Frequently Asked Questions for the FC3S

Here is a list of commonly used abbreviations for the Mazda RX-7. This applies to all generations, but mostly the 2nd generation: AAS = Auto Adjusting suspension
ACV = Air Control Valve
AFM = Air Flow Meter (also see MAF)
A-spec = North American Spec
ATF = Automatic transmission fluid
Auto = Automatic transmission
AWS = Accelerated Warm-Up System
BAC = Bypass Air Control
CAS = Crank Angle Sensor
CPU = Central Processing Unit (the Body computer)
DEI = Dynamic Effect Intake (found on 84 and later 13B engines)
DMM = Digital Multi-Meter (required for most electrical testing on cars)
DTSS = Dynamic tracking suspension system (found on all 2nd gen RX-7s)
ECU = Emissions Control Unit (also called Engine Control unit)
EFI = Electronic Fuel Injection
EGI = Electronic Gasoline Injection
EMS = Engine Management System (aftermarket engine computer)
FB = 1st gen RX-7 81-85 production
FC = 2nd gen RX-7 86-92 production
FC3C = 2nd gen RX-7 convertible
FC3S = 2nd gen RX-7 Coupe
FCD = Fuel Cut defender (aftermarket- used only on Turbos with modified exhaust and stock ECU)
FD = 3rd gen RX-7
FI = Fuel Injection
FMIC = Front Mount Intercooler
GS = Sporty Model (in CAN)
GT = Sporty Model with Turbo
GT Limited = fully loaded every option turbo model.
GTU = Sporty model in 88, base model in 89-90 (in USA)
GTUs = Sporty model in 89-90 (in USA)
GX = Luxury Coupe model (in CAN)
GXL = Top line Luxury non turbo model
J-Spec = Japanese/NZ/AUS spec model
LSD = Limited Slip Differential (sometimes incorrectly called Posi or Positraction which is GM’s in-house brand name for their Limited Slip Differential)
MAF = Mass Air Flow sensor
MOP = Metering Oil Pump. Oil Metering Pump as called in the service manual. (also see OMP)
NA = 1st gen Miata
NA = Normally aspirated/ Non turbo
N/A = Normally aspirated/ Non turbo
NB = 2nd gen Miata
OE = Original Equipment
OEM = Original Equipment Manufacture
OMP = Oil Metering pump
PD = Pulsation Dampener
PS = Power steering
PW = Power windows
SA = 1st gen RX-7 79-80 production
Savanna = The name the 1st and 2nd gen RX-7 was sold under in Japan.
SE = Base model in the USA in 87.5-88
Series 1 / S1 = 1979-1980 RX-7 models
Series 2 / S2 = 1981-1983 RX-7 models
Series 3 / S3 = 1984-1985 RX-7 models
Series 4 / S4 = 1986-1988 RX-7 models
Series 5 / S5 = 1989-1992 RX-7 models
Series 6 / S6 = 1992-1995 RX-7 models
Sport = 86-87 Sporty model (in USA also see GS)
TB = Throttle Body
TBM = Throttle body modification
TID = Turbo Intake Duct
TMIC = Top Mount InterCooler (factory style for FC3S) SMIC = Stock Mount InterCooler (factory style)
TPS = Throttle position sensor
TII = Turbo model (does not mean twin turbo)
T2 = Turbo model (does not mean twin turbo)
VDI = Variable Dynamic Intake
WOT = Wide Open Throttle

6PI = 6 Port Induction the auxiliary ports, or the not so correct term – 5th/6th ports
13B = Normally aspirated/ Non turbo, 2 rotor, rotary engine.
13BT = Turbo charged, 2 rotor, rotary engine
13B-RE = J-spec Mazda Cosmo 2 rotor, rotary engine. (1.3L, Sequentiel Twin Turbos)
13B-REW = FD twin turbo, 2 rotor, rotary engine.
20B = J-spec Mazda Cosmo 3 rotor, rotary engine.(2.0L, Sequentiel Twin Turbos)

Engines (engine swaps and the quest for more power).

1- My RX-7 runs ar 3000RPM at startup. Is this normal?

