4 5 6
codrus
codrus UltraDork
12/10/18 9:20 p.m.

Got it almost all the way done today.  It's actually all bolted back together, but the O-ring on the oil level sensor in the pan looks iffy and needs replacement.  None in stock anywhere, and none of my generics fit, so I'm going to have to wait a few days for one from Mazda.  So for now it'll sit on the lift with no oil in it. :)

A few extra shots, here's the engine support:

And the fresh motor mounts.

 

mr2s2000elise
mr2s2000elise Reader
12/10/18 9:27 p.m.

Beautiful car 

 

but with so low mileage - seems like you had lots of problems. Is that common in the FD world? I mean I would think it’s a British car, if I didn’t know better! 

codrus
codrus UltraDork
12/10/18 9:32 p.m.
mr2s2000elise said:

Beautiful car 

 

but with so low mileage - seems like you had lots of problems. Is that common in the FD world? I mean I would think it’s a British car, if I didn’t know better! 

 

Yes, it's common.  These cars are somewhat infamous for being high maintenance. :)


It's worth noting, though, that the stuff I've done to it is basically driven by:

- old radiator & other cooling system components

- AC leak, probably from a cheap R12->R134 conversion

- worn out clutch at 60K (somewhat common, but also likely related to previous owner)

- multiple oil leaks (common)

- dried out and cracked suspension bushings

- shocks that aren't as fresh as I'd like (60K miles)

 

So this is mostly related to the fact that even though it's only got 62K on it now, it's still over 25 years old.

 

mr2s2000elise
mr2s2000elise Reader
12/10/18 10:24 p.m.

^

I was just comparing it to my 93 and 94 MR2 in the garage, and just went through the maintenance. 94 I have owned since new, 9100 miles. 93 I bought when it was 2 years old and 63K miles. Slightly less maintenance than you :p

 

Then again the FD is one of the best looking of all time, whereas my SW20 aren't lookers to people. I have been a long time Miata owner (all generations), and lived across from the bay from  you for about 9 years with them.   Just didn't realize the FD being a Mazda was that high of  maintenance for a Japanese car. 

However, I get to apprecaite it through your thread and that is good enough for me. Enjoy the car, I am enjoying the thread :)

codrus
codrus UltraDork
12/11/18 12:56 a.m.
mr2s2000elise said:

^

I was just comparing it to my 93 and 94 MR2 in the garage, and just went through the maintenance. 94 I have owned since new, 9100 miles. 93 I bought when it was 2 years old and 63K miles. Slightly less maintenance than you :p

Then again the FD is one of the best looking of all time, whereas my SW20 aren't lookers to people. I have been a long time Miata owner (all generations), and lived across from the bay from  you for about 9 years with them.   Just didn't realize the FD being a Mazda was that high of  maintenance for a Japanese car. 

However, I get to apprecaite it through your thread and that is good enough for me. Enjoy the car, I am enjoying the thread :)

 

While the SW20 isn't quite as sexy as an FD, it's definitely on my list of favorite cars from the 90s as well!

The FD is one of the least reliable Japanese cars made in a very long time.  In addition to the things mentioned so far, it's got a tendency to leak fuel from the pulse damper on the fuel rail (sometimes catching fire), to have fairly short life for the rear suspension bushings & pillowballs (I need to order parts to go through and replace all of them on mine), and for lots of turbo control issues.  The twin sequential turbos are all controlled pneumatically, with 50 or so vacuum lines connection solenoids, actuators, vacuum reservoirs, etc.  Those lines bake under the hood (rotaries make a lot of heat and the turbos & pre-cat keep it all in the engine bay), get old and hard, and then when you put boost pressure on them they start blowing off.  Once you've lost one of them, none of the turbo controls work properly any more, and it can be quite difficult to sort out.  Replacing them all is on my list of preventative maintenance things to do.

Also, the 13B REW rarely goes more than 100K without needing a rebuild, the turbo housings crack, the 5th gear synchro is notoriously fragile, and the body control modules pretty much all die.  It is not a daily driver kind of car. :)

It's super sexy and a blast to drive when it's all working though!

 

mr2s2000elise
mr2s2000elise Reader
12/11/18 1:16 a.m.

