Replace fuel filter before or after injector clean

[cjv998]

Hi everyone. I have an '01 Miata with 81k miles, and I plan on running BG-44K fuel system cleaner through it (looks like that's one of the best cleaners on the market, right? I stick to Chevron or Shell gas, but who's to say that the previous owner didn't put garbage in it?) However, my Miata is also due for a new fuel filter, which brings me to my question: should I replace the fuel filter before or after I run the injector cleaner through that system?

One side of me says to replace the filter first, so all the gunk in the filter doesn't get dissolved and have to get passed through the injectors.

But another side of me says to replace the filter afterwards, because the existing (already gunked-up) filter will trap any debris that gets loosened from the tank.

So, any thoughts? Thanks!


Also, one more quick item: could you guys do a quick look over the fluids I plan on using in the Miata? I'd really appreciate it!

Motor Oil: Mobil 1 10w30 with Mobil 1, Wix, or Purolator filter (whatever I have available)
Antifreeze: Zerex Asian vehicle formula
MTF: Redline MTF
Diff (Torsen LSD): Redline 75W-90
P/S: Redline synthetic P/S fluid

 

[Falcon_LS]

Might be an idea to 'prime' the fuel filter with BG-44K prior to installation, so that's the first thing that's sprayed through the injectors, and dump the rest in the tank.

 

[mechtech2]

I'd replace the filter after wards.
Crud that is loosened on the pickup side - the gas tank side -will be caught there.
Anything dissolved would pass through either a new or old one.