I do love distractions... sure, lets make the RX-7 run!

Well, things were going great with the seat swap, and I was very happy with the level of improvement. 

But then I sat in the seat... Which I hadn't done first, for some reason? Anyway, I noticed my head was way closer to the roof than before. 

Not uncomfortably so, but there is no room for a helmet, and I'm only 5'9"

I had read about these foam-ectomys so I thought I'd give it a go. 

Seat came apart pretty easily. 

And so did the upholstery, I took out a conservative amount and bolted everything back together. 

All back together and you can see the 2" chunk I cut out on the windshield.

I didn't bother with the 4th mounting tab because the seat belt buckle attaches to the car and not the seat. Also, the seat rests nicely on the rail at the correct height. Also, It was different from the others and would have been a pain to engineer, so, laziness. 

All in all , the foam cutting didn't seem to drop me much lower but if I give the seat some gangster lean, you're back around stock height.     

 I also had a brilliant idea to solve the door handle problem. 

I'll just delete them!

Unfortunately, After futzing with these for about an hour, I found out that they are too weak to properly pull the door handle. They are only made to lock and unlock doors and honestly, they were too weak to do that well either. 

So I went back to the drawing board about making some handles....

I am trying to figure out an easy way to make a concave bowl shape out of sturdy enough sheet metal that will also have a nice finish to it. And I am coming up empty here...

Does anyone out there have a broken one I can start with? I think I can make the handle/ lever/ attachment but the backing plate is gonna be tough.

Finally got back around to working on B-Rex. First thing to do was finish the passenger seat. 

I decided to do this side differently, mostly because the passenger foot well is different and the left slider has a weird placement and lean to it. 

So, I started by removing the stock Mazda sliders and installing them in the car. 

Apparently I skipped a few steps on the camera roll, but I cut the new seats sliders off and left the basics of the bracket behind.

Here is the left side bracket, finished and attached to the stock slider. 

Here is the right side, I had to add a spacer since the left side is actually up, on top of the transmission tunnel a bit. 

And since I had to do that, foam-extomy was a necessity. 

All in all, not bad for basically free.

Next up, I've get my sights set on this guy, who I'd wager to say, has an oil leak. 

This is like the fourth rotary related build I have seen tonight. I think the universe is telling me something... :D

Those seats are from a 3rd gen Prelude, '90-'91 specifically for that cloth pattern.

Run_Away said:

Those seats are from a 3rd gen Prelude, '90-'91 specifically for that cloth pattern.

It would appear you are correct! good to know. 

Over the past two days, I've been working on replacing the transmission. 

Step one went smoothly enough, unbolt everything then pulled the busted unit out onto a stack of blocks. 

From here, I needed to raise the car up but was worried the transmission would fall. So I did what any logical father would do, I asked my 3 1/2 year old to operate the lift. He made it go in the right direction and didn't even bash the car into the ceiling. Apprenticeship; day one was a success. 

I had already bought a new clutch, pressure plate and throw-out bearing, but didn't need to, apparently. Looks like everything was replaced right before I bought the car. This was likely an attempt to fix the transmission since the noise it was making, could have sounded like a bad throw-out bearing. 

Nice fresh, pink grease on the input shaft.

Well, since I did take the clutch out, I put the new one in. However, I didn't get a centering tool with the shipment...

Now, where am I going to get a clutch centering tool... (hint, see above photo)

In what was surely a supreme waste of time, I blew the whole transmission apart. 

Although, getting the input shaft off of this one was, more likely an excuse versus a reason. If I've never taken one apart before, then I'll find a reason to take one apart. 

There she is, and if this transmission wasn't that broken before, it sure is now. 

But hey, it works. 

Next issue, the good (I sure hope) transmission had a striped bolt hole for the starter. It was a 10mx1.5 which is easy enough to get a helicoil for, so I bought a whole kit.

It ended up not working perfectly because of how screwed up the threads were in there, but, fingers crossed, I got it.

I friend of mine stopped by on Tuesday and I said, hey, come help me throw this transmission up there, no problem. 

Well, after three tries we still didn't get it lined up right and he had to get going. Which is for the best really because in my haste, I had forgotten to put the throw-out bearing in. 

But when I got back to it this morning, I had no help. At least, none over 4 feet tall. So I made this instead. 

I had already made the top section to fit onto my floor jack so I just welded some plate to it and drilled holes. 

