Torque Converter Stall Test
CONVERTER STALL TESTA stall test consists of determining maximum engine speed obtained at full throttle in "D" and "R" positions. This test checks torque converter stator overrunning clutch operation, and holding ability of the transaxle clutches and the low-reverse brake.
Warning: During this test, make sure that no one stands in front of or behind vehicle.
1. Check transaxle fluid level. Fluid should be at normal operating temperature [70-80°C (158-176°F)]. Engine coolant should also be at normal operating temperature [80-95°C (176-205°F)].
2. Apply chocks to both rear wheels.
3. Attach engine tachometer.
4. Apply parking and service brakes fully.
5. Start engine.
6. With the selector lever in the "D" position, depress the accelerator pedal fully to read engine maximum rpm. Do not hold throttle wide open any longer than is necessary to obtain maximum engine rpm reading, and never longer than 5 seconds at a time. If more than one stall test is required, operate engine at approximately 1,000 rpm in neutral for 2 minutes to cool transaxle fluid between tests.
Stall speed : 2500 ± 300 rpm
7. Place the selector lever in the "H" position and perform the stall test by using the same procedure as above.
Stall Speed Above Specification in "D"
If the stall speed is higher than the specification, the rear clutch or the overrunning clutch of the transaxle is slipping. Perform a hydraulic test.
Stall Speed Above Specification in "R"
If the stall speed is higher than the specification, the front clutch of the transaxle or the low-reverse brake is slipping. Perform a hydraulic test.
Stall Speed Below Specification in "D" and "R"
If the stall speed is lower than the specification, insufficient engine output or a faulty torque converter can be suspected. Check for engine misfiring, improper ignition timing, valve clearance etc. If these are good, the torque converter is faulty.