Yes, this is the Accelerator Warm-up System (AWS). Start the RX-7 with the clutch engaged and the car is 1st gear.

2. My RX-7 doesn’t start!

Remember, when starting a fuel injected car, you should never pump the gas as this will flow the engine. Keep the gas pressed while you turn over the engine, but don’t pump the pedal. If it doesn’t start after a few tries, remove the EGI fuse (engine bay, driver’s side) and try turning it over couple of times again. Afterwards, reinstall the fuse and try again. If it still doesn’t start, you should try removing and cleaning the spark plugs (or better yet, change them, but cleaning may do the trick.) Then, put a teaspoon of Automatic Transmission Fluid in the lower spark plug holes. Reinstall the spark plugs and try turning it over again. Be sure to change the oil once the car is able to start. Do it the same day to avoid the mess!

3- I just got my RX-7 and I want to make it faster, what modifications should I do first?

Do a full 100,000km tune-up. Replace all fluids (brake, clutch, transmission, motor oil, prestone, differential oil) spark plugs and cables, all filters (fuel, oil, air) straps, all hoses with leaks or lumps, as well as the O2 sensor (Oxygen Sensor). If the vehicle has more than 200,000kms, change the Pulsation Dampner (or Primary Fuel Rail” and “Integrated Pulsation Dampener, in the case of the FC 89-91

4- My RX-7 has a heistation between 3500-4000 RPM when accelerating, is this normal?

The famous 3800RPM hesitation, 90% of the time, is caused by a bad ground between the motor, the battery and the car. Clean or replace all the ground connections in the engine compartment. On 1986 models, replacing the pressure sensor ground has proven helpful. (ONLY ON ’86 MODELS, not applicable to ’87 models) If these is still a problem, change the injectors. On N/A models, be sure the 5th and 6th ports are working properly.

5- My idle is very unstable.

This is likely just your TPD that needs readjusting.

6- I think my engine overheated. How can I check is the coolant seals are good?

Fill up the cooling system completely (while the engine is cold). Be sure that the preston’s is completely filled to the brim. Dont put on the cap. Remove the EG fuse. Turn the engine over (it shouldn’t start). If a large quantity of coolant comes out, it is probably your collant seal that is finished. There will be a smell of gas/exhaust in the coolant.

7- Should I modify the injectors in a N/A RX-7?

Preferable not. The RX-7 N/A fuel system can handle up to 250HP, which you won’t be hitting unless you did a big bridge port or peripheral port. The stock N/A system already runs very rich, so you can get gains by making the mix a little less rich. Installing bigger injectors will only cause you to lose power and burn more fuel.

8- What injectors don RX-7s use?

84-85 13B NA, low square center, 680cc, orange, 195500-0900
86-87 13B NA, low square center, 460cc, red, 195500-1350
86-87 13B Turbo, low square center, 550cc, tan, 195500-1370
88 13B NA, high square offset, 460cc, purple, 195500-1350
88 13B Turbo, high square offset, 550cc, purple, 195500-1370
89-91 13B NA, high oval center, 460cc, red, 195500-2010
89-91 13B Turbo, high oval center, 550cc, purple, 195500-2020

9- What kind of fuel consumption can be expected of an RX-7 (FC3S)? What can I do to increase the number of KM/L?

The RX-7 is a sports car. So fuel consumption is around 15-18MPG city and 23-26 MPG highway. If you do more than this, you either have a heavy foot, or your RX-7 needs a tune-up. To reduce consumption the first thing to do is a FULL tune-up. Change the spark plugs, spark plug cables, fluids, filters, timing, adjust the TPS, and everything else we outlines in the 100,000km tune-up. (also refer to the Haynes Manual). Consider driving with a lighter foot. Accelerate slowly, slow down to stops in neutral instead of in gear, and keep the engine under 3800RPM. Also, consider getting an air-fuel moisture gauge which shows if you’re running too rich or too lean. Believe it or not, a little Patience can often lead to lower fuel consumption.

10- How does the RX-7 (FC3S) drive in the winter? Is it safe?

