Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1983 Isuzu Impulse AutomaticFACTORY OEM SERVICE PROCEDURE
Test 13: Fuel Injector Circuits (Code 33)
- Disconnect MCU terminal connectors at MCU, and fuel injectors. Check circuits between pin 21 and injectors A and B. Check circuits between pin 22 and injectors C and D. Repair or replace circuits that do not have continuity or are grounded.
- Turn ignition on. Check for 12 volts at dropping resistor side of fuel injector terminals. If voltage is not present, check dropping resistor, main relay and ignition switch.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.