FD RX-7 FAQ/Write up

**REY** · 05-11-2006 11:27 AM

Originally Posted by CrypticApathy

Can you find one for the FC and FD RX7's?

FD general FAQ - obtained from marx7.org

2.1 When were they made?

The manufacture of 3rd Generation RX-7s started in December of 1991. Mazda did not make a 1992 year model RX-7, as the third generation RX-7 would make its debut in mid 1992 as a 1993 model year. Production continues in Japan, but RX-7s are no longer being imported to the US.

2.2 How do I identify a 3rd Gen RX-7?

They have a "Miata on steroids" look to them. All 3rd generation RX-7s have a VIN that starts with "FD".

2.3 What are the common features & technical specs?

Common Features:
All models of the RX-7 come with the same powerplant, a two-rotor wankel engine with sequential twin-turbos. It displaces 1.3 liters (80 CID). Two transmissions are available, a 5-speed manual with overdrive or a 4-speed electronically controlled automatic with overdrive and a lockup torque converter. All 3rd generation RX-7s come with 4-wheel disc brakes and ABS. They all have fully independent double-wishbone coil-spring suspension, power rack-and-pinion steering, and a Torsen torque-sensing limited-slip differential. Air conditioning is standard, as is an alarm.
Engine
Type: 2-rotor inline rotary
Aspiration: Sequential twin turbochargers and an air-to air intercooler
(Twin Hitachi HT12 turbos w/51mm turbine & 57mm compressor)
Displacement: 1308cc (80 Cubic Inches)
Comp. Ratio: 9.0:1
Horsepower: 255 @ 6500 (manual)
255 @ 6200 (automatic)
Torque: 217 ft.-lb. @ 5000
Ignition: Distributorless Electronic
Fuel Injection: Bosch L-Jetronic based Speed density system

Gear Ratios: Manual Automatic
1st gear 3.483 3.027
2nd gear 2.015 1.619
3rd gear 1.391 1.000
4th gear 1.000 0.694
5th gear 0.719 ----
Rear end 4.100 3.909

Mechanical Standard Features:
2-rotor inline rotary engine with sequential twin turbochargers, air-to-air intercooler, and electronic fuel injection
Engine oil cooler
5-speed manual transmission with overdrive
Power Plant Frame (PPF)
Torsen torque-sensing limited-slip differential
Fully independent double-wishbone suspension with rear shock-tower support brace
Rack-and-pinion steering with engine-rpm-sensing variable power assist
Power-assisted 4-wheel ventilated disc brakes with aluminum 4-piston front calipers and ducted backing plates
Anti-lock Brake System (ABS)

Exterior Standard Features
16-inch aluminum alloy wheels
Dual aerodynamic body-color power mirrors
Tinted glass
Retractable halogen headlights
Lightweight aluminum hood
Interior Standard Features
Highback bucket seats with seatback recliners
Sport cloth upholstery
Dual storage compartments behind seats
Power windows and door locks
Remote liftgate and fuel door releases
9000-rpm tachometer with 8000-rpm* redline
180-mph speedometer
Gauges for oil pressure and engine coolant temperature
Leather-wrapped steering wheel, handbrake grip, and transmission shift knob
Cruise-control with steering-wheel-mounted controls (n/a R-1)
Driver's side air bag Supplemental Restraint System (SRS)
Drilled aluminum clutch and brake pedals (manual trans. only)
Anti-theft alarm system
Heater/defroster with 4-speed blower and side-window demisters
Air Conditioning
AM/FM/cassette stereo sound with five speakers and automatic power antenna
* 7000 rpm redline with automatic transmission

2.4 What models were made and how do they differ?

Base models

Comes with all equipment above, and can be ordered with a 4-speed electronically controlled automatic transmission with overdrive. Can also be ordered with leather seating surfaces.

Black Cloth Black Leather Tan Leather Red Leather
Vintage Red X
X X -
Brilliant Black X - X X
Silver Stone Metallic X X - X
Montego Blue Metallic X - X -

Not available in Competition Yellow Mica.

Touring models

This is an option package consisting of:

Leather seating surfaces
Bose Acoustic Wave stereo music system with compact disc player, five speakers and automatic power antenna
High-reflex paint
Sliding sunroof with tilt-up ventilation feature
Halogen fog lights
Rear window wiper/washer
Upgraded sound insulation
Removeable rear cargo area cover
Touring models can be ordered with a 4-speed electronically controlled automatic transmission with overdrive.
Black Cloth Black Leather Tan Leather Red Leather
Vintage Red X X X -
Brilliant Black X - X X
Silver Stone Metallic X X - X
Montego Blue Metallic X - X -

Not available in Competition Yellow Mica. For the 1994 year model, the touring package was renamed "PEG" for popular equipment group.

