Back from the dead
 

Bringing my old 89 back to life. Just got it running the other day after sitting for about 10 years. I drained the oil, coolant, and gas tank. Flushed the tank the best i could, it was pretty filthy. New fuel pump and filters. New clutch master and slave cylinder. I put some MMO in the motor and let it sit. hand cranked it, let it sit some more. Put new plugs in it and tried to start it. cranked over for quite a while, but actually fired right up. Surprised me. And it seemed to run pretty well, idled fine, revved up good. I put it in gear and it the wheels turned forwards and backwards. I didnt let it run too long as the coolant and oil pressure gauge werent working. I thought i had the pressure gauge hooked up, but must have gotten a bad connection. Coolant sensor has a broken wire coming off of it, i gotta trace the other end of it, wherever it went.
To do;
Brakes- pads, rotors, calipers are probably seized. hard line is leaking too
Drain and fill tranny and rear end
fuel return line is leaking also
check and replace all vacuum lines
headlights wont go down- they turn on and off, just wont go down. ive tried both switches, i can manually crank them down, but after like 3 turns the motor pulls them down and then right back up. so the motors work. Bad switch?
Tires are obviously shot, but thats way down the list.
https://cimg0.ibsrv.net/gimg/www.rx7...2323e93856.jpg
https://cimg4.ibsrv.net/gimg/www.rx7...2d67e7f266.jpg
https://cimg7.ibsrv.net/gimg/www.rx7...f8f105465d.jpg
https://cimg8.ibsrv.net/gimg/www.rx7...f3da168bc4.jpg

Any other suggestions?
She'll never be a show car or a race car. Just hoping to get it back on the road again

Well. . . .Does she run?. . .

Looks awesome!

starts up and runs just fine. Still not road worthy yet though. Working on the brakes.
I got the front calipers rebuilt, trying to get the rears off the car. Bottom bolt on the bracket is about rounded off on both sides. So i try the lower Caliper bolt and can pivot it up, but it wont come off the slide pin. Its so rusted on there. Its soaking in pb blaster until my next attempt. Any other ideas?
Headlights are still bugging me too. Bought a new switch, but they still wont go down, doesnt matter where the switch is. I can pull the fuse and manually lower them, but put the fuse back in, and they both automatically go up. Damn electrical gremlin somewhere.

Making some slow progress. Got all new brakes, rebuilt calipers, new lines ran, the works. Everything seems good, no leaks. Started it up, seems to run ok, exhaust leak and probably a vacuum leak somewhere. Has a slight hesitation. My next question is what are these random wires/plugs?
First is this green and red wire in front of the radiator by the relays. I dont see the other half of it anywhere.https://cimg5.ibsrv.net/gimg/www.rx7...34c73837fb.jpg
Second is this round connector by the TPS
https://cimg2.ibsrv.net/gimg/www.rx7...00250aa50a.jpg
Third is the square white connector by the power steering.
https://cimg0.ibsrv.net/gimg/www.rx7...ca912522b6.jpg

What has worked for me all over my car is using a really good pair of vice grips with curved jaws and sharp teeth and just cranking on it/ ginding two smaller flats on the bolts and using a crescent wrench, or welding a nut on it

-hope that helps :)

well the easy one is the round connector, its for the Aux fan, which a manual trans car doesn't have, it just has the wiring
3rd the white one, goes on an emissions solenoid, i wanna say you don't have those correct, but you should look in the wiring diagrams Foxed.ca - Mazda RX-7 Manuals

and the first one i'm not sure, but the relays are color coded so the green plug will be easy to figure out

Perfect, ill ignore the round fan one. emissions should be all there, I don't see anything that is missing that plug for the white square one. and the green/red wire, I think is the horn. maybe. wiring schematics are like a different language to me.

its not letting me post pics, but the VDI connector is the white one, and the Fog Lights are the green

That Is a running and driving old mazda. Clutch is super mushy. i've bled it a bunch, but the engagement point is almost to the floor. and the pedal likes to stay down a couple inches, like the return spring isnt pulling it back. I think it has enough hydraulic pressure though. maybe i'm bleeding it wrong, or maybe I put the wrong slave or master cylinder on it. because I have replaced them both. hmmmmhttps://cimg3.ibsrv.net/gimg/www.rx7...cacb69f1c7.jpg

So i'm doing more research on this. This is an s4 dynamic chamber, right? Why would that be on my s5? No wonder i could never find where the white plug for the vdi went. It doesnt exist. Am i better off finding an s5 one and swapping everything back? I'm so confused at why the previous owner did this. i know people put s5 intakes on s4s, but why would someone go backwards?
Would it be pretty basic to go back to what should be there?
https://cimg6.ibsrv.net/gimg/www.rx7...ab35644f0e.jpg
https://cimg1.ibsrv.net/gimg/www.rx7...5cd2e5162a.jpg

I have heard that some people do that to try and "make the engine bay cleaner"

dumb. I mean it works, but i'd still rather have the correct part in there.

That's a very strange choice. I've never heard a person express fondness for the S4 manifolds over S5 at all, actually. I think they look a bit nicer but that's just IMO.

Either way it will lose you power not having the VDI system. Also, check how the port actuators are connected to make sure you have aux port functionality.

just when i was getting all excited about getting it back up and running again. More things to the list. Are s4 and s5 lower intakes different too? Maybe the whole deal is s4. oh well, the joys of old cars. Gives me something to research tinker with.

Different are the following:

- Lower intake manifold
- Upper intake manifold / dynamic chamber
- Throttle body.
- Both fuel rails are different between series, although primary are swappable. Not sure about secondary.

