GSL-SE EFI on a 12A?
 

Did some searching and came up empty handed. Lots of swaps for other things etc but not this:

I have a SE parts car with the EFI setup.

How would a SE EFI work on a 12A?

Yes, I know it wont "bolt on." That's not my concern. I'm still not certain if the FB 13B is 6 port, if it is, I'll adapt the intake and work around it.



I'm wondering if anyone has done this, and what issues they came up with from a tuning standpoint.

I can make it fit. No problem. The parts car has a S5 engine that's dead. My '82 GSL has a nice clean 40k mile Pineapple Stock 12A w/ my exhaust work. I'm tired of carbs, poor milage, chokes, needle/seat problems.

And last weekend when I was up on some mountain roads, I was cornering hard enough, that even though the float levels are dead on, fuel was sloshing out of the carb and I was getting a gnarly fuel smell.




If the Mazda computers are anything like Nissan I should pretty much be able to bolt on and go. Maybe a little rich in open loop? Kick the fuel pressure down a little? A 12A and 13B can't be that much different in stock form as far as fuel consumption.

I want turn key, ready to go, reliable induction. Figure this will iron out alot of kinks for my TII swap in the future, (IE fuel system, basic wiring)


Thanks for any and all input.
-Paul

i thought about doing this back in the 90's, i think it would work really well. actually this intake works really well on a 13B, but on a 12A it should have better top end.

you only need 2 parts, in addition to the stock GSL-SE stuff to install it properly on a 12A. you need to rebuild the 12A with the gsl-se center iron to get the fuel injector bungs. RB sells a lower intake that will work with the GSL-SE upper http://www.racingbeat.com/RX7-1975-1...ake/18111.html.

after you do that, the rest of the GSL-SE injection just goes on like stock. i don't know about the wiring, i'm assuming since most of it is on the engine harness, that you only have to hook up powers, grounds, and the tach/clutch switch/trans sensors. probably like 6-10 wires?

the FB 13B is a 6 port, but it doesn't matter. in my experience a GSL-SE with some air flow mods, exhaust etc, the GSL-SE actually runs on the lean side anyways. this is also where the MPG comes from, if you're cruising down the street the closed loop is just turning the engine on and off....

I guess I should start digging into the parts car for the setup.

I have never touched EFI on a rotary. Lots of experiance on piston engines.

There are a set of injectors that go into the housing itself? Any possible way around this? I don't want to take the 12A apart.

You could weld two injector bungs to the manifold. Cheaper and easier than opening up your 12A.

How do these two get fuel? Will I need to mod for a fuel rail, or is it some kind of hose attachment to the injector?

https://www.rx7club.com/showthread.p...ousing+compare

This guy used an S4 intake and deleted the aux injectors? Is that an option?

Twilightoptics....check out my FS thread....I'm selling just the 12A LIM you need.... Hit me....I'm motivated to sell!

all of the EFI rotaries have the primary injectors in the center housing, and if you use that center housing the stock fuel rail just bolts on. which is why i never did it in the 90's, too much work!

you COULD add injector bungs to the manifold, like DF says, mounting a fuel rail becomes custom.

the FC manifolds are possible, but they have a different bolt pattern between upper and lower, so you can't use the RB lower piece, which means you'd need some custom adaptor somewhere, which again is too much work.

Figure changing manifolds and my Lincoln Tig Welder is pretty easy for me.

What's the point of the FC manifold if it too runs the secondary injectors in the center iron?
Looks like they have 4 injectors up top and two below?


It would be pretty easy to put injector bungs on the intake for me.


Patmac - Sent you a PM.

SE and FC 13B have primary injectors in center iron and FC on up have added secondary injectors in the intake manifold secondary runners.

If it were me, I'd make a thick adapter plate to fit between the block and the LIM. Then put the injectors in the plate. The adapter plate can then be shaped to give you better flow from the LIM into the block. Otherwise, you're going to be doing a whole lot of grinding and filling. You probably will be anyway, though.

Actually, if I were going to do a fuel-injected 12A, I'd add some injectors to the stock 12A intake (probably feeding into the primary runners from the passenger side, where the ACV used to be), and use the Nikki as the throttle body. Then I'd control the whole thing with a MegaSquirt in MAPdot mode: no need for a TPS, just a vacuum line and an IAT sensor. If you wanted to, you could even keep the fast-idle part of the choke mechanism to function in the place of an IAC valve for cold starts. Bonus: then you'd have a fully functional standalone for when you do your TII swap.

Never had alot of luck with megasquirt. The software is too convoluted and I haven't had anyone knowledgable that can get me up to speed on it. FAST, Holley, ECMLink, Nistune all pretty easy to get a handle on if you know what the sensors do.