^^

Thank you for the information, learned a lot! Given the Japanese aren't known (in general) to make unreliable cars, why was the FD so unreliable? Was it just too complicated for its time? Mazda not have enough budget at that time to do it right?  My 95R Miata is one of my favorites, and bulletproof reliable (albeit not comlicated or sexy like the FD).  Next time I am in the Bay, will have to look you up. 50 vacuum lines?! WOW. 

Agree, it is super sexy. I could stare at it in the garage all day - and given my skills and the care this thing needs - if I owned one, that's all I would be doing.

Keep up the great work

codrus
codrus UltraDork
12/11/18 2:07 a.m.

This is the (infamous) vacuum line diagram for the FD:

 

The complexity is all because of the sequential turbo system.  The idea is to use two identical, relatively small turbos, with only one of them operating at low RPM (to give good response) and both of them at higher RPMs (to give more airflow and power).  Making that actually work involves a bunch of valves to redirect exhaust gasses and compressor outlets, all of those valves are pneumatic, with solenoids to allow the computer to switch them when it wants to.

As for the rest of it, I don't know that there's a single overriding cause.  Mazda did a lot of things to make it light, some of which probably hurt longevity.  The suspension is pretty advanced for its time -- aluminum control arms, multi-link rear with pillowballs in place of many of the bushings.  The combination of the rotary packaging with the twin turbos (heat sinks) and the emissions-required pre-cat (extra heat generator) makes the engine bay get really hot really fast and stay that way.  It's not a car that Mazda made very many of, they only brought about 13,000 of them to the US over 3 years, and the vast majority of those are the first model year ('93 like mine).  It's possible that they ironed some of these issues in later model years that never made it here, but I'm not sure.

The naturally aspirated rotaries on the SA/FB and FC last much longer than the turbo 13B-REWs in the FD.  (the RX-8's RENESIS has its' own issues).  Many people would say that turbos on a rotary are just not a very practical idea.

And yeah, Miatas are much more reliable than FDs.  I've got an NB that I bought new (visible in a few of the photos in this thread) and when it was stock it was also very reliable (it's very much not stock any more).

 

The0retical
The0retical UltraDork
12/11/18 9:45 a.m.
mr2s2000elise said:

^^

Thank you for the information, learned a lot! Given the Japanese aren't known (in general) to make unreliable cars, why was the FD so unreliable? Was it just too complicated for its time? Mazda not have enough budget at that time to do it right?  My 95R Miata is one of my favorites, and bulletproof reliable (albeit not comlicated or sexy like the FD).  Next time I am in the Bay, will have to look you up. 50 vacuum lines?! WOW. 

Agree, it is super sexy. I could stare at it in the garage all day - and given my skills and the care this thing needs - if I owned one, that's all I would be doing.

Keep up the great work

The reliability stuff is mostly a function of the pre OBD2 emissions days and less advanced turbo systems. The automotive world is lightyears from where it was in both those areas. The FD's turbo system, while cool in it's own way much like the Nissan R32 and R33, introduces a lot of failure points because the complex vacuum system. The Japanese bubble cars are really the pinnacle of analog turbo engineering. Modern systems, while requiring a different skillset, are a walk in the park comparatively.

The major reliability item with rotaries, the FD especially, crop up because they don't like to sit or be pampered. The engines like to be run and run hard. FD's in particular are known for the sequential turbo to have issues if you don't drive it hard as the gate will stick if unused.

Most of what you see on the internet with rotaries E36 M3ting their apex seals is from someone getting greedy with the boost (usually with a manual boost controller) or not topping off the oil in during fill-ups. While the 13b can be made to hold a lot of boost you have to be careful because it's an analog application without the granular engine mapping modern ECU's provide. The oil part is just second/third/fourth owners not knowing how to care for the thing.

mr2s2000elise
mr2s2000elise Reader
12/11/18 9:47 a.m.

In reply to The0retical :

In reply to codrus :

 

You guys are awesome! That is why I love this site. Learn something so much more than just "FD are unreliable, apex seals blah blah."  Really appreciate the education, and love this thread! Thanks

AnthonyGS
AnthonyGS Reader
12/11/18 4:10 p.m.

Gorgeous car.  This is one of the few that stays on my want list.  If you ever sell.... 

codrus
codrus UltraDork
12/11/18 6:40 p.m.
mr2s2000elise said:

You guys are awesome! That is why I love this site. Learn something so much more than just "FD are unreliable, apex seals blah blah."  Really appreciate the education, and love this thread! Thanks

 

Yeah, the apex seals usually aren't a problem, unless you let someone turn the boost up without addressing fueling and it detonates.  AIUI, it's usually the side seals that wear out and lose compression. :)

codrus
codrus UltraDork
12/14/18 1:12 a.m.

