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RX-7 Unflooding Procedure
79-85 12A Carbureted

Overview

We have included some background information on this condition to help avoid the situation in the future. The actual unflooding procedure has been divided into two segments. One is an easy "two-step" process which can be done by anyone. It is effective in 90% of all flooded conditions. This procedure should always be tried before attempting the complex process. Since the complex process involves pulling the spark plugs, only people with adequate tools and mechanical aptitude should attempt it.

Common Symptoms

  • Vehicle was running fine the last time I parked it, but now it won't start
  • I can hear the engine rotating, but it sounds strange. Also, I smell gasoline.
  • I moved my car from the garage to the street, turned it off and now it won't start.
  • My car has been sitting for a long time and won't start.

Background

The RX-7 is well known for flooding problems. One of the most common is caused by a "short start" condition. The "short start" is when someone starts the vehicle and turns it off before it is allowed to reach full operating temperature. The typical situation is moving the vehicle from one parking spot to another(ex: from garage to driveway). Cooler weather, especially temperatures below 70 degrees, aggravate the situation. What has happened, is the engine is still in the cold-start warmup cycle. Fortunately, the carbureted model of the RX-7 is the least prone to flooding problems. However, they are prone to easily flooding if vehicle sits for an extended period. If consistent starting problems are experienced outside of the short-start situation or a non-start due to extended inactivity, service is probably needed to the vehicle.

Rules of thumb

  • You will have to actively unflood the vehicle. RX-7's WILL NOT unflood themselves, even if allowed to sit for long periods of time.
  • If car is heavily flooded, spark plug replacement and oil changing may be required.
  • There is no cure for the short start problem other than the discipline to avoid the situation
  • ALWAYS ALLOW THE VEHICLE TO REACH FULL OPERATING TEMPERATURE BEFORE TURNING ENGINE OFF

Easy 2-Step Method(1979-85 carbureted)

PREPARATION

Battery needs to still have a reasonable charge. If engine is cranking slowly, please charge battery first or connect jumper cables.

SUPPLIES

Qt. Automatic transmission fluid(ATF)-any type or brand

STEP ONE

Locate air filter housing on passengers side of engine compartment. Remove lid from air filter housing. Identify two smaller barrels of the 4-barrel carburetor. Pour approx. one ounce of automatic transmission fluid(ATF)in each of the two smaller barrels. Reinstall carburetor lid.


Typical aircleaner arrangement
Two smaller barrels viewed from passengers side
STEP TWO

Get back in vehicle and pump gas approximately five times. Start car with accelerator held firmly to the floor. Engine should start and release throttle. Set choke as needed to keep engine running. Note: Exhaust will smoke EXTREMELY heavily once started. The more the engine was flooded, the more it will smoke. If flooded very badly, it is recommended to change the engine oil at earliest convenience.

 

Complex Unflooding Procedure(1979-85 carbureted)

Note: This procedure is only to be done by persons with adequate tools and experience. Also, it is intended to be done after attempts to unflood with the Easy 2-step Method have failed.

TOOLS
  • Standard 13/16 spark plug socket and ratchet
  • One quart automatic transmission fluid(ATF)-any type
  • NGK spark plug set(if needed)

    PREPARATION

    Battery needs to still have a reasonable charge. If engine is cranking slowly, please charge battery first or connect jumper cables.

    STEP ONE

    Engine has (4)spark plugs arranged in a square pattern on the drivers side of engine. Please label each plug wire and remove all four plugs. Note: It is absolutely imperative that the wires be able to go back onto the correct spark plug hole when the procedure is completed. Also, make sure plug wires are out of the way of the accessory belts to avoid tangling when engine cranked in step two.


    Spark plug side of engine
    Another version of plug side of engine

    Trace wires from dist cap to plugs
    Spark plug side of engine

    STEP TWO

    Make sure all four spark plugs are pulled and wires are away from accessories and belts. Get inside of vehicle, hold accelerator on floor, and crank engine for approx. 15~20 seconds. Engine WILL NOT start during this procedure.

    STEP THREE

    Examine original spark plugs. Clean and dry carefully, if still in acceptable condition. Use a brand new set of NGK plugs, if necessary.
    Install plugs and reattach spark plug wires. Note: As mentioned before, it is absolutely imperative that the right wire go to the right hole. Wires can be traced one-by-one from their distributor cap connection. Each cap connection is labeled L1, L2, T1 or T2. Remember T stands for top, L for lower, 1 for front and 2 for rear.

    STEP FOUR

    Locate air filter housing on passengers side of engine compartment. Remove lid from air filter housing. Identify two smaller barrels of the 4-barrel carburetor. Pour approx. one ounce of automatic transmission fluid(ATF)in each of the two smaller barrels. Reinstall carburetor lid.


    Typical aircleaner arrangement
    Two smaller barrels viewed from passengers side

    STEP FIVE

    Get back in vehicle and pump gas approximately five times. Start car with accelerator held firmly to the floor. Engine should start and release throttle. Set choke as needed to keep engine running. Note: Exhaust will smoke EXTREMELY heavily once started. The more the engine was flooded, the more it will smoke. If flooded very badly, it is recommended to change the engine oil at earliest convenience.

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