This is going to happen. Time to pull the wiring schematic and have a look see. I'm reading that the SE computer only controls fuel?

Anyone know if the dizzy has a different curve to it?

Correct, the ECU is fuel-only.

And yes, the dizzy is a bit different. As I understand it, it has both a faster advance curve and more total advance.

Easy enough.


I think I'll try getting the whole setup running on the unknown motor, on the engine stand. Just to verify all sensors and ecm works before swapping out my stuff.

yep. its not really enough different that its worth changing distributors for though

Even in the epic quest for MPG? :O)

Exactly what I was thinking.


-billy

So with this 12a RB manifold I've got coming... Just copy the gasket into 1/2" aluminum plate and drill a couple stepped injector holes in the middle. Should be easy enough. Might even be able to utilize the fuel rail mounting....

the distributor curves aren't that different and they aren't that great. you'd be better off re-curving your stock one

There's so little to the wiring on the SE EFI. It's rediculous. I guess I'm used to Datalinks and 8 computers at any given time LOL.

So, how easy, if at all, will the intake STUDS come out? IIRC there are studs in addition to the bolts. Clearly those will need to be elongated.

Pictures coming shortly.

I'm very interested in this as well. Can't wait for the final result.

So I'm currently searching, but figured I'd post here for information under this heading.

So I pulled the engine from the parts car and got a closer look at it.

My concern now..... the omp stuff. I'm so used to 12A and carb... this thing has 2 oil lines going to the rotor housings, and 2 going to the intake manifold passages. There are vacuum lines going to the fittings.

How do these work? Can I put the 2 from the rotor housings to into my custom plate? Or can I just use the 2 from the 12A OMP and run them to the intake manifold fittings and call it good?

I really don't want to run pre-mix.


And this is a bit of a bastardized setup I pulled out. Previous owner deleted the ACV and swapped in a S5 13B. The GSL-SE 13B only has 2 injectors total on this setup... Is that correct?

Thanks guys
-P

Just tee the lines together and run them both into the intake manifold.

Yes, only two injectors on the GSL-SE engine.

adapter plates to readily convert the 12a to use s4 or s5 turbo inlets are readily avail in aus
( tweakit etc )
for ex carbed blocks , the norm is to add injector bungs to the adapter
if you use the mazda injectors then then you can select a type of weld on injector bung that holds the injectors down with a clamp on a rubber sitting around the belly notch
( the injectors fed from hose tails from an external FPR )

else you need to be creative with the injector rail

http://img843.imageshack.us/img843/3429/pic0602886.jpg

Excellent about the OMP lines.

Do I Tee the vacuum section of the lines as well? Or just the oiling lines.



I guess my next question about it, can I use the stock 12A OMP with the two lines and just run them to the intake fittings?

If not:
Will the SE OMP bolt to the 12A Cover? Or do I actually need to swap covers/oil pan to use the SE OMP.

Thanks!!!!!

I haven't directly dealt with a GSL-SE engine, so I'm not positive how the lines are routed. However, if it's like the later engines, those lines don't see vacuum at all. They just connect to a filtered air source. I guess they act like atomizers for the oil or something. Just cap off the ones for the rotor housings and you're good to go.

Edit: scratch that, 12A and GSL-SE OMPs aren't interchangeable.

If you use a 12A OMP with rotor housing oil injectors, it will leak every time. Use a GSL-SE front cover if you insist on using an OMP.

To answer your question, a 12A OMP will not fit a GSL-SE front cover. The bolt pattern is different.

What leaks about them?

Two of the lines on this motor go to the rotor housings, the other two go to the intake.

the nikki carb uses the nylon lines with a rubber slip on hose at either end
the GSL-SE uses banjo's at each end

if you use the oil injectors on the GSL-SE inlet manifold you have to make some sort of hybrid hose
- banjo at the manifold and slip on at the 12a OMP


if you use the GSL-SE OMP you have 4 lines,, 2 that fit AOK
but no position on the housings to use the others
so you install blind bolts instead of two of the banjo bolts at the OMP

unless you are tricky
http://img202.imageshack.us/img202/1412/pic0904522.jpg
12a timing cover modded for the 12at/GSL-SE/s4 FC type 4 way omp units

So drill and tap a hole? That's easy.

I don't see why I couldn't mod the 12A lines to use the banjos, and run into the intake. I have to go look again, did the two banjos on the intake go into the primary runners? Would make sense, since cruise/idle wouldn't have vacuum to move the oil if it was in there.


