result
}

& {
    param(
        [string]$APIName
    ) 

    if (![string]::IsNullOrEmpty($APIName))
    {
        Write-Host "Setting $APIName property startMode to AlwaysRunning"

        try {
             Add-PSSnapin WebAdministration -ErrorAction SilentlyContinue
             Import-Module WebAdministration -ErrorAction SilentlyContinue

             $oldValue = Get-ItemProperty "IIS:\AppPools\$APIName" -Name "startMode"
             $oldValueString = ""

             if ($oldValue.GetType() -eq [Microsoft.IIs.PowerShell.Framework.ConfigurationAttribute])
             {
                 $oldValueString = ($oldValue | Select-Object -ExpandProperty "Value");
             }
             else 
             {
                 $oldValueString = $oldValue
             }

             Write-Host "Old value $oldValueString"
             Set-ItemProperty "IIS:\AppPools\$APIName" -Name "startMode" -Value "AlwaysRunning"
             Write-Host "New value AlwaysRunning"
             Write-Host "Done"
        } catch {
            Write-Host $_.Exception|format-list -force
            Write-Host "There was a problem setting property"    
        }

        Write-Host "Setting $APIName property idleTimeoutAction to Suspend"

        try {
             Add-PSSnapin WebAdministration -ErrorAction SilentlyContinue
             Import-Module WebAdministration -ErrorAction SilentlyContinue

             $oldValue = Get-ItemProperty "IIS:\AppPools\$APIName" -Name "idleTimeoutAction" 
             $oldValueString = ""

             if ($oldValue.GetType() -eq [Microsoft.IIs.PowerShell.Framework.ConfigurationAttribute])
             {
                 $oldValueString = ($oldValue | Select-Object -ExpandProperty "Value");
             }
             else 
             {
                 $oldValueString = $oldValue
             }

             Write-Host "Old value $oldValueString"
             Set-ItemProperty "IIS:\AppPools\$APIName" -Name "idleTimeoutAction" -Value "Suspend"
             Write-Host "New value Suspend"
             Write-Host "Done"
        } catch {
            Write-Host $_.Exception|format-list -force
            Write-Host "There was a problem setting property"    
        }
    }

 } `
 (Get-Param 'APIName' -Required)

I had a look at the file C:\Windows\System32\inetsrv\config\applicationHost.config which contains app pool settings. When an idleTimeoutAction is manually configured on an application pool, the result is an entry like:

<add name="MyAppPool" managedRuntimeVersion="v4.0">
    <processModel idleTimeoutAction="Suspend" />
</add>

From PowerShell you can access the idleTimeoutAction property via the command:

Get-ItemProperty "IIS:\AppPools\MyAppPool" -Name processModel.idleTimeoutAction

Likewise, you can set the idleTimeoutAction property via:

Set-ItemProperty "IIS:\AppPools\MyAppPool" -Name processModel.idleTimeoutAction -Value "Suspend"

Hope this helps.