Yeah, getting the old one out is hands down the hardest part. Again, the big trick is WD-40 so the hoses come off easily and using the right sized pliers to get the hose clamps moved back.

Dale

I have our manual car sitting dead, up on four jack stands at the moment while I do an engine rebuild.

This is the perfect time for me to slide under the rear of it and "practise" removing the filter. It has a new filter, but my father (72 years old) actually put it in, not me. I have never done one of these filters before.

Once I'm happy I can do it on the manual R1, I will then walk over to my own automatic car and attack it with confidence. Because the filter in my automatic car is original and never been changed..

I have faith you can do it :). Lube and the right tools is the big trick on the job.

Dale

I just got my Fd and I think this will be one of the first things on my to do list. 93k original miles and no record of it being done before I got it

Dale,

I have no idea how you accomplished this freaking task at all. I read your steps and decided to try it, since the fuel filter was changed ~50K miles ago by a dealer.

I bought (a set of) hose pliers, 1/4" drive 3" and 6" extensions, a brand new 10 mm socket, a new fuel filter, and had everything else I needed, even an LED "headlamp" so I could see. In 20 minutes, I had the car on jack stands, the passenger side under-shield off, and was hunting for the old filter. I finally found it, exactly over the top of the differential housing, nearly trapped between it and the fuel tank.

I could see the near end of the filter and its hose, and that was it. I reached up to try and feel the mounting nuts, and I think I felt them on a couple of forward-facing studs, but could not feel any way to access them. Maybe coming from the front with an extension? Nope, the curve of the filter body was in the way of accessing the nuts from a socket on an extension, as far as I could tell by feel. Worse, it felt like there would be no way to start the nuts later.

Plus, the filter I bought from Malloy is a N3A1-13-480 which has no mounting bracket, not the N3A1-20-490 (shown with bracket) that is in the 1994 parts catalog. That meant that, even if I could somehow magically remove the old filter's mounting nuts, I would have to remove the old bracket, put it on the new filter, and hope that I had aligned it perfectly for the studs on the chassis. Then I would have to somehow get the mounting nuts back on those two studs, and I can see/feel absolutely no way to do that.

I was not about to attempt removing the fuel hose on the near side of the filter without having (at least some) confidence that I could then remove the filter. So I gave up, reinstalled the under-shield, and will be taking the car to a dealer that has a magic touch (I hope).

I just finished replacing 8 fuel injector O-rings on our FD, and I thought that was a tough job, but this... no way, lying on my back in a driveway under a jacked-up car. Forget that! :egrin:

Together with removing the rats' nest and changing the differential mounts, this is one of the most frustrating tasks I have done on an FD. I'd rather pull the turbos or the downpipe than do the fuel filter again.

A 20 minutes estimate is wildly implausible for someone doing this the first time. Yes, it is possible - just not likely. It took me two hours the first time and I think closer to an hour the second time. Perhaps if I did it a few more times I might hit the 20 minute mark - but even then some luck would be required.

I think the big trick is getting a good look up in there and knowing where everything is. Removing the aerodynamic pans in the back is a huge help too - you can't see the fuel filter worth a flip with them in the way.

WStrohm, there are 2 bolts that hold the fuel filter bracket to the subframe. Undo the 2 hoses, undo the 2 bolts, drop the whole assembly (bracket and filter) out. Swap the new filter onto the existing bracket, then put it back together.

I do have thin arms, but I've showed others how to do it and they've swapped the filter out themselves without a lot of hassle or time.

Dale

My tiny hands make this job very easy. I think the secret is tiny hands, lol.

Sorry Dale, I had printed out your cookbook steps, bought your recommended tools, and planned to do it your way.

But getting under there and actually seeing where that sucker is, and "not seeing" the mounting nuts, but feeling them with a finger (nuts on studs, not bolts, right?) and trying to visualize how to get at them was very discouraging. Did you have your car on a lift? And it "feels" like the curve of the filter body blocks even a 1/4" drive extension with a 10 mm socket on it from going on the nut(s). I'm paying to have it done, it's beyond me. :(

(~ $112 estimate from H.B. Mazda, if I supply the filter.)

