Sending Many Requests Hangs in Node - node.js

Question

I'm connecting to the Riot API to obtain images from their data dragon services using the Request package. Once the Request gives me a response, I save the image onto the disk. Saving champion thumbnails is a cinch; no problems. However, item thumbnails have been failing 95% of the time. It only occasionally works on my local machine.
I've been deploying the app to Heroku and the images were all successfully loaded the 4/4 times I deployed. Unfortunately, as stated earlier, when I run the server locally, my internet actually hangs and I become unable to use the internet only when I try to obtain the item thumbnails.
Here is a snippet:
function retrieveAndProcessImage(imageURL, callback) {
"use strict";
console.log(imageURL);
request(imageURL, {encoding: 'binary'}, function (req_err, req_res) {
// Extract the image name by looking at the very end of the path.
var pathArray = (imageURL).split('/');
var imageName = pathArray[pathArray.length - 1];
if (req_err) {
console.log("Couldn't retrieve " + imageName);
} else {
callback(imageName, req_res['body']);
}
});
};
The above snippet obtains the image from the API. When it occasionally works, the proper image is saved so I at least know that the URLs are all correct. The callback is just an fs.writeFile that writes the file locally so I don't have to send another request.
function retrieveAndProcessJson(dataURL, callback) {
"use strict";
request(dataURL, function (req_err, req_res) {
// Try to parse the JSON.
try {
var bodyJSON = JSON.parse(req_res['body']);
} catch (err) {
_errorMessage(dataURL);
return;
}
// If the parsing failed or the retrieval failed, connection failed.
if (bodyJSON['status'] !== undefined) {
_errorMessage(dataURL);
return;
}
// Otherwise output the success.
console.log("Connected to " + dataURL);
// Callback.
callback(req_res['body']);
});
};
The above obtains the raw JSON and passes the result of it to a callback.
fileFuncs.retrieveAndProcessJson(dataURL, function (raw_body) {
var bodyJSON = JSON.parse(raw_body);
_saveData(raw_body);
_saveImages(bodyJSON['data'])
});
and save images is:
function _saveImages(dataJSON) {
var filePath;
var itemKey;
var item;
var imageURL;
var imageName;
// Check to see the destination folder exists, and create if it doesn't.
fileFuncs.checkFolder(api_constants.itemThumbnailPath);
// For each item in the item JSON, save the thumbnail.
for (itemKey in dataJSON) {
if (dataJSON.hasOwnProperty(itemKey)) {
item = dataJSON[itemKey];
// The image are saved as #{id}.png
imageName = item['id'] + '.png';
imageURL = api_constants.itemThumbnailURL + imageName;
// Retrieve the file from the API.
fileFuncs.retrieveAndProcessImage(imageURL, function (fileName, image) {
filePath = api_constants.itemThumbnailPath + fileName;
fs.writeFile(filePath, image, { encoding: 'binary' }, function (err) {
if (err) {
console.log("\t" + fileName + " already exists.");
return;
}
console.log("\tThumbnail " + fileName + " was saved.");
})
});
}
}
}
I'd rather not have to deploy to Heroku each and every time I want to see what the changes in my code look like. Are there any solutions where I could potentially put some time between each request? Alternatively, just something that would let me do mass amounts of requests without hanging my internet.