How do I get similar items from the Amazon Product Ads API?

I recently added Amazon Search to my site and am having trouble getting the full answer I want. In about 10% of my calls, I get zero images, although the Amazon site itself is showing numerous hits. Here is my call to their ministry:

results = Amazon::Ecs.item_search(query_text, {
    :search_index => 'All', 
    :response_group => 'ItemAttributes, Images, Offers',
    :item_page=>’1'
    })

      

        
        
        
      

    

90% of the time the results I get are just fine, but with any of the following query texts, this search returns 0 hits:

hoover bag 440004496 type S  

Citizen Women’s Stainless Steel Bracelet Watch 18mm EJ5850-57E          

mope space pack iPhone 5 

      

        
        
        
      

    

But when I go straight to Amazon.com and search for any of these goals, I get a lot of relevant responses.

What happens, for example, on Amazon displays, like "Your Search", the 440004496 type S vacuum cleaner "does not match any products" and then keeps showing "vacuum cleaner bag 440004496 type S" See all 322 results ... "and many good , relevant product matches that I would like to display on my page.

You can see the results (or lack thereof) on my website, www.FastForward.menu

How do I get these helpful responses through the API? Preferably in the same format as each completed initial answer item_search

? Preferably in the same call as in the original answer, so I don't need to write more syntax code?

There is a Similar Products API, but for that you need at least one product to transfer, which I don't have. See here: http://docs.aws.amazon.com/AWSECommerceService/latest/DG/SimilarityLookup.html

How do I get this list of "similar" products via the API so that my Amazon search doesn't appear completely empty about 10% of the time?

I'm sure others have come across this issue.

Please feel free to ask questions or make suggestions on how I can improve this question.