Slow on Server. Troubleshooting Help

Hi

I have created a website with WordPress and WooCommerce.

It runs fine on my local machine and also on a subdomain on my hosting.

However, when I upload it to my client’s hosting, the page load times vary from 1.5s (fine) to 30 seconds. It seems to be fine for a few minutes, then regresses into running really slowly. I can’t see a pattern (it affects all pages including pages with no WooCommerce, can be quick or slow regardless of whether cache is cleared etc). The pages always load in the end but seem to spend ages waiting for server response.

I’m guessing this is something on their hosting. I tried renaming the plugins folders, but aby which relate to WooCOmmerce come up with:

‘Response: 550 Access is denied. ‘

I don’t know if this is a related issue or not. I’ve since managed to disable the remaining plugins(after a lot of waiting for pages to load) from within WordPress but the site is still running very slowly with nothing on there.

The hosting company is absolutely useless. They don’t seem to have a clue what to do to troubleshoot. This is bulk hosting which my client can sell to other people. Is there anything I can likely do to troubleshoot this? Server logs, or anything like that? I really am not sure what I should be looking for.

Thanks

Mike