System Performance Test 5 (TPS Wide Open Throttle Spectrum)
- Ground terminal "A" on ALDL with engine idling. Connect dwell meter (6-cyl. scale) to dwell lead at carburetor. Warm engine until dwell starts to vary.
- Connect jumper between ECM terminals No. 5 and 22 and note dwell. See Figure . If dwell changes to less than 20 degrees, go to step 3). If dwell does not change, check ECM connections. If connectors are okay, replace ECM.
- Remove jumper wire at ECM. With ignition on and engine off, check voltage from ECM terminal No. 5 to 22 while depressing accelerator pedal. If there is no voltage, go to step 4). If voltage decreased from greater than 3 volts (idle) to less than 3 volts (wide open throttle), perform SYSTEM PERFORMANCE TEST 1.
- If voltage is greater than 6 volts, repair short to battery voltage to ECM terminal No. 5, 7 or 22. If voltage is 2-6 volts, check TPS assembly.
- If voltage is less than 2 volts, in step 4). Check open wire or grounded wire to ECM terminal No. 5 or 7, if okay check TPS assembly.