Contrary to popular belief, if you know how to drive, the FC3S drives like any other RWD in the winter. Good winter tires are a must. Remember that with all RWD cars, you need to go very easy on the accelerator and clutch. If you have any doubts in your abilities, consider winter driving courses.. Be sure that your RX-7 is in very good shape (tune-up recently done). The cold can make small problems catastrophic very quickly, rotary and piston engines alike. If you live in an area that uses salt, be sure to have your car oil treated every year. Aside from this, winter driving can be fun provided you practice safety.. Many Canadians use their RX-7 year-round. In Japan as well, despite their less intense winters than ours.

11- What is the lifespan of a rotary engine? Do I need to rebuild?

Most 13B can go up to 250,000/300,000kms. While most 13B-T can last up to 200,000km. Remember that with proper maintenance, they can ask much longer.

12- Can an FD engine (13B-REW) fit in an FC?

The simple answer is no. The motor mounts are in completely different positions, as well as other differences. But if you have a lot of time and money, anything is possible.

13- Can I install an RX-8 (Renesis) in an FC?

Technically tes, but is definitely not a bolt-on swap. The Renesis uses different motor mounts. The ECU and wiring harness are COMPLETELY different. Anything is possible, but it is much more involved than swapping a 13B-T in an FC. There will be a lot of custom fabrication, wiring and other things to be sure the engine is supported and functional. It is such easier to swap a 20B or a 13BT from the TurboII

14- What is the stock Horsepower of the RX-7?

86-88 NA 146 HP @ 6500 RPM w/ 138 Ft/lb @ 3500 RPM
86-88 Turbo 182 HP @ 6500 RPM w/ 183 Ft/lb @ 3500 RPM
89-91 NA 160 HP @ 7000 RPM w/ 140 Ft/lb @ 4000 RPM
89-91 Turbo  202 HP @ 6500 RPM w/ 196 Ft/lb @ 3500 RPM
Infini IV  215 HP @ 6500 RPM w/ 206 Ft/lb @ 3500 RPM

15- Can I install an S5(89-91) intake in my S4(86-88)?

Yes, but it isn’t bolt-on. Some fabrication and custom wiring will be needed.

16- Where should I install the sensor for my aftermarket temperature gauge?

There is a lot of discussion about where exactly to put the sensor for water-temperature sensors. The best location is on the housing of the water pump, close to the ECT sensor (Engine Coolant Temperature). Tap and die the threads on the sensor (usually 1/8”) It is important to install the sensor before the thermostat.

17- How do I remove the flywheel and flywheel nut?

The flywheel nut is torqued to approximately 350lb/ft and the dimensions are 54mm or 2-1/8”. You’ll need a breaker bar or impact gun and a way to see the flywheel stable while you undo the flywheel nut. The flywheel can then be removed.

Body & Wheels

1- Can I install RX-7 89-91 (S5) taillights on a RX-7 86-88 (S4)?

Yes, with some modifications to the RX-7 86-88 (S4) chassis.

2- Can the bumpers and moldings of the RX7 89-91 (S5), fit on the RX7 86-88 (S4) ?

Aside from some fitting holes on the front bumper, the moldings and bumpers should fit quite well.

3- Will the 3rd gen (FD) mags fit on a 2nd gen (FC)?

If you are 5-bolt already and using spacers. Normally you will need +/- 25mm (1”) spacers depending on what size tire you’re using.

4- What do the VIN numbers mean?

For North American vehicles, here is the breakdown:

RX-7 86-88 (8/85 – 12/88)
JM1 FC 33 1 * G 0 ######
JM1= Mazda Passenger Car
FC = RX7 Series
33= Coupe
35= Convertible
1= 1308cc 13B rotary non-turbo
2= 1308cc 13B rotary turbo
*= Check Digit
G= 1986
H= 1987
J= 1988
0= Hiroshima Plant
######= Serial Number

RX-7 89-91 (12/88 – 7/91)
JM1 FC 331 * K 0 ######
JM1 = Mazda Passenger Car
FC = RX7 Coupe
33 = Coupe
35 = Convertible
1 = 1308cc rotary non-turbo
2 = 1308cc rotary turbo
331 = Coupe w/auto shoulder belt
332 = Coupe Turbo w/auto shoulder belt
333 = Coupe w/o auto shoulder belt
334 = Coupe turbo w/o auto shoulder belt
351 = Convertible w/o airbag
352 = Convertible w/ airbag
* = Check Digit
K = 1989
L = 1990
M = 1991
0 = Hiroshima Plant
###### = Serial number

