18I/Sportwagon L4-2165cc 2.2L (1985)
4.
Check ignition voltage by connecting voltmeter positive probe to terminal D1-2 and negative probe to terminal D1-3, Fig. 3. There should be
approximately 12 volts.
5.
Check coolant temperature sensor by connecting ohmmeter probes between terminals D2-12 and D2-7, Fig. 3. With Electronic Control Unit
(ECU) disconnected, there should be 2.5k ohms at 68 degrees F or 320 ohms at 176 degrees F. With ECU connected, there should be 1.5k ohms at
68 degrees F.
6.
With ECU connected, check injectors by connecting ohmmeter test probes across pins A and B of injector wire harness connector, Figs. 9 and 10.
There should be a resistance value of 4 ohms.
7.
Check fuel pump by applying 12 volts with jumper wire between terminals D1-5 and D1-6, Fig. 3. Noise should be heard from fuel pump.
8.
Check throttle position switch as follows:
a. Connect ohmmeter test probes between terminals D2-13 and D2-6, Fig. 3. There should be infinite ohms.
b. Connect ohmmeter test probes between terminals D2-4 and D2-13 with throttle at idle position. There should be zero ohms.
c. Connect ohmmeter test probes between terminals D2-4 and D2-6 with throttle wide open. There should be zero ohms.
9.
Check thermo-time coolant switch by connecting voltmeter positive probe to terminal D2-9 and negative probe to terminal D2-7, Fig. 3. Operate
starter motor. There should be 8 to 12 volts present, then drop to 0 volts after a few seconds, depending on temperature.
10.
With engine temperature below 77 degrees F, check starting voltage by connecting voltmeter positive probe to terminal D1-4 and negative probe
to D1-3, then operate starter, Fig. 3. There should be 8 to 12 volts present.
11.
With engine temperature below 77 degrees F, check tach voltage by connecting voltmeter positive probe to terminal D1-1 and negative probe to
D1-3, then operate starter, Fig. 3. There should be oscillating voltage available.
12.
With coolant temperature below 77°F, and oxygen sensor temperature below 480°F, start engine. Check integrator voltage by connecting
voltmeter positive probe to terminal D2-2 and negative probe to D2-7, Fig. 3. There should be approximately 6.8 volts. Note reading.
13.
With engine running at 750 to 850 RPM, wait until coolant temperature exceeds 104°F and oxygen sensor temperature exceeds 480°F. Check
integrator voltage by connecting voltmeter positive probe to terminal D2-2 and negative probe to terminal D2-7, Fig. 3. Voltage should vary ± .5
volts with that noted in step 12.
14.
Increase engine speed to 3500 RPM and rapidly close throttle plate. Check fuel cut-off during deceleration by connecting voltmeter positive probe
to terminal D2-2 and negative probe to terminal D2-7, Fig. 3. Voltage should be the same as that noted in step 12.
FEEDBACK FUNCTION DIAGNOSIS
1.
If, with conditions described in step 12 of previous test, voltage was 12 volts, check for short circuit in sensor or check for air leak and repair or
replace as necessary.
2.
If voltage was zero volts, check temperature sensor and airflow meter and replace as necessary.
3.
If, when conditions are as described in step 13 of previous test, voltmeter does not move from position achieved when conditions were as
described in step 12, check that oxygen sensor is securely connected. If so, check for break in wiring.