You can access the bolts very easily with an extension through the rear subframe. The "hard" part is getting the hoses off the filter. Its all very easy, really.

This picture shows what I am talking about:

https://www.rx7club.com/attachments/...e-dsc00124.jpg

@TonySeagle,

I cannot relate what I see in your picture to what I see under my car. Can you explain the orientation of the camera? Is the front of car to the right? Is the camera to the rear of the diff case? If so, I could see nothing like this. I was looking up and slightly toward the rear of the car, from the passenger side of the diff. The right-angle turn of the filter's input pipe was horizontal and toward me. Your view in this pic is a mystery to me! I saw no room at all behind the filter! Since I have no visual access to the bracket, and no bracket on the new filter, how is it made? If there are bolts from the back and not nuts on studs going on from the front, then the bracket holes must be threaded, is that right? Then I had the wrong idea of how the thing is mounted.

I found another pic (below) similar to yours. Obviously I got the wrong idea of how the filter is mounted. Thanks for your help!

Just to confirm....did you get it figured out? The pic I posted wasn't mine. I took it from what was posted in the "How-to" portion of this thread. I hope you figured it out because paying $100+ to get this done (especially if you're providing the filter) is robbery.

@TonySeagle,

Yes, thanks, I finally figured it out. I have no filter bracket to look at, and previously had no picture, which means I had to guess at how the filter was mounted. I came to the wrong idea since I had felt the bolt ends at the front of the bracket, and thought they were forward-facing studs. Concluded that there were nuts on those studs that mounted from the front, and that stopped me. My wife has taken pity on me, since I had just finished replacing the FD's 8 fuel injector O-rings due to a fuel leak, which was a multi-day job with interruptions, and she says I don't need to do the filter replacement myself.

Good stuff. Glad you figured it out!

Nice post! The 20 minute part is the one I dont understand. Lol. For me it was more like 35 minutes

Thanks for the write-up! Took me about 35 minutes as well, but I spent a bit of that admiring all of the "speed holes" in the suspension :lol:

Just read through this whole thread. I see a few references to the factory maintenance interval for the filter. Are people moving that up sooner in general or what? My filter was changed 16 months/5k ago. Mazda filter. I also now have a new Walbro FP installed. Will be getting the car street tuned within in the next couple of months in theory. Do I need to go ahead and change the fuel filter again? Or should I be good to go based on when it was last changed? Thanks.

Undoing the bracket bolts is not too bad... As shown in the photos above, you can go through the rear crossmember with a 1/4 drive ratchet and extension.

The thing that caused me to give up and tighten the bolts and walk away was trying in vain to break the seal on the hoses. You can't get up to them by hand and you definitely can't fit a pair of any sort of pliers up there to grab the hoses and twist or anything as its too space restricted. Job's like a 10/10 on the difficulty scale. Why Mazda decided to put that goddamn filter right there is maddeningly crazy.

I've seen recommendations about the fuel filter change every 15k miles

It's simple if you drop the subframe :D

That's exactly what my post outlines - what tools you need to break the seal and reach the fuel filter and get it done.

The hose pliers and WD-40 are key to get the hoses to break their grip on the fuel filter.

Dale

yea i ended up just hose-clamping it to the subframe for easy change next time too

I remember doing mine and it wasn't too bad. I also changed the diff and tranny fluid while I was down there.

I unbolted the filter assembly and that took 2-5 minutes.

It took a little bit getting the fuel hoses off, but putting it back on I was amazed I got the thing together in like 3 minutes, luck, probably.

Thanks for a write-up.:icon_tup: When doing the rear suspension I'll get mine changed. Seems like a good time... under the car. It always helps to have a mechanic of a cousin that has a two post lift to do any work on any car. Surprising that my RX7 fits (coilovers/body kit). Work easy my friends.