Chart A-3 Engine Cranks But Will Not Run
Fig. 002 WIRING DIAGRAM for Chart A-3 Engine Cranks But Won't Run. VIN 1:
CHART A-3
ENGINE CRANKS BUT WON'T RUN
(Page 1 of 3)
2.0L (VIN 1) "J" SERIES
FUEL INJECTION (TBI)
Circuit Description:
Before using this chart, battery condition, engine cranking speed, and fuel quantity should be checked and verified as being OK.
Fig. 001 Chart A-3 - Engine Cranks But Won't Run:
Test Description:
Step numbers refer to step numbers on diagnostic chart.
1. A "Service Engine Soon" light "ON" is a basic test to determine if there is a 12 volt supply and ignition 12 volts to ECM. No ALDL may be due to an ECM problem, and CHART A-2 will diagnose the ECM. If TPS is over 2.5 volts, the engine may be in the clear flood mode, which will cause starting problems. The engine will not start without reference pulses and, therefore, the "Scan" should read rpm (reference) during cranking.
2. Because the Direct Ignition System uses two plugs and wires to complete the circuit of each coil, the opposite spark plug wire, should be left connected. If rpm was indicated during crank, the ignition module is receiving a crank signal, but "No Spark" at this test indicates the ignition module is not triggering the coil.
3. While cranking engine, there should be no fuel spray with injector disconnected. Replace the injector, if it sprays fuel or drips like a leaking water faucet.
4. The test light should blink, indicating the ECM is controlling the injectors OK. How bright the light blinks is not important. However, the test light should be a BT 8329 or equivalent.
5. Fuel Spray from the injector indicates that fuel is available. However, the engine could be severely flooded due to too much fuel. No fuel spray from injector indicates a faulty fuel system or no ECM control of injector.
Diagnostic Aids:
a. Water or foreign material can cause a no start during freezing weather. The engine may start after 5 or 6 minutes in a heated shop. The problem may not re-occur until an overnight park in freezing temperatures.
b. An EGR sticking open can cause a low air/fuel ratio during cranking. Unless engine enters "Clear Flood" at the first indication of a flooding condition, it can result in a no start.
c. Fuel pressure: Low fuel pressure can result in a very lean air/fuel ratio. See CHART A-7.
Fig. 004 WIRING DIAGRAM for Chart A-3 Engine Cranks But Won't Run. VIN 1:
CHART A-3
ENGINE CRANKS BUT WON'T RUN
(Page 2 of 3)
2.0L (VIN) "J" SERIES
FUEL INJECTION (TBI)
Circuit Description:
A magnetic crank sensor is used to determine engine position, much the same way as the pick-up coil did in HEI type systems. The sensor is mounted in the block, near a slotted wheel on the crank shaft. The rotation of the wheel creates a flux change in the sensor, which produces a voltage signal. The DIS ignition module then processes this signal and creates the reference pulses needed by the ECM and the signal triggers the correct coil at the correct time.
If the "Scan" tool did not indicate cranking rpm, and there is no spark present at the plugs, the problem lies in the Direct Ignition System or the power and ground supplies to the module.
Fig. 003 Chart A-3 - Engine Cranks But Won't Run:
Test Description:
Step numbers refer to step numbers on diagnostic chart.
1. Because the Direct Ignition System uses two plugs and wires to complete the circuit of each coil, the opposite spark plug wire should be left connected.
2. This test will determine if the 12 volt supply and a good ground is available at the DIS ignition module.
3. This test will determine if the ignition module is not generating the reference pulse, or if the wiring or ECM are at fault. By touching and removing a test light to 12 volts on CKT 430, a reference pulse should be generated. If rpm is indicated, the ECM and wiring are OK.
4. This test will determine if the ignition module is not triggering the problem coil or if the tested coil is at fault. This test could also be performed by using another known good coil.
Fig. 006 WIRING DIAGRAM for Chart A-3 Engine Cranks But Won't Run. VIN 1:
CHART A-3
ENGINE CRANKS BUT WON'T RUN
(Page 3 of 3)
2.0L (VIN 1) "J" SERIES
FUEL INJECTION (TBI)
Circuit Description:
Ignition voltage is supplied to the fuel injector on CKT 439. The injector will be pulsed (turned "ON" and "OFF"), when the ECM opens and grounds injector drive CKT 467.
Fig. 005 Chart A-3 - Engine Cranks But Won't Run:
Test Description:
Step numbers refer to step numbers on diagnostic chart.
1. No light indicate no ECM control of the injector or a wiring problem.
2. A steady light indicates that injector driver CKT 467 is grounded.