Engine Controls - Adjustments Honda Prelude III рестайлинг

ENGINE COMPRESSION

Check compression pressure with engine at normal operating temperature, all spark plugs removed, throttle valves wide open and at specified cranking speed. Crank engine at least 6 revolutions to determine engine compression. Compression reading should be as specified in ENGINE COMPRESSION table.

ENGINE COMPRESSION (1)

Scheme 1

Scheme 2

1. With engine cold, remove valve cover, spark plugs and distributor cap. Adjustment of exhaust and intake valves are done at the same time.
2. Rotate crankshaft to bring No. 1 piston to TDC on compression stroke. UP marks on camshaft pulleys should be at top and TDC grooves on camshaft pulleys should align with cylinder head surface. (Scheme 1) Distributor rotor should point to No. 1 spark plug wire on cap.
3. Loosen lock nuts on valves for No. 1 cylinder and adjust valve clearances to specification. See «VALVE CLEARANCE ADJUSTMENT SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table. (Scheme 2) Tighten lock nuts to specification. See «TORQUE SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments__torque-specifications) at the end of this article. Recheck valve clearance.
4. Rotate crankshaft until next cylinder is at TDC. For remaining cylinders, repeat steps 3) and 4).
5. Replace valve cover and distributor cap. Tighten nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments__torque-specifications) at end of this article.

Scheme 3

Scheme 4

1. With engine cold, remove valve cover, spark plugs and distributor cap. Adjustment of exhaust and intake valves are done at the same time.
2. Rotate crankshaft to bring No. 1 piston to TDC on compression stroke. UP mark on camshaft pulley should be at top and TDC grooves on camshaft pulley should align with cylinder head surface. (Scheme 3) Distributor rotor should point to No. 1 spark plug wire on distributor cap.
3. Loosen lock nuts on valves for No. 1 cylinder and adjust valve clearances to specification. See «VALVE CLEARANCE ADJUSTMENT SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table. (Scheme 4) Tighten lock nuts to specification. See «TORQUE SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments__torque-specifications) at the end of this article. Recheck valve clearance and repeat adjustment if necessary.
4. Rotate crankshaft until next cylinder is at TDC. Repeat step 3). Repeat steps 3) and 4) for remaining cylinders.
5. Replace valve cover and distributor cap. Tighten nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments__torque-specifications) at end of this article. VALVE CLEARANCE ADJUSTMENT SPECIFICATIONS Model Intake - In. (mm) Exhaust - In. (mm) Accord.009-.011 (.23-.28).011-.013 (.28-.32) Civic.007-.009 (.17-.23).009-.011 (.23-.28) CRX HF.005-.007 (.13-.17).007-.009 (.17-.23) CRX Std. & Si.007-.009 (.17-.23).009-.011 (.23-.28) Prelude Carbureted.005-.007 (.13-.17).010-.012 (.25-.30) Fuel-Injected.003-.005 (.08-.13).006-.008 (.16-.20)

Scheme 5

Scheme 6

1. Disconnect and check vacuum signal to vacuum advance hoses at vacuum advance unit. With engine running and coolant temperature less than 140°F (60°C), check for vacuum at each hose. Vacuum should be present at hoses No. 2 and No. 25. (Scheme 5)
2. If hose No. 2 has no vacuum, check hose for leaks or other damage. If hose No. 25 has no vacuum, check thermovalve for blockage and hose for leaks or other damage. If there is no blockage and hoses are okay, replace thermovalve.
3. Reconnect vacuum hoses to vacuum advance unit. Allow engine to reach operating temperature (cooling fan comes on). Disconnect vacuum hose No. 25 from vacuum advance unit. (Scheme 5) Check vacuum signal. No vacuum should be present. If vacuum is present, replace thermovalve and retest.
4. To view timing marks, remove rubber cap from inspection window on cylinder block. Connect timing light with timing advance capability. (Scheme 6) Disconnect and plug vacuum hoses at vacuum advance unit.
5. With engine at idle, turn advance control knob of advance tester until White timing mark aligns with pointer. Read base ignition timing shown on timing advance meter. Timing should be as specified in «IGNITION TIMING»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table.
6. Rotate distributor to adjust timing. Tighten distributor hold-down bolts to specification after adjustment. See «TORQUE SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments__torque-specifications) at the end of this article.
7. Recheck timing. Reconnect vacuum hoses to vacuum advance unit. Timing should advance to Red timing mark. See «IGNITION TIMING»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table. If timing does not advance, check vacuum advance diaphragm and distributor centrifugal advance mechanism. See SYSTEM/COMPONENT TESTS article.

Scheme 7

Scheme 8

1. Remove rubber cap from inspection window on bellhousing of cylinder block. Start and warm engine to normal operating temperature (cooling fan comes on). Connect a jumper wire between Orange/Red and Green/White wire terminals of ignition timing check connector located in passenger side kick panel. (Scheme 7)
2. Connect a timing light to No. 1 spark plug wire. Check base ignition timing with timing light. See «IGNITION TIMING»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table. Timing pointer is on flywheel for manual transmissions and on drive plate for automatic transmissions. (Scheme 8)
3. Loosen hold-down bolts, and rotate distributor to adjust timing. Tighten distributor hold-down bolts to specification after adjustment. See «TORQUE SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments__torque-specifications) at the end of this article. Recheck timing.
4. Remove timing light. Remove jumper wire from ignition timing check connector. Install rubber cap to inspection window.

