Bronco L6-300 4.9L VIN Y 1-bbl (1983)
Idle/Altitude Compensator (Non Comp. Controlled): Testing and Inspection
ELECTRICAL
1.
Check and record engine timing.
2.
Disconnect compensator from ignition module and connect suitable jumper wire across module connectors. Recheck engine timing.
3.
At altitudes of 4000 ft. or lower, timing should be advanced 4° on V8-302 engine, or 6° on V8-351 engine.
4.
At altitudes of 4000 ft. or higher on 6-300 engine, or 4600 ft. or more on V8-302 and V8-351 engines, there should be no change in timing.
Fig. 8 Mechanical type altitude compensator
MECHANICAL
1.
Connect a suitable vacuum gauge to air inlet nipple, Fig. 8, and check for vacuum with engine running.
2.
On 4-140 engine, there should be no vacuum at altitudes of 2500 ft. or lower and vacuum should be present at altitudes of 3000 ft. or higher.
3.
On V6-232 engines, there should be no vacuum at altitudes of 3500 ft. or lower and vacuum should be present at altitudes of 4000 ft. or higher.
