RX7 2RTR-1308cc 80 (1984)
Altitude Compensator: Technical Service Bulletins
Altitude Compensator Valve - Poor Driveability
Category Applicable Model/s Subject
Bulletin No. 014/85
4
RX-7 (12A)
ALTITUDE COMPENSATOR VALVE
Issued
8/21/85
Revised
DESCRIPTION
An altitude compensator valve is attached to the 1981-1985 RX-7 carburetor to supply additional air into the carburetor at high altitudes (between
1640-4920 ft.) in order to lean the mixture for better driveability. If the altitude compensator remains open at low altitudes, the following driveability
problems may occur:
^
Lack of acceleration, hesitation on acceleration
^
No power under load
^
Engine stumble, surge or bucking below approximately 3000 rpm
^
Rough idle
If the above driveability problems are encountered in RX-7 (12A), always check the altitude compensator as shown below before repairing the
carburetor.
PARTS INFORMATION
PART NUMBER
DESCRIPTION
APPLIED MODEL
N249 20 770
Altitude Compensator Valve
1981-1985 RX-7
Altitude Compensator Valve
CHECKING PROCEDURE
1.
Remove the altitude compensator valve.
2.
Blow through the valve from port A and
B.
Check that:
^
Above 4920 feet - air into port A exits from port D and air into port B exits from port C.
^
Below 1640 feet - air does not pass. If not, replace the altitude compensator valve.
NOTE:
The operating specification of the altitude compensator valve will vary between 1640-4920 feet depending on atmospheric pressure.
