An upstream filter is proving difficult. The good news is that that's not actually the only filter. There's a standard canister style that I'm currently halfway through replacing that's post-pump. However the line going from tank to pump is going to be basically impossible to filter any other way. It's primarily hard line, except for a small area of 1/2" soft line from the tank and another one at the pump. Both of which are small in length and to top it off, being 1/2" line there's basically no in-line filter I can easily find, let alone one that will fit in the small space. I'm starting to see why Mazda used this silly cone.
I think garage floor be damned and I'll be popping the drain plug today and hoping I have enough drain pan capacity for whatever comes out, but we'll see. For now it's more brainstorming during my lunch break
Well a few days later and I got some more time to work on the Mazda. First step is to drain the tank. This wasn't elegant with the tools I had on hand and the space I was working with, but was successful in dumping minimal stale fuel into the gravel floor of the garage
With the tank drained I could (surprisingly easily) drop the tank out and take a look at what horrors would face me.
Surprisingly, the horrors were limited. The tank had definitely been opened before.
The pickup tube was completely missing the mesh strainer that's supposed to be in-tank, so that explains why the tiny cone filter was clogging so quickly and easily.
Fortunately, the tank seems to be in astonishingly good shape inside, but the baffle was collecting plenty of bits of rust I suppose from sitting.
I tried calling a local radiator shop but they don't want to touch a baffled fuel tank to clean and coat it, so I think I'm on my own for it. My thought was to hit it with white vinegar and let it sit there for a day or so, then flip it upside down and do the same then wash it out. Not sure if I should throw nuts and bolts in like I have for motorcycle tanks as the baffle walls are pretty thin and I don't want to damage them.
I also need to figure out an in-tank filter option. Cruising the RX7club forums it seems some folks have put a cellulose filter in-tank from Aeromotive, and other folks have put a Jaguar in-tank mesh screen in. I'm leaning towards the latter as that's a more likely part to be order-able at a parts store, but I don't like either because they don't technically fit the pickup tube and need to have either JB weld or fuel hose clamped to the tube to actually fit the filter. Of course the Mazda part is NLA and the tiny cone filter that is torn I can't even find in a parts diagram, let alone find any sort of viable replacement, so I'm not fully convinced it's not a figment of my imagination.
I know plenty of folks here have run FBs so any insight from those with more experience would be very appreciated
