Intermitting starting

Hi:

When this happens, does the starter motor fail to engage or does it work but the engine won't start?

If the starter always works, here is what I need you to do. When it won't start, I need you to try starting fluid to see if it starts. If it does and then stalls, we know it is a fuel related issue. If there is no change, I need you to check for spark at the spark plugs. Here is a link that explains how it's done.

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

Let me know what you find.

Joe