S10/T10 Blazer 4WD V6-4.3L VIN W (1997)
If no trouble is found in the fuel pump circuit or the ignition system and the cause of an Engine Cranks But Will Not Run has not been found, check for
the following conditions:
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Fouled spark plugs
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An EGR valve stuck open
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Low fuel pressure. Refer to Fuel System Pressure Test See: Computers and Control Systems/Testing and Inspection/Component Tests and
General Diagnostics/Fuel System Pressure Test
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Water or foreign material in the fuel system
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A grounded Ignition Control (IC) signal circuit may cause a No Start or a Start then Stall condition
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Basic engine problem
The VCM has integrated IC circuits that are fault protected; therefore, if a circuit has tailed, the failure may not damage the integrated IC. If that is the
case, the IC will keep the circuit open until the fault in the circuit has been corrected. When the fault has been corrected, reinstall the VCM. Check the
circuit. Replace the VCM only if the circuit is still inoperative.
Test Description
The numbers below refer to the step numbers on the diagnostic tables.
2. If the signal is over 2.5 volts, the engine may be in the clear flood mode which will cause starting problems.
3. If the engine coolant sensor is below -30°C, the VCM provides fuel for this extremely cold temperature which will severely flood the engine.
5. This step checks the ignition feed circuit to the injectors.
6. Voltage at the spark plug is checked using the spark plug tester tool J 26792. No spark indicates a basic ignition problem.
7. This test determines if there is fuel pressure at the fuel injection unit and holding steady.