Then the emissions stuff is different I think, BAC valve, and port actuators too. Port actuators are exhaust pressure driven on S4, air pump driven on S5. I think S5 has no EGR valve, so you can look under the intake. If one is there, you have an S4 engine (could be wrong about this though).

Now you have a S5 throttle body for certain, since you have two TPS. This implies that maybe someone blew the S5 engine and swapped in the S4, but retained enough electronics to get it to run. They would also need to swap the front cover and OMP to make the ECU happy, or block the OMP off and have the ECU chipped with an Rtek to make it not care if the OMP is there. There is probably other stuff I'm forgetting.

Anyways, it's a weird choice since you could easily just install an S4 shortblock with all S5 accessories, and probably still make more power than a stock S4 due to the VDI system (although not as much as a full S5 engine of course).

EDIT: You know what else is weird? The BAC connector looks like the S4 type. So either they made a patch harness that isn't visible in the picture or they cut the stock harness and swapped connectors. There's a whole lot of weirdness here.

Youre a smart man, Wondrous. It looks I have plenty of investigating/research ahead of me.

https://cimg9.ibsrv.net/gimg/www.rx7...979cf0ccac.jpg
https://cimg9.ibsrv.net/gimg/www.rx7...8d391706e8.jpg
https://cimg0.ibsrv.net/gimg/www.rx7...5c534cf478.jpg
https://cimg6.ibsrv.net/gimg/www.rx7...5af9f4d015.jpg

I'm starting to think that I have a frankenstein car. Is that the egr in there? if so, then its an s4 motor, right? 6 port actuators are the push in type, aren't s5's pull out? aaand they're capped off, so they've never worked. cool. Electric OMP, and maf off an s5. BAC is definitely ghetto wired into the connection. And I think I read somewhere that the thermostat housing is plastic on s5's and metal on s4. Mine is plastic. So i'm thinking Wonderous is right. Someone blew up the s5 motor, stuck the s4 in there with most of the s5 accessories. weird and stupid. I'm not too happy about all that. Its all so confusing, so many random parts here and there. Orrrrrrrrrrr maybe i'm completely wrong about everything

Yeah, that's likely a frankenstein engine. Again this is a really weird choice, since the S4 keg will accept all the S5 accessories and make decent power. Not sure why someone would try and retain the S4 parts.

From what I can see, you have:

- An S4 engine. Technically all we know is that the center iron is S4 because that's where the EGR mounts, but lets assume that the whole engine is since we don't know.

- S4 Intakes as we established, including ACV, BAC, EGR, etc.

- S4 port actuators. Not sure if the S5 ones will bolt to an S4 manifold, but yours look like S4. It's worth noting they are capped off and disconnected in that photo. This makes sense since they come from the exhaust tube on an S4, but your car will have no such tube. Either you need the S4 exhaust parts, a Racing Beat header with the tube, or use a RPM switch, actuator, and tap the air pump for the pressure source to activate them at 4000rpm. There's a write-up for this in the archive I think. Or just get all the S5 manifolds and install those, picking up some power along the way.

- S5 throttle body to retain the sensors to keep the ECU happy.

- Electric OMP (if I'm interpreting that picture correctly) to keep the ECU out of limp mode.

EDIT: Actually it looks like you already have headers, so check and see if they have a barb for the port actuators. That would save you a lot of trouble and restore about 20hp up top.

quick response. I know that I put that exhaust on forever ago, and that's all that I did to the car. And its for an s5(which I assumed it was), so no barb. This was long before I knew a whole lot about this car. yes its electric omp, as far as i can tell anyway. Hard to see in there, plus its covered in gunk. Either way, there's no rod to connect to the throttle body. I'm leaning towards just getting the s5 intake manifolds. I read that there's a little bit of custom grinding involved. Will I need all new s5 acv, and bac as well? and probably the rats nest/solenoids for the vdi?

I don't know about grinding, since I've never tried it. You will almost certainly need to block off the EGR, which is fine since I don't think it will function on an S5 manifold anyways. I believe the S4 BAC will fit on the S5 manifold, and you already have the... "custom"... wiring adapter the previous owner left you. Not sure if the tube points the same way though since the BAC sits on a different part of the manifold. ACV is different I think, rats nest as well, solenoids are just solenoids so they may be swappable. I would try and grab everything at once if at all possible, otherwise you'll be chasing parts for ages.

I would grab both the S4 and S5 factory service manuals (free at Foxed.ca) and compare the images.

I see ebay has manifolds and the rats nest. Not as one sale, but its all from the same seller and all off the same car. I should snag all that up. I already have the s5 service manual downloaded and actually printed out. never woulda thought i'd need the s4 one....

if you have the S$ motor (which is what it looks like) you need to keep the S4 lower intake, as the air injection passages are different. other than that though, pull everything off the top and replace with S5 and you're in good shape!
the S4 and S5 have a different stud, but if you pull that out, you can switch between them

That's a good point, if OP needs to pass emissions then the air passage is different. He still won't be able to fit an EGR valve though, as far as I know.

Here's a weird question I've been thinking about that you may have the answer to J9:

Does the throttle body end up in the same spot when using the S5 upper?

Reason I'm asking is this whole thread has got me thinking about installing an S5 upper on my S4 lower, then wiring the VDI system up with an RPM sensor to gain a few HP. But I like my mechanical OMP, so I would need the throttle body to remain in the same location for the rod to end up in the right place.

its probably not in exactly the same place, but its very close.