The O-ring from Mazda arrived today.  I bought two, just in case I screwed one up (they were only $2 each).  Came in a ridiculously large box for two O-rings. :)

Here's the level sender in the pan (it has three bolts, but I'd taken one out before I remembered to take a picture of it)

And from below

The sender looks like this  You can see that the old O-ring has a triangular cross-section now.

New O-ring is round like it should be

With that buttoned up it's time for oil

Woohoo, it has oil pressure!

Took it for a drive -- it definitely likes the colder air out now.  Replacing the motor mounts has made it idle a lot smoother too.

The natural order of things is restored.  :)

 

codrus
codrus UltraDork
12/20/18 3:55 p.m.

Well, the oil stains on the garage floor under the FD don't seem to be getting bigger, so it looks like I had at least some success here. :)

 

Drove the FD to work today.  Found a nice-looking NSX to park next to at lunch.

mr2s2000elise
mr2s2000elise Reader
12/20/18 4:03 p.m.

Now THAT's a machine (NSX), as far as reliability, looks, driveability, and heck even investment!! I remember in 03/04 they were blowing them out with $699 lease specials. Now those cars bringing huge money. 

4cylndrfury
4cylndrfury MegaDork
1/4/19 10:15 a.m.

Love Love Love this thread.

Knowing how heat ravages these cars, any thought to putting that stock hood in a box, and putting a hood with a huge vent on it for driving around? I know you said you dont daily it, but all that heat would worry me constantly.

codrus
codrus UltraDork
2/9/19 6:34 p.m.
4cylndrfury said:

Love Love Love this thread.

Knowing how heat ravages these cars, any thought to putting that stock hood in a box, and putting a hood with a huge vent on it for driving around? I know you said you dont daily it, but all that heat would worry me constantly.

 

I dunno.  I find hood vents really ugly, and I don't want to drive an ugly FD. :)  I did pick up a petit racing downpipe which I haven't gotten around to putting in yet -- that should help to cut down on the engine bay heat.  I'm going to add a wideband bung to it and monitor AFRs -- if they go too lean I'll swap the stock downpipe back in.

 

In other news, a friend of mine needed to clear out some storage and was getting rid of some FD parts, including the motor that had come out of one of his cars (replaced because of low compression, I believe).  I've had thoughts about rebuilding the motor on my FD for a while, so I grabbed it.  It remains to be seen how many of the parts are useful -- the turbos had been sitting outside and had water in them, so I'm sure the bearings in them are trash.  Perhaps they're useful as cores?  I dunno.  The motor itself had been indoors, fortunately, but since the donor motor he was putting in had come out of an automatic, he swiped the rear housing from the old motor, so it's been sitting open for a while.  The price (free) was right, though.

 

The rear rotor had been sitting next to the motor:

New HF engine hoist -- I've borrowed one many times from friends, decided it was time to buy one for myself.

There's a bit of rust on the surface of the eccentric shaft -- hopefully that'll just polish off.

I need to get a rotary engine stand adapter, so right now it's just sitting on a pallet.  Of course, since the adapters bolt to the rear housing, and that housing is missing from this motor, it's not clear how useful it would be...  Yes, it's missing all of the tension bolts -- held together by the oil pan and the exhaust manifold, I guess?

This is the rear housing off the automatic motor.  From what I've read it's actually not that hard to use these with a manual, I'm not sure why they swapped it.

The very rusty turbos.  Probably nothing useful here.

 

codrus
codrus UltraDork
2/28/19 11:21 p.m.

I haven't had a chance to tear the salvage motor down yet, but there are some other things piling up that need doing on the FD and thought I'd post an update.

First, I mentioned I'd pulled the trigger on a downpipe, in an attempt to reduce the underhood heating.  It's from Pettit Racing, and I'll be adding a second O2 sensor bung and installing a wideband to keep tabs on things.  If it looks too lean I'll put the stock downpipe back in.

