My XT's fuel pump (an aftermarket generic Delphi) is failing miserably, so it needs replaced. My question: is there any sort of pre-filter/strainer/sock in the tank for the fuel pump supply, or is it just a bare pipe going to the pump? The FSM doesn't make any reference to a strainer of any type in-tank, and it would probably be good to know if one existed so that I can determine how to proceed with preparing the tank.

 

Also, the FSM does not mention a low-pressure filter being installed between the tank outlet and pump, but if there's no in-tank strainer, I suppose it's possible that the current pump ate some debris at some point. If anyone can confirm the lack of an in-tank filter, I will put on a filter with a new pump after the tank is cleaned and re-sealed (which is going to be fun...).

 

For reference, the bulby thing on the end of the factory pump is a fuel pulsation damper. It exists to ensure consistent fuel pressure and volume by smoothing out the supply to the injectors. Many people argue over whether or not it's really necessary (rx7club.com has many such threads) since the rubber lines and the fuel pressure regulator absorb some of the pulsation, but other people swear that the pulsation damper is absolutely essential, because the other components (especially the pressure regulator) would take too much stress without it, and why else would the factory put it there?

The dampers often have a service live of 100k miles and vary between $50-150 to replace. Their common failure mode is to develop leaks. On these cars it's not a huge deal, since the damper is located away from major ignition sources (and they're in the tank on some other models, so it's even less of an issue if they leak), but on the FC RX-7 the damper lives on one of the fuel rails on top of the engine, and leaks there have caused multiple engine fires.

the fuel pump on EA82s and ER27's has a sock, filter, screen, whatever you want to call it on it. It's integrated into the pump inlet so replacing the pump means you're replacing the sock/screen as well or removing it if the new pump doesn't have one.

That may explain why my relatively new-looking pump has failed: it doesn't appear to have any pre-pump filtration installed, and since it's generic I doubt it has a screen installed in the pump itself.

 

I'm considering a Walbro GSL-392 as a replacement, so will need a pre-pump filter. Any recommendations? I'm looking at K&N's 81-0231 or 81-0261, assuming they have the correct fitting size.