The main concern is getting enough oil to the engine. Clearly the 12A OMP does it's job. I wonder if the banjos with the filtered air line help regulate it since the 12A stuff isn't under vacuum, but the SE stuff is.

pretty much,, think of them as emulsion tubes with air jet at top, main ( fuel ) jet in the bottom and the side of the tube is venturi fed with oil and not fuel

the oil squirts also have a one way valve function inbuilt to prevent oil continuing to flow post shut down

for the 12a timing cover to 4 way OMP mod you also have to notch that oil feed gallery to match up with the OMP inlet ( as well as tapping the bolt hole )

So why go through the extra effort of modding for the 4 line OMP on a 12A, if you've got a 12A one you can adapt to the banjos, and only need the 2 in the intake?

because IT WILL LEAK

go ahead and make spaghetti joined bitsa OMP hoses
find out for yourself what we are trying to tell you



i have done it both ways,, sometimes you do what you have to do with parts at hand
the bitsa combo does and will fail or leak

but you have all the parts so as to be using complete lines
but you choose to make bodgy joined up ones?


when the oil is hot and your pushed on rubber boots down at the OMP end will do what ?>

I apologize. Didn't mean to offend man. Just trying to understand. This is all new to me. Apparently there are different pressures with the EFI line setup than with the carb setup which just has lines that push on with rubber.

If I need to convert to the GSL-SE 4 line OMP and block off two of the lines with dummy bolts then that's what I'll do. As long as the engine will live: :O)

any updates on this?

Got the parts motor out and working on the harness. I'm going to make it run on the engine stand before starting into my car.

It looks like a FC throttle body? Doesn't look like the lower half is FC though.

And the guy capped off all kinds of lines and such and even the 5-6ports.

Looks like the engine wiring harness should be pretty easy to install.

I'm working on IDing all the components and if they are there or deleted LOL. Obviously the ACV has been removed. As soon as I get the rest of the wiring harness out I'll be able to cut out the lighting portion of the ignition circuit for bench running, and be able to ID the wiring that goes to the dash on the inside of the car, from the ECU.

Component list based on the FSM Wiring Diagram:
-Clutch Switch B-02 (for cruise, '82 12A already has)
-Control Unit B-03 (Heat Hazard Sensor B-04/Light/Reflief Sol Valve B-08)
-Neutral Switch B-05 (in Trans, my trans doesn't have and there is no detent slot in the shifter rail)
-Water Temp Switch B-06
-Switching Solenoid Valves B-09/B-10 VC SOL
-Switching Solenoid Valves B-11 PRC SOL/B-12 VSV
-Setting Connector B-13
-Vacuum Pressure sensor B-14
-TPS B-15
-Air Temp Sensor B-16
-Water Temp Sensor B-17
-Variable Resistor B-19
-Vacuum Switch B-18 (Think it goes to the the sub sero canister?
-Fail Check Connector B-20
-O2 Sensor Check Connector B-23
-O2 Sensor B-24
-Short Connector Fuel Pump B-25
-Air Flow Meter (MAF) B-26
-Injectors B-30/B-31
-Main Relays B-33
-Circuit Opening Relay B-29 (For fuel pump and MAF)
-Ignition coils/ignitors are on the other harness but trailing Negative goes to the tach and ECM Pin U

----What I need to know, is what the switching solenoid valves do and if they are necessary? It looks like they run the vacuum junk under the hood, but I don't see anything on the Hood really or the schematic that makes them affect the engine when the ACV has been removed.

----This Trottle Body seems to have a large Idle Air Control IAC motor on the back and I see no provision for it on the wiring schematic.

---What does the ECM need the netural switch input for? What changes from neutral to not in the algorithim? What happens when I wire it to be in gear at all times?

---What's the point of the Water Temp Switch B-06..... when there is a temp sensor B-17?

---The "Control Unit" not the ECM, has a speed switch inside it. It is connected to the Heat Hazard Sensor and subsequently the warning light, and the Relief Solenoid Valve .What's the RSV do?



Pictures next of the nasty pile I'm working with.

Pics of engine out.

Keep in mind, ALL I unplugged from the engine was the Alternator/Ignition harness. All the other connectors here have nothing attached. I think they are for the switching solenoid valves.

Supposidly this thing ran, just badly. The large vacuum line that's capped off with the cracked falling off cap could be that culprit.....

Well discovered it's not just a FC throttlebody. It's the whole works. So the LIM I just bought wont work at all with the upper half.

I think I'm going to sell off the computer/wiring. Since I have spots for injectors in the secondary runners, I think I'll get a set of TII injectors, build a LIM and run megasquirt. Like stated before, then when I do put a TII in, I'll be golden. MS3X looks pretty easy and Rotary friendly.