Engine Controls - Adjustments: Diagnosis Chevrolet Prizm I

Metro & Firefly (Canadian) 1.0L (With Scan Tool)

1. Perform On-Board Diagnostic (OBD) System Check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article. After performing OBD system check, go to next step.
2. Ensure ignition timing is within specification. See «IGNITION TIMING»(ref-165-S23146442352000030800000) . Place transaxle in Park (A/T) or Neutral (M/T). Apply parking brake and block drive wheels. Ensure all emission hoses and air cleaner are properly installed. Start engine and allow it to reach normal operating temperature. Ensure throttle cable has free movement and some free play. Ensure all accessories and A/C (if equipped) are turned off. Connect scan tool to Data Link Connector (DLC). Using scan tool, ensure idle speed is within specification. See «IDLE SPEED SPECIFICATIONS»(ref-165-S27964935742000030800000) table.
3. If idle speed is not within specification, check Idle Speed Control (ISC) system. DO NOT attempt to manually adjust idle speed. Damage to ISC system may occur.

Metro & Firefly (Canadian) 1.3L (With Scan Tool)

1. Perform On-Board Diagnostic (OBD) System Check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article. After performing OBD system check, go to next step.
2. Place transaxle in Park (A/T) or Neutral (M/T). Apply parking brake and block drive wheels. Ensure all emission hoses and air cleaner are properly installed. Start engine and allow it to reach normal operating temperature. Ensure throttle cable has free movement and some free play. Ensure all accessories are turned off. Connect scan tool to Data Link Connector (DLC). Using scan tool, ensure idle speed is within specification with A/C on and off (if equipped). See «IDLE SPEED SPECIFICATIONS»(ref-165-S27964935742000030800000) table.
3. If idle speed is not within specification, check Idle Air Control (IAC) system. DO NOT attempt to manually adjust idle speed. Damage to IAC system may occur.

Metro & Firefly (Canadian) 1.3L (Without Scan Tool)

1. Place transaxle in Park (A/T) or Neutral (M/T). Apply parking brake and block drive wheels. Ensure all emission hoses and air cleaner are properly installed. Start engine and allow it to reach normal operating temperature. Ensure throttle cable has free movement and some free play. Ensure all accessories and A/C (if equipped) are turned off.
2. Connect a tachometer to vehicle. Access 6-pin duty check Data Link Connector (DLC), located next to PCM behind glove box. Connect a fused jumper wire between duty check DLC cavities No. 2 and 4. see scheme 2 Connect a DVOM between duty check DLC cavities No. 4 and 6. Select DC voltage scale and duty cycle (HZ) or dwell on DVOM.
3. Monitor tachometer and DVOM. Ensure idle speed is within specification. See «IDLE SPEED SPECIFICATIONS»(ref-165-S27964935742000030800000) table. If idle speed is not within specification, check Idle Air Control (IAC) system. DO NOT attempt to manually adjust idle speed. Damage to IAC system may occur.

Inspection

1. Insert a.140" (3.5 mm) feeler gauge between throttle stop screw and throttle lever. (Scheme 1) If Idle Speed Control (ISC) motor plunger is contacting throttle lever screw, bring engine to normal operating temperature.
2. Ensure ignition is off. Using a DVOM, backprobe between ground and TP sensor signal circuit terminal at PCM harness connector. See appropriate wiring diagram in WIRING DIAGRAMS article. Turn ignition on. If voltage is 0.98-1.02 volts, TP sensor is adjusted properly. If voltage is not as specified, see «ADJUSTMENT»(ref-165-S33404519222000030800000).

With feeler gauge still placed between throttle stop screw and throttle lever, loosen TP sensor retaining screws. Rotate TP sensor until voltage reading is 0.98-1.02 volts. Tighten TP sensor retaining screws to 18 INCH lbs. (2.0 N.m). Replace TP sensor if specified voltage cannot be obtained.

Scheme 1