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.
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HOMESERVICE MANUALSCHEVROLET1994C 2500 SUBURBAN 2WD V8-350 5.7LREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTIGNITION SYSTEMIGNITION TIMINGADJUSTMENTS
1994 Chevrolet C 2500 Suburban 2WD V8-350 5.7L
Ignition Timing: Adjustments
1994 Chevrolet C 2500 Suburban 2WD V8-350 5.7LSECTION Adjustments
NOTE: Timing specifications are listed on the Vehicle Emissions Control Information label under the hood. Always follow the Vehicle Emissions Control Information label procedures first before using the following procedure.

PROCEDURE:
Set timing under the following conditions:
- Normal operating temperature.
- Air cleaner installed.
- A/C "OFF."
- Transmission in neutral.
- Disconnect SET TIMING connector. The location of the set timing connector is inside the cab where the heater box and the carpet meet on the passenger side floor. Pull carpet back to expose the single wire and connectors on the outside of the control module harness. The wire colors are tan with a black stripe.
DO NOT disconnect 4 wire connector at distributor.
Connect timing light and adjust as necessary by loosening hold down bolt and rotating distributor. For specification, refer to SPECIFICATIONS/TIMING MARKS. Tighten hold down and recheck the timing. Stop the engine and connect SET TIMING connector. Clear control module trouble code by disconnecting control module power source. With engine at operating temperature, drive vehicle at part throttle with moderate acceleration and decelerate to idle condition. This will "teach" the control module and return the engine to normal performance.
Timing Mark:
PROCEDURE:
Set timing under the following conditions:
- Normal operating temperature.
- Air cleaner installed.
- A/C "OFF."
- Transmission in neutral.
- Disconnect SET TIMING connector. The location of the set timing connector is inside the cab where the heater box and the carpet meet on the passenger side floor. Pull carpet back to expose the single wire and connectors on the outside of the control module harness. The wire colors are tan with a black stripe.
DO NOT disconnect 4 wire connector at distributor.
Connect timing light and adjust as necessary by loosening hold down bolt and rotating distributor. For specification, refer to SPECIFICATIONS/TIMING MARKS. Tighten hold down and recheck the timing. Stop the engine and connect SET TIMING connector. Clear control module trouble code by disconnecting control module power source. With engine at operating temperature, drive vehicle at part throttle with moderate acceleration and decelerate to idle condition. This will "teach" the control module and return the engine to normal performance.
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.