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.
Symptom Definition
1995 GMC Rally G2500, 4.3 ZSECTION Symptom Definition
Engine starts but will not run at idle. Engine runs if accelerator is held at part throttle.
Possible Causes & Corrections:
- Problem is most likely in Idle Air Control (IAC) system. See DIAGNOSTIC AIDS in DTC 35 chart in appropriate TESTS W/CODES article below.
- TESTS W/CODES - 2.2L
- TESTS W/CODES - 3.1L
- TESTS W/CODES - 3.8L
- TESTS W/CODES - 4.3L
- TESTS W/CODES - 5.0L
- TESTS W/CODES - 5.7L
- Check EGR system.
- Check park/neutral switch.
- Disconnect MAP sensor. If condition is corrected, replace sensor.
RENDER: 1.0x
NO RELATED
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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.