Second, it looks like the Ohlins have a bit too much travel up front.  A couple times on mountain roads I've felt a front tire rub under compression with a certain amount of steering lock.  Then I noticed this -- it looks like one of those times the tre caught the fender lip and bent it outwards a bit:

My first thought was to take a fender roller to it and see if I could bend it back gently, but I was talked out it.  Instead I'm going to let the body shop guy look at it.  The long-term fix is to add one or two of these to the shock shaft to limit the travel:

(one of those packs is for the Xidas on the Miata, the other is for the FD.  I forget which is which, they're different sizes)

Another item that's come up is the front fender vent.  Often I would go for a drive, come back and notice that the passenger side one had popped out a bit.

I'd pop it back in and go on, and then it would happen again a couple weeks later.  Well, last week it came all the way off.

I've got the vent piece, it didn't actually fall to the ground but was just barely still wedged in place.

The paint on it is fine, but the plastic clips that hold it in are well and truly broken.  Fortunately, Mazda still makes them, so I orderd a replacement.

Obviously it needs paint, so I'll coordinate this and the bent fender with the body guy at the same time.

 

GIRTHQUAKE
GIRTHQUAKE Reader
3/1/19 1:17 a.m.

I can't wait for the hordes of legally-imported RX7s from Japan to start. I think they kept making these until 2001 or so.

BA5
BA5 Reader
3/1/19 7:33 a.m.

These really are amazing cars and yours is super nice looking as well!

To cut down on under hood heat could you use a turbo blanket or something like that to help keep the heat in the exhaust?

And I'd like for us all to take a moment to appreciate that in the middle of that vacuum hose diagram is a single red line marked (in typewriter text) "empty pipe".

docwyte
docwyte UltraDork
3/1/19 7:51 a.m.

I totally would get a fender roller and roll that lip back into place.  Just use a heat gun and get it nice and warm before you start. 

codrus
codrus UltraDork
3/1/19 12:29 p.m.
docwyte said:

I totally would get a fender roller and roll that lip back into place.  Just use a heat gun and get it nice and warm before you start. 

Yeah, that was my first inclination, but I don't think I can get it to the OEM curve with the Eastwood roller that I have.  It's really intended for rolling flat.  It has to go to the body guy for the vent to get painted anyway, so I'll ask his opinion at that point.

The stock turbos on the FD are tucked WAY down, between the motor and the fender, there's really no way to put additional heat shielding on them (there's fair bit of OEM sheet metal shielding).

IIRC, the FDs we got here are "series 6".  Series 7 and 8 cars are all RHD, 7 were sold in places like Australia and NZ, series 8 was only Japan, up through 2002 (I think).  RHD would be a pretty big deal killer to me.

codrus
codrus UberDork
4/14/19 10:43 p.m.

So I tore down the salvage motor today.  I have no idea if any of the parts are useful, and realistically it's probably more expensive to build a motor for it than to just buy a crate engine from Mazda with the MMD discount.  Still, it was fun to take apart -- I've never done that before.  Some photos:

Getting the front eccentric shaft bolt out proved interesting, Mazda loctites these in and it takes a LOT of force to get them off.  The usual recommendation is to use a breaker bar with a cheater pipe on it, but that's kind of tricky with the motor out of the car and not bolted to anything.  To make it even more interesting, this motor was missing the rear housing, meaning that there were no tension bolts going through it, so there wasn't even anything to lock a flywheel to.

 The other approach is to use heat, so that's what I tried.  You need a lot of it.  A couple times I tried heating it for a minute or two, but that wasn't enough.  Finally I gave it 5 minutes of direct flame and then a couple whacks with a sledge and it came out.

Hoist it up, take the oil pan off, mount it on the rotary engine stand adapter.  The ratchet strap is because at this point the only thing holding it together is the exhaust manifold, which isn't attached to the front housing and I didn't want the motor falling apart.

Gotta get the front cover & oil pump drive off so that the eccentric shaft can come out the back.  Doing this upside down was kind of fiddly.

Whee!

Parts on the bench:

The eccentric shaft has a bunch of rust on the back half where it was sitting exposed at the other guy's shop.  I have no idea how to evaluate the chrome on a rotor housing -- there's no obvious missing spots, but a lot of it looks like this:

The three faces on the two irons that came out of the motor have a bunch of discoloration where the combustion was happening.  Anyone know what this is?

(big pics of all the parts here)

4 5 6
Our Preferred Partners
XL0zgDf0WxcQG4b7h9uaYC7oR1v8FrKpZaghy6PFZTauM8kmf3qGoNaXE2VgqLXK