Build dates by serial number:
Model year—–Production Date—-Serial Number
1986————–8/85 – 6/86——100001-200000
1987————–6/86 – 7/87——500001-600000
1988————-7/87 – 12/88—–600001-700000
1989————12/88 – 12/89—–700001-800000
1990————12/89 – 11-90—–800001-900000
1991————–8/90 – 7/91——900001-950000

Electrical (including radio wiring and audio as well as warnings/beeps)

1- My wipers work at a very slow speed.

The wiper switch has a relay inside that is probably defective. So it will have to be replaced.

2- My taillights don’t work but my headlights do.

The connection to the light switch is probably burnt. Look behind the light switch.

3- My dashboard lights don’t work.

Be sure that it isn’t just the dimmer that needs adjusting. If this isn’t the problem, the connection may be burnt. Check behind the light switch.

4- All of my warning lights are on.

This is normal (like with most cars) when the key is set to ON but the car hasn’t yet been started. They should all go out once the car is on. While the motor is running, the alternator’s “failure warning circuit” makes sure the CPU activates this light when the voltage drops below 12 volts. It is either the alternator, a belt, or a bad connection in the fuse box in the engine bay. The voltage in the car and the voltmeter in the cluster (non-turbo models only) needs to be higher than 12.6 volts. If it is below 12.6 volts, your alternator isn’t producing enough power to keep the car running. You also need to stay at 13.6 volts or higher to charge the battery.

5- What are the wire colours for an aftermarket radio?
LightBlue/Red = 12v+
LightBlue/White = +Accessory
LtBlue/Yellow = -power ant trigger
Red/Black = + Lumination
White = Factory Amp Turn on

You need to ground the chassis. Use a 10mm bolt behind the central console and the access panel on the driver side. DON’T use the Res/Black as this will damage the circuit for the interior lights and dimmer.

Front Speakers (maximum 15 watt peak):
LtGreen/Red = Left
LtGreen/Black = Left

LtGreen = Right
LtGreen/Yellow = Right

Rear Speakers (if you have “amplified speakers” at the rear, a maximum of 15 watts peak is the highest that the stock speaker amp input can handle ):
Brown = Rear Left
Brown/White = Rear Left

LtBlue = Rear Right
LtBlue/Orange = Rear Right

Lubricant & Cooling

1- My RX-7 consumes a lot of oil. How often should I be checking the oil level?

Every time you re-fuel, you should check your oil. The rotary engine was designed to inject a certain amount of oil into the engine depending on the accelerator position. If you have a heavy foot, you’ll consume more. It is normal to consume around one quart every 3000-5000kms

2- What kind of oil should I use?

Click here, we wrote a whole article on oils!

3- How can I stop the buzzer when the coolant gets low?

You need to bleed the coolant system or add missing oil. The buzzer is there to help you NOT blow the engine!

Suspension & Driveline (including transmission)

1- Can I install a TurboII transmission on a N/A?
Yes, but here is what you’ll need:
-TII flywheel, clutch, pressure plate
-TII slave cylinder
-TII starter
-TII driveshaft, differential, axels
-Adapt the wiring.

2- Can I install a 6-speed RX-8 Transmission on my RX-7 (FC3S)?

5th gear on an RX-8 is the same as the 4th gear on an FC transmission. So there is no real advantage to using an RX-8 transmission. The 6th speed on the RX-8 is bigger than the FC’s (.83 vs .71), which will simply give you slightly better fuel economy on the highway. Using a RX-8 transmission would be the equivalent of adding a gear between 2nd and 3rd on an FC.

3- Did my RX-7 come with a Limited Slip Differential?

Only the following models (USA model 2nd gen.) came stock with an LSD:

86-88 GXL
87-91 T2
88 GTU
89-90 GTUs (pas les 89-90 GTU)

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