"R" models

The "R" model is the performance model, and does not have cruise control.

The "R" model's option package consists of:
Rear spoiler and front air dam
Dual engine oil coolers
Dedicated front brake air ducts
Special suspension tuning
Front shock-tower support brace
Z-rated high-performance steel-belted radial tires
Black Cloth Black Leather Tan Leather Red Leather
Vintage Red X - - -
Brilliant Black X - - -
Competition Yellow Mica X - - -

Not available in Silver Stone Metallic or Montego Blue Metallic.

2.5 What can I tell from looking at my VIN?

A typical RX-7 VIN looks like: JM1FD3311P0200001

In order, the fields are as follows:

JM1 World Manufacturer Identifier" for Mazda
FD RX-7 series
33 body style ("33" = coupe)
1 Misc ID field" (1993: "1" = US, "2" = Canada.)
(1994: "3" = manual seat belts, 2 airbags)
(1995: "3" = manual seat belts, 2 airbags)

1 "Check Digit" (used to verify that a VIN is not bogus, calculated for each car)
P Year model code
1993 = "P"
1994 = "R"
1995 = "S"
(Q was not used)

0 assembly plant code ("0" = Hiroshima)
200001 serial number
1993: started with 200001
1994: started with 300001
1995: started with 400001

So, the car in this example would be a 1993 RX-7 coupe to be sold in the US.

2.6 Are they rare, how many were sold?

Here are the numbers of RX-7s sold in the United States through 1995.

Model 1992 1993 1994 1995
Base 763 1245 392 153
R-model 1107 1015 275 182
Touring 2991 2734 1010 648
P.E.G. 0 53 533 416

* P.E.G. = "Popular Equipment Group" (Used to be called "Touring")

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I want to buy a 3rd Gen RX-7. What should I know?

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3.1 Recalls

There have been three recall notices put out on the 3rd Generation RX-7s, two pertaining to engine fires, and one concerning brake booster failure. You will want to make sure that the car in question has had these recalls done. If they have not been performed, you will want to take the car to a Mazda dealership where they will be performed free of charge. If you don't know whether the recalls have been applied to a car, you can call the Mazda Customer Service line at (800) 222-5500 with the vehicle's VIN, and they can tell you.

3.1.1 Coolant recall

The coolant recall involved the replacement of some cooling system parts with stronger/more heat resistant materials and lowering the pressure of the cooling system from 1.3 bar to .9 bar. The parts replaced were the water pump seal, the water level sensor, the upper radiator hose, the filler cap, the filler cap body, the thermostat gasket, the water hose leading to the throttle body, and the water hose leading to the coolant separator tank.

3.1.2 Fuel line recall

The fuel line recall involved replacing the fuel lines under the intake manifold with lines made from a more heat resistant material, and adding a fan control unit that runs the cooling fans if the coolant gets too hot, even if the car is turned off.

3.1.3 Brake recall

The brake recall involves the replacement of a vacuum check valve and hose leading to the brake booster. The original unit may stick whenoily and cold, preventing power assist under braking.

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Common questions

4.1 What is the "exhaust system overheat" light for?

The "exhaust system overheat" light is connected to a temperature sensor inside the car, under the carpeting, by the passenger seat. The location of this sensor is just above the main catalytic converter, and its purpose is to warn of excessive heat being generated by the converter. When the temperature of the passenger floor reaches about 220 degrees F, the ECU activates the relief air bypass and bleeds off air that would otherwise go to the catalytic converter. This has the effect of cooling the catalytic converter.

4.2 When I start my car, the RPMs go to 3000. Why?

All 1993+ RX-7s have what is called an "Accelerated Warmup System" that revs the car up to ~3000 RPM when it is cold-started. Its purpose is to heat up the 02 sensor and first catalytic converter to operating temperature as soon as possible. If you don't like the thought of your motor revving that high when cold, you can start the car in 1st gear (with the clutch in), and the AWS will only take the RPMs to ~1500 or so.It is also possible to bypass the AWS solenoid (see the performance section of this FAQ).