Scheme 9

Scheme 10

Scheme 11

1. To view timing marks on Prelude, remove rubber cap from inspection window on cylinder block by bellhousing. On Civic and CRX, timing marks are on timing belt cover and crankshaft pulley. Start and warm engine to normal operating temperature (cooling fan comes on). Connect timing light.
2. Remove Yellow rubber cap from ignition timing check connector located under dash on Civic and CRX, or behind ignition coil on Prelude. Connect jumper wire between Brown and Green/White wire terminal connectors. (Scheme 9)and (Scheme 10).
3. Check ignition timing and adjust to specification, if necessary. See «IGNITION TIMING»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table. To adjust, loosen distributor hold-down bolts and turn distributor housing counterclockwise to advance or clockwise to retard timing.
4. Tighten distributor hold-down bolts to specification after adjustment. See «TORQUE SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) at the end of this article. Recheck timing. Remove jumper wire from ignition timing check connector. Replace rubber cap in inspection window on Prelude. IGNITION TIMING (Degrees BTDC @ RPM) Application Setting Accord 13-17 @ 700-800 Civic (1) 16-20 @ 700-800 CRX HF 12-16 @ 550-650 Si 16-20 @ 700-800 Std. 16-20 @ 675-775 Prelude Carbureted Initial Setting Automatic Transmission 4 @ 700-800 Manual Transmission 4 @ 750-850 Final Setting Automatic Transmission (2) (3) 13-17 @ 700-800 Manual Transmission (4) 18-22 @ 750-850 Fuel Injected 13-17 @ 700-800 (1) Red mark on crankshaft pulley. (Scheme 11) (2) 8-12 degrees BTDC on California vehicles. (3) Automatic transmission in Neutral. (4) 13-17 degrees BTDC on California vehicles.

Scheme 12

1. Disconnect Red-braided purge hose from purge canister. Connect vacuum gauge to hose. Connect tachometer to engine. Start and warm engine to normal operating temperature (cooling fan comes on).
2. Increase engine speed to 3000 RPM by turning throttle stop screw. (Scheme 12) Note vacuum gauge reading. While engine speed is at 3000 RPM, pinch Red vacuum hose under choke housing and note vacuum gauge reading.
3. If vacuum gauge reading did not change, the carburetors are properly synchronized. If readings were different, adjust the synchronization screw until vacuum gauge reading does not change. (Scheme 12)
4. Remove tachometer and vacuum gauge. Reconnect purge hose to canister. Readjust idle speed. See «IDLE SPEED»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) in this article.

COLD (FAST) IDLE RPM (CARBURETED)

Note. Cold (fast) idle RPM on fuel injected models is not adjustable.

Scheme 13

Scheme 14

1. Warm engine to normal operating temperature (cooling fan comes on). Turn engine off. Relieve pressure from cooling system and partially drain radiator. Disconnect both coolant hoses from thermowax valve located next to throttle controller on left carburetor. Cap coolant hoses.
2. Apply cold water to thermowax valve to cool wax. Connect tachometer to engine. Start engine and check idle speed. (Scheme 13) Adjust fast idle RPM, if necessary, by turning fast idle adjusting screw. (Scheme 14)
3. If fast idle speed cannot be adjusted to specification, replace left carburetor. See «N - REMOVE/INSTALL/OHAUL»(/honda/prelude/iii-1989-1992/remont/removal-installation/#engine-controls-removeinstalloverhaul) article. Reconnect both coolant hoses. Start engine and warm to normal operating temperature (cooling fan comes on). Check fast idle lever. Fast idle lever should not be seated against fast idle cam. If seated, replace left carburetor. See «N - REMOVE/INSTALL/OHAUL»(/honda/prelude/iii-1989-1992/remont/removal-installation/#engine-controls-removeinstalloverhaul) article.

IDLE MIXTURE & CO LEVEL (PROPANE ENRICHMENT METHOD)

Note. Idle mixture is computer controlled on fuel injected models and is not adjustable. Maximum CO level is .1% on all models.

Scheme 15

1. Ensure carburetors are properly synchronized. See «CARBURETOR SYNCHRONIZATION»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) under IDLE SPEED & MIXTURE in this article. Start and warm engine to operating temperature (cooling fan comes on).
2. Disconnect and plug vacuum hose from intake air control diaphragm. Check fast idle lever and cam. Fast idle lever should not be seated against fast idle cam. If seated against fast idle cam, replace left carburetor. See «N - REMOVE/INSTALL/OHAUL»(/honda/prelude/iii-1989-1992/remont/removal-installation/#engine-controls-removeinstalloverhaul) article. Connect tachometer to engine.
3. Ensure automatic transaxle is in gear, parking brake is set, and all accessories and cooling fan are off. Check idle speed. See «IDLE SPEED SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table. If necessary, adjust idle speed by turning throttle stop screw. (Scheme 15) NOTE: If idle speed is excessively high, check throttle controller.
4. Unplug 2-pin connector from Electronic Air Control Valve (EACV). Disconnect vacuum hose from intake manifold hose, and cap end of hose. Disconnect vacuum hose from A/C idle boost throttle controller.
5. Disconnect air cleaner intake tube from air intake duct. Insert propane hose 4" into air intake tube. With engine idling, slowly open propane control valve to obtain maximum engine speed. See «IDLE SPEED & ENRICHED RPM INCREASE»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table.
6. If enriched RPM increase is correct, go to step 8). If engine speed does not increase, air/fuel mixture is improperly adjusted. Remove mixture adjustment screw hole plugs, adjust idle mixture and recheck enriched RPM.
7. If enriched RPM is low, lean out mixture by turning mixture adjustment screw clockwise 1/4 turn and recheck RPM. If enriched RPM is high, enrich mixture by turning mixture adjustment screw counterclockwise 1/4 turn and recheck RPM.
8. Close propane valve and connect EACV and vacuum hose to intake manifold hose. Remove ECU fuse in underhood fuse box for 10 seconds to reset ECU memory. Recheck idle speed