I got around to replacing my fuel filter today, for no other reason than I wasn't sure when it was last done (being the 3rd owner of the car, etc and at 120K miles). Car has been running fine (stock with downpipe). Got the filter out, and the remaining fuel in it was a yukky brown colour. Bit like old rusty water in a garden hose - that couldn't have been good could it? Presumably the fuel in the tank is like that, so the new filter should be better at preventing all that brown gunk getting to the engine, but should I dump some sort of treatment into the tank, or drain the tank (I noticed when I was under the car there's a plug at the bottom of the tank) or just leave well alone... any recommendations?

 

IF you have water in the tank it will promote rust, gunk, etc. Of couse this could have come from a gas station with the same type problems in their undeground tanks. Either way you might consider running a few cans of fuel drying agent. This is similar to injector cleaner, but designed to remove water. Usually one bottle to a full tank of gas, then repeat. Won't harm you new filter, but then I'd recommend changin it again in a few thounsand miles anyway. Remimber, the rotory is not vary tolerant of running lean!

 

thats just the dirt and crud that the filter caught, sounds like it needed to be changed

 

Probably best to run the tank low and drain the last gallon or two out. Maybe pour in a couple of quarts of alcohol to mix with the water to help get it out of the tank.
I get a lot junk injectors come in for service due to moisture in the fuel system.

Gordon
WitchHunter Performance
Fuel injector cleaning & flow testing service