4.3 What does the "mileage switch" do?

The "mileage switch" is in effect for the first 20k miles on a new RX-7. It has the same effect as the "power steering switch". It adds some RPM to the base idle to help keep the engine from dying.

4.4 What type of gas should I use?

The RX-7 requires "super" or "premium" unleaded gasoline. Use only gas with a 92 or higher octane rating. Using leaded gas will coatboth your catalytic converters and your oxygen sensor, rendering them useless.

4.5 Should I use this additive?

Synthetic oil - Mazda specifically says not to use synthetic oils in your RX-7 on page 7-11 of the owner's manual. So, for warranty purposes, you do not want to use synthetic oil. Some people on the RX-7 net have run synthetic oil in their cars with no ill effects, Pettit racing recommends using synthetic oil in the RX-7. If you choose to use synthetics or not, the most important thing to remember is to change the oil and filter regularly, at 3000 mile intervals, or less.
Slick 50 - Slick 50 claims to reduce engine wear because it contains PTFE. PTFE has been proven to break down when used in engines, and thus Slick 50 would not provide any additional protection.
Octane boost - You do not want to buy regular, 87 octane gas and then rely on octane boost to meet the minimum octane rating required by your car. Buy the good gas to begin with.
Water Wetter - use Redline's Water Wetter in my car, and it seems to run slightly cooler than it does on a 50/50 antifreeze mix.
Oil premix - Pettit sells an oil premix to be added to the gas tank called "Protek-R". It probably won't hurt the engine, but if you have a functioning oil metering system, it probably won't help either.
RedLine MTL - The net consensus is that Redline's MTL appears to help the shifting on cold mornings and reduce notchiness in the 5-speed equipped RX-7s.
4.6 Why does my airbox have a hose that is not connected to to anything?

The hose that comes out of the right side of the airbox and goes down under the box is not supposed to connect to anything. It serves as an escape route for the air coming from the compressor bypass hose. It is not open to the rest of the airbox, and "dirty" air will not be drawn through it into your engine.

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What are some of the common problems with 3rd Gen RX-7s?

Oil pressure gauge reads 0 psi
No boost above 4500 RPM
Hood squeaks / rattles
Hand brake light comes on while driving
"Low Coolant" alarm goes off
Radio flashing "Err" code
Hesitation at 3000 RPM when cold
Paint problems
Battery death & leakage
Brake rotor warpage
Suspension clunk
Cracking factory wheels

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5.1.1 Oil pressure gauge reads 0 psi

Sometimes the connection between the oil pressure sending unit and the wire to the oil pressure gauge gets loose or dirty. The way to fix this is to clean the metal tab on the sending unit with some 0000 steel wool, and then re-install the gauge wire using some electrolytic silicone gel (like some sets of spark plug wires come with) to seal out grime.

5.1.2 No boost above 4500 RPM

This is usually caused by a vacuum line coming off of the "Charge Control Solenoid". The lines sometimes pop off while under boost. The solenoid in question is located under the upper intake plenum. Look in your shop manual on page F-10, the solenoid is item F. If a vacuum line has come off here, trim off the end of the line where it has become loose, and re-attach it to the solenoid. It is helpful to use wire-ties or a dab of sealant to keep them from coming off again in the future. Motorcycle shops also sell small, wire clamps that work well.

5.1.3 Hood squeaks / rattles

Squeaks: Lightly lube up the tops of the rubber hood stops and the latch. Rattles: Tighten the latch mechanism so it holds the hood to the rubber stops with light pressure. Latch rattles can also be temporarily fixed by wrapping a small amount of tape around the latch where it mates with the striker plate.

5.1.4 Hand brake light comes on while driving

The switch that controls the parking brake indicator light is located under the leather brake handle boot. Sometimes during acceleration the hand brake lever moves enough to activate the light. This problem can be fixed by building up the area of the handbrake that contacts the switch with a product like JB Weld.

5.1.5 "Low Coolant" alarm goes off

The "Low Coolant" alarm goes off when the low coolant sensor is not wet. This sensor is located on the back side of the aluminum coolant fill housing. Simply top off your coolant level to quiet the alarm (even though it may already look full).

5.1.6 Radio flashing "Err" code

This means the factory radio's anti-theft feature has been triggered. It can be reset by entering an unlocking code. For obvious reasons, I will not put the code in this FAQ. E-mail me at tcw@prismnet.com and include your VIN and I will tell you how to unlock your radio. Your dealership can also do this, but sometimes they charge a fee.

