TextQuery always return no result

[chrno1209]

Can anyone tell me on how to setup to make TextQuery (with highlight) works?
I did follow setting up as below but not success:

/config/ExamineIndex.config

<ExamineLuceneIndexSets>
	<IndexSet SetName="MyLookIndexSet" IndexPath="~/App_Data/TEMP/ExamineIndexes/MyLookIndexSet/" />
</ExamineLuceneIndexSets>

/config/ExamineSettings.config

<Examine>
	<ExamineIndexProviders>
		<providers>
			<add name="MyLookIndexer" type="Our.Umbraco.Look.LookIndexer, Our.Umbraco.Look" />
		</providers>
	</ExamineIndexProviders>
	<ExamineSearchProviders>
		<providers>
			<add name="MyLookSearcher" type="Our.Umbraco.Look.LookSearcher, Our.Umbraco.Look" />
		</providers>
	</ExamineSearchProviders>
</Examine>

Searching

var lookQuery = new LookQuery("MyLookSearcher");
lookQuery.NodeQuery = new NodeQuery() {
  Type = PublishedItemType.Content
};
lookQuery.TextQuery = new TextQuery()
{
    SearchText = searchQuery,
    GetHighlight = true
};

The result always return 0 while I checked in Look backoffice for the index, it has data.