[k9handler]

the fuel tank treatment is available from POR direct, and it's pretty simple as you just follow the instructions. The total project takes at least 72 hours (The tank treatment has a cure time) so it's not a simple two day job. The fuel filter is no big deal, unscrew it and put in a new one. My car was a CIS car at the time, so your MFI parts may be different. For example my car also had a small screen filter in the tank that was completely rotten with rust, you can buy a replacement part...but I just removed it as the fuel filter seems to be enough.

I would work on the spark/fuel issue first as that is more than likely the issue.