How to add product programmatically for custom guest Quote in Magento 2

Please let me know how to add product to cart programmatically for custom guest user quote using an event observer in Magento 2

I try to add product for the registered user it was added successfully but when i added product for guest user in quote it was added with 0 base_price on checkout_cart_save_after event.

Here is the code

$quote = $this->checkoutSession->getQuote(); 
$items = $quote->getAllVisibleItems();
$newQuote = $this->quoteFactory->create(); //MagentoQuoteModelQuoteFactory;
$store = $this->storeManager->getStore(); 
$storeId = $store->getStoreId(); 
$newQuote->setStore($store); 
$newQuote->setCustomerIsGuest(1);

//$customerid = $quote->getCustomerId(); 
//if($customerid){ 
// $customer = $this->customerRepository->getById($customerid); 
// $newQuote->assignCustomer($customer); // }
 foreach ($items as $item) 
{
 $productId = $item->getProductId(); 
 $_product=$this->productRepository->getById($item['product_id']); 
 $newQuote->addProduct($_product,intval($item['qty']));
 $newQuote->collectTotals()->save(); 

}