I'm not sure it works any better than the floor jack model, but I didn't have to lay on my back to do the job. So, shrug?

It still took me three more attempts to get it together but I'll call this a moderate success. Could be a useful tool for installing other parts like exhaust and axles as well so, time will tell. 

Still more to button up but hopefully next week, this thing will be street ready!

Getting the transmission to line up with the engine in the car has always been a battle. The only time I've had the marriage go smoothly is with engine and transmission on the bench.

 

In reply to BirgerBuilder :

That is a cool idea. Maybe figure out a limited wiggle or angle for it and it might be easier to "marry" them. Maybe some kind of coil spring, then it could wiggle but still it holds the weight for you. I can pretty much bet this wont be the last transmission you work on.....

Bent-Valve said:

In reply to BirgerBuilder :

That is a cool idea. Maybe figure out a limited wiggle or angle for it and it might be easier to "marry" them. Maybe some kind of coil spring, then it could wiggle but still it holds the weight for you. I can pretty much bet this wont be the last transmission you work on.....

I did leave the bracket attached with only one bolt for that reason. You can kind of shim it how you want. but it does need a little more R&D. 

I started putting all the other bits back in last Friday, like the new master and slave for the clutch but I couldn't bring myself to put the old exhaust back in how it was. 

The header flange for example, was only welded on the outside. and there were holes in it. 

This beautiful patch job...(which may have  been done by me, 8 years ago with very little welding practice)

And, you can tell from that patched up scrape, that the whole system was hanging down way too low. 

So, first I cut off the flange and re-welded it. 

This fixed the angle a bit but I also needed to cut and bend the pipes. 

Here, you can see the resonator and pre-cat are actually above the frame rails now. And the use of my "transmission jack" to help with the exhaust placement. 

It was after this, that I noticed that the stud/flange on the cat was broken, along with everything else. 

I don't think that's right...

So I ordered a new $40 cat and waited till Sunday. I didn't think to order flanges or gaskets though so I went to the bigbox parts stores that are open on Sunday and only came back with gaskets...

Well, I know where I can get a flange.

This took a stupid long time, to cut, drill out old studs, clean up and sand down all the rust off both ends... but I saved $12...

Anyway... decent results. 

Got it all installed before Game of Thrones started. 

I fired it up this morning, and, it leaks. But, only from everything behind the cat. That's ok, I'll dig into that later but I may try and find a better muffler first. Pretty sure it is only using one half of the stock mufflers... 

And as far as I can tell, the clutch, transmission and all other parts are working great. with any luck, tomorrow will be a real test drive!

Cue the Matt Foley video.... "You may find, as you go out there..."

...that a non Rotary /universal Cat on a Mazda 12A or 13B is murder loud. Seems the rotary exhaust gases come out a lot hotter than the typical piston engine and that heavy OEM Cat also has some sound dampening function.

....ex 1981 GSL owner here...

In reply to Agent98 :

With the stock muffler on there, it still seems pretty quiet. (even with some leaks) Hopefully the super hot rotary gasses won't melt the bugger.

Well, I spent all day at the MVA today. I had to make two trips because after waiting in line for 20 minutes they informed me that I needed a bill of sale, since I had bought it at a dealership. So I went home and found this, very old, bill of sale. 

Yup 2008, back when there were Saturn dealerships. but, second trip, success!

Got to drive it on the street and it feels pretty good!

Two problems though, 5th gear seems to have no syncros... like at all. How does that happen?!?

And more pressing, the engine stops making power at 4k RPM.  Before that, it feels fine, after that it either does nothing or bucks back and forth like crazy.

The RX-7 forums say it could be a grounding problem. I thought this was great news since I had forgotten about the ground wire on the transmission. I cleaned and installed it and cleaned up the battery ground for good measure, no change.

I still need to check the ECU ground which is thoroughly buried under the intake manifold but do you guys have any other suggestions of what to look for?  

Check all the grounds, does it free rev past 4k? 

Professor_Brap said:

Check all the grounds, does it free rev past 4k? 

No, above 4k it will rev but only at very light throttle, any pedal input and it falls flat. Grounds have all been checked except for ECU which is very hard to get at. I will likely add a second ground and check for improvement. 

Still trying to track down electrical demons, I added an extra ground wire to the ECU as per the RX-7 forum instructions. 

First, a mouse had to be evicted though. 

