Hey everybody.
I have an 86 Series 4 13B NA GLX I've been restoring for a while now.
O.K. Take a minute and then quit laughing. This is serious.
No kidding I really do want to get all this stuff back (correctly) to square one because that's the premise I started with. You know principles and all that crap.

1. Need to know about a nipple located on the top of the keg between the two housing oil metering injectors. Does it go to the fuel injector air bleeds? Should it be capped, left open, or does it attach to a line leading from it to where???

2. Need to know about two nipples located between the fuel injectors on the intake manifold. Do they go to the air bleeds? Should they be capped, left open, or do they attach to a line leading from them to where???

3. On all the '86 NA diagrams a line on the front top of the dynamic chamber near the throttle body (the middle one of three) leads to somewhere around the sub-zero starting system on the passenger side of the engine. Then it disappears. I need to know where that end attaches.

I really would like to start with everything in place like it was when new. Any detailed help about either or all of these points would be of great help to me. Thanks in advance. Foyal Carter AKA fcrx7man.

 

I recall a check valve being in that area, though I don't recall if it attached to the block there or not. I suggest you get a workshop manual, figured you'd have one by now if you're doing a restoration on it.

have a look here Free Download Workshop Manual Mazda RX7 1986 – 1988 | Free Online Auto Repair Manuals Download

 

The only check valve even near that area is connected to the solenoid rack from both ends. The other (plastic) check valve (delay valve) is in the vacuum line that goes from the double throttle diaphragm to the thermo wax behind the throttle body.
I have the Chilton Manual, The Haynes Manual, All the FSM's, and the Factory Wiring Diagrams Book, and even the owners manual. But these three vacuum/supply nipples aren't shown in any diagram or mentioned anywhere as far as I can tell.. My only clue is that in the FSM it says that the Air Bleeds are for supplying fresh air for the Fuel Injectors. Now, the only way air can even get to those air bleeds is through an iron or a housing somehow. These ports are the closest openings I can find to the Air Bleeds and appear to be connected directly to a needle sized hole between the o-rings of the Air Bleed, but if there is a hose connecting these for supply air, where does it originate? And do all three connect with Tees to the same place? In other words do all four of these ports connect to each other?

 

Can you take a pic of the location? Oh - you may be able to find a junkyard with this engine to see how it's routed... if noone else responds here with a 2nd gen they can look at to help you out.

 

Hey Guys, Thanks very much for your help. I know it's a frustrating question because I have sought the answer for nearly two years. It happens that, luckily, ater DJS2571's post, I began to search anew with the question worded a little differently. I searched for information on Air Bleeds specifically and I actually found the answer in another post which follows. Again, thanks to everyone.

Maybe this will help someone else. It seems there are other issues with emmisions removal to be considered. Gladly I already had the others worked out.

Here is the link and the text of the post:

Mazda RX-7: S5 UIM on S4 Engine Block: Vacuum and Fuel Routing

S5 UIM on S4 Engine Block: Vacuum and Fuel Routing
- originally authored by [stevej88na], view article [contributors] -


When adapting the S5 Upper Intake Manifold (UIM) to the S4 engine block, people often remove emissions equipment. One reason is the EGR valve is in the way of the S5 UIM. Traditionally, tuners go "bare block" by removing all emissions and their associated solenoids, vacuum rack, and vacuum hoses. Certain vacuum lines are still required for proper engine operation, however. Not all are true vacuum, but they use the same hoses. Also, when the vacuum rack is removed, the metal fuel lines go with it. This how-to also covers re-routing the fuel lines and BACV. The needed lines follow:

1. Fuel Pressure Regulator (FPR): vacuum
2. Pressure (Boost) Sensor: vacuum
3. Fuel injector air bleeds: metered air in front of butterfly valves
4. Oil injector air bleeds: metered air in front of butterfly valves
5. BACV: metered air in front of butterfly valves
6. Fuel lines: fuel

Note: all other vacuum ports should be capped







Fuel Pressure Regulator


The FPR is located on the secondary fuel rail. It's vacuum port connects to the vacuum port pointing towards the driver's side on the dynamic chamber (DC) near where the DC meets the UIM.



Pressure Sensor


The pressure sensor, a black box located near the passenger-side shock/strut tower, connects to the port angled towards the passenger-front of the car located on the UIM where the UIM meets the LIM. There is a "pill" in this vacuum line that you need to transfer into your new line if you replace it with a new one.



Fuel Injector Air Bleeds


Each secondary injector has its own air bleed, and the primary injectors share a single air bleed. All three need to be T'd to the top of three vacuum ports on the S5 dynamic chamber. That top port leads through the central hole in the black plastic spacer between dynamic chamber and throttle body. The In the throttle body, the route finally exits through a tiny hole just in front of the bottom butterfly valve.



Oil Injector Air Bleeds


The four oil injector air bleeds are near the primary fuel injectors. The four leads combine into one larger lead in the vacuum spider. The four-into-one disc should be kept because it is a valve which keeps oil from leaking when the engine is off. The single large hose off of the spider needs to be replaced with new hose, because the stock port on the S4 throttle body is not on the S5. Instead, the new hose should route to the air funnel. There should be a capped black tube that is the perfect size already on the primary air tube to use.



BACV


Some leave the Bypass Air Control Valve (BACV) off, but as the [Idle System Overview] suggests, removing the BACV will mean introducing idle problems. The BACV needs metered air in front of the TB, and because the S5 BACV is on the passenger-side UIM, while in the S4 it was on the driver-side dynamic chamber, some re-routing needs to happen; the large metal tube off the bottom of the air funnel is ideal.



Fuel Lines


New fuel injection hose is needed. One line runs from the fuel filter to the side of the primary fuel rail facing forward (the side with the pulsation damper). The other end of the primary fuel rail needs to connect to the rear-facing end of the secondary fuel rail (the end without the pressure regulator). Finally, the end of the secondary fuel rail facing forward needs to connect to the fuel return, sticking through the firewall on the driver's side.

Note: The primary fuel rail is below the UIM on the engine block, while the secondary fuel rail is on top of the UIM.



See Also...

• [S5 UIM on S4 Engine Block]
• [S5 UIM on S4 Engine Block: Mechanical Modifications]
• [S5 UIM on S4 Engine Block: VDI Actuation]

 

The only difference in the S4 and S5 intake (as far as the air bleed supply air goes) is that on the S4 the supply air for the air bleed comes from the middle nipple, the top one is for the metering oil injectors, as shown on the manuals (all of them) vacuum diagrams.
Thanks Again,
Foyal