Missing and backfire

[BADCSL]

Hi guys.

I am having a problem with my csl as it is missing and backfiring with no power.
The car has not been used much this year and recently when I wanted to drive it, it began to idle unevenly and miss.

I began to think that it was the fuel that lost its power, I then added fresh fuel without draining the old. The problem did minimize but it's still doing the same.

I also noticed that there is a ticking noise when it idles. Sounds like a injector pulsating.

Any ideas guys that can assist me.

Thanks