And, this super sweet, 90's car-phone was removed. I honestly kind of wish it was complete and I could make it work. No handset though. 

But I ran two extra wires from the ECU to the manifold. 

No improvement though...

New wires front and center, Next things to check are: the secondary injectors and potentially the MAP (boost pressure) sensor?  

Was really hoping it was a simple grounding problem. The search continues... 

Secondary injectors are not supplying fuel is what I'm thinking.

The extra grounds are for a slight stumble at 3800 rpm.  This sounds like your secondary injectors are not firing at all.

This can also be caused by a bad tps.  Check the resistance for the tps.  It should smoothly change from 1k ohms at idle to about 5k ohms at full throttle.  If it has anywhere that drops continuity or jumps around, it's toast.

Your secondary fuel injectors are the easy ones to get to on the passenger side near the top of the engine.  

There is a very important ground under the upper intake manifold.  Have you checked that ground?

wvumtnbkr said:

There is a very important ground under the upper intake manifold.  Have you checked that ground?

The extra ground I installed is meant to assist/ replace that ground, since I couldn't easily get to it. 

Also, I'm quite sure you are right about the injectors not firing. Especially since I just checked them with an Ohm meter and they read 2 instead of the FSM's 12-16. I have an extra set which does read at 12.7 so I will likely try swapping those in. 

When I checked the TPS a few months ago it was working smoothly, I may check it again. 

Well, after some more intensive googleing, (Of mostly 10 year old threads) I found that the injectors should be low Ohms provided they match,(both were right at 2.1) and there is a resister pack under the air box. Check, found and functioning. 

I also decided to check that the 6-port actuators are opening. 

*For those of you who are not familiar with these engines. They have 2 sets of intake runners, 2 short ones that operate during low RPMs and 2 longer ones that operate during high RPMs. The long runners are opened by, you guessed it, the 6-port actuators. 

As I was about to test them out with some vacuum, I found to my surprise, they are not operated by vacuum, they are operated by pressure. Where does that pressure come from? The exhaust! 

Well, it would anyway except, I cut those parts off because I thought they only applied to the EGR system! Doh!

Ok, so first up I need to install the plumbing that goes directly to the actuators. Which is kept under the actuators... 

Only a minor pain, got the line installed. 

After that, I tested with the recommended 2 psi of pressure and...

Next step, weld the  the air tube back to the exhaust.

Drill.

Old parts.

Add aluminum 'gasket' 

And welded up. 

I was super hopeful that this would fix the hesitation issue! too bad it didn't... 

I did see a tiny bit of improvement but it still hits the wall at 3800 and it still doesn't really go past that. 

If you let off and then press the throttle again you will get a tiny burst of speed but it's like a bucking bronco. 

So I'm thinking the injectors aren't firing, I guess I'll make a test light so I can see if they are getting power and go from there... 

You can wire the 6 ports open. You lose some of the already anemic bottom end.

I don't recall seeing information about your mufflers and if you mentioned the exhaust besides that, I've forgotten. 

Try driving it with an open exhaust. It will be LOUD. Wear hearing protection loud. If it goes past 3800 RPM, you've got something clogged. The mufflers can clog if the cats cut loose at any point in time.

Just for shiggles, unplug the tps and see what the car does.

Brett_Murphy said:

You can wire the 6 ports open. You lose some of the already anemic bottom end.

I don't recall seeing information about your mufflers and if you mentioned the exhaust besides that, I've forgotten. 

Try driving it with an open exhaust. It will be LOUD. Wear hearing protection loud. If it goes past 3800 RPM, you've got something clogged. The mufflers can clog if the cats cut loose at any point in time.

I've read that having an open exhaust will not have enough back pressure to open the actuators and cause problems? Also, I'm pretty sure the muffler is not clogged, the cat was not that badly damaged. But I'll break out the endoscope and take a peak. 

wvumtnbkr said:

Just for shiggles, unplug the tps and see what the car does.

Next step. 

Apparently, this is also part of the test to check that the secondaries are working correctly. Too bad I'll be spending the weekend helping my brother rebuild the rear end in our Ram D350. 

I have had many s4 rx7s.  I have never been able to tell the difference between working and not working 6 ports.  I would suggest not spending too much time fiddling with them.

You are basically above 3500 rpm all the time and the ports don't do all that much when closed.  

A vast majority of owners just wire them open and never think another thought about them.