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.

SYS.OK|MANUAL.DB● LIVE

HOMESERVICE MANUALSCHEVROLET1985IMPALA 5.7 N, 200C/MV9REPAIR AND DIAGNOSISENGINE PERFORMANCESYSTEMCCC 4.3L TBI TESTS W/CODESBASIC DIAGNOSTIC PROCEDURE

1985 Chevrolet Impala 5.7 N, 200C/MV9

Basic Diagnostic Procedure

1985 Chevrolet Impala 5.7 N, 200C/MV9SECTION Basic Diagnostic Procedure

Diagnosis of the CCC system should be performed in the following order:

Make sure that all engine systems not related to the CCC system are operating properly. Do not proceed with testing unless all other problems have been repaired.
Put the system into diagnostic mode and record trouble codes flashed by "CHECK ENGINE" light. Exit the diagnostic mode.
If trouble codes were displayed, decide whether the codes are "hard" or "intermittent" trouble codes.
Proceed to Diagnostic Circuit Check chart. Follow all instructions given in that chart.
If no trouble codes were displayed, proceed to Field Service Mode for fuel injection models.
If no trouble is indicted by any of these charts, use the TROUBLE SHOOTING material in the CCC TESTS W/O CODES article in this section. The comments there will send you to the proper component charts or tell you what to fix.
After any repairs are made, perform System Performance Check. Clear any trouble codes.

NOTE: Each of the steps listed here are described later in this section. If you are unsure of the proper way to test, read through the following material.

RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready Tools Free Quote Check Quote Shield Pro

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.