5.2.1 Hesitation at 3000 RPM when cold

No known cure. I think it is caused by the double throttle control. Its purpose is to prevent the engine from getting an overly lean fuel/air mix when you first start to accelerate. Now the way this system works is that when the engine is cold, (coolant below 175 degrees or so) the ECU opens the double throttle control solenoid, which supplies vacuum to the double throttle control actuator. This vacuum overcomes the spring tension that normally holds the double throttle butterfly open, and it closes. Now, think about what happens when you accelerate.... the engine pulls less vacuum, and starts to go towards positive manifold pressure as you build boost. With the vacuum going away, the plate returns to its open (normal when engine warm) position. This helps explain why the car doesn't hesitate when accelerating hard, and does when accelerating slowly. The decision by the ECU to operate the double throttle control system is affected by coolant temperature, and the current "map" that the ECU is using. The Double Throttle control only happens during starting, cold engine warm-up, and COLD engine with LIGHT LOAD operation. This map is also affected by the 20k mile switch, which is why many people say that the car never hesitated at 3000 RPM when it was new. The 20k mile switch does the same thing that the EL switch does.... it adds base RPM to the motor... which affects the ECU's decision as to what "map" it is currently operating in. This is just my personal theory, and may be wrong.

5.2.2 Paint problems

Some RX-7 owners have experienced problems with accelerated paint chipping and fading. Mazda has set aside some money to deal with this problem on a case-by-case basis. If your car has this problem, call the Mazda customer service line (800 222-5500) and ask to schedule a meeting with your local District Service Manager to have your paint inspected.

5.2.3 Battery death & leakage

Many people on the RX-7 mailing list have had their batteries die prematurely. The main cause seems to be excessive heat. Batteries don't do well with heat, and it gets quite hot under the hood of an RX-7. Hot batteries also tend to leak acid. One solution to this problem is to buy a sealed battery. Sealed batteries withstand heat and cold much better than normal batteries, and they do not leak. Sealed batteries cost a little more than regular batteries, but they also last longer and come with better warranties.

5.2.4 Brake rotor warpage

Brake rotors warp from excessive heat. Routinely braking hard from high speed, can cause warpage. Rotors have been replaced under the new-car warranty. The extended warranties generally don't cover rotors, since they are expected to be consumed with use. Many netters have had their rotors replaced under warranty.

5.2.5 Suspension clunk

Cars produced prior to May 31, 1992 came from the factory with noisy upper a-arm bushings. Your dealership will replace the bushings under warranty with a modified part.

5.2.6 Cracking factory wheels

Some people on the net have noticed cracks where their spokes join the rim. There seem to have been two manufacturers of stock rims, one type has a curved area where the spoke joins the rim, and the other joins at a 90 degree angle. All reported cases of cracking rims have been on the 90 degree type rims.

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6.1 Is my mileage unusually low?

The official EPA mileage ratings for the 3rd generation RX-7s is:

Manual transmission:
17 MPG City, 25 MPG Highway
Automatic transmission:
18 MPG City, 24 MPG Highway

Real world experiences from the net vary from this. A highly modified car has gotten higher than EPA predicted mileage, but this is the exception. Most people on the net get lower mileage, with 12 MPG in mixed city and highway driving being a common number.

6.2 How much oil should my car consume?

The RX-7's engine consumes oil by design. It has oil metering pumps that actually inject oil into the combustion chambers to be burned as you drive. The amount you use will be determined by how aggressively you drive.

6.2 Sometimes my car backfires, is this bad?

No. Backfiring is caused by unburned fuel being ignited in your exhaust system. Backfiring in itself, although annoying, is not harmful. Excessive backfiring can be an indication of another problem.

6.3 What is typical 3rd Gen performance?

A typical, stock 3rd Gen should be able to turn about a 14.2 or better in the quarter mile, and a low 5 second, or better, 0 to 60 time.

6.4 What are normal boost patterns?

According to the official Mazda test procedure, boost should be as follows:

Drive to third gear with normal acceleration
Accelerate from 35 MPH at WOT until passing 4500 RPM
A slight and smooth increase in power should be felt at approximatly 4500 RPM. This will be about 65 MPH.
Boost should be above 10 PSI up to 4500 RPM. The boost will drop to about 8 PSI just after 4500 RPM, and will begin rising towards maximum boost depending on the length of time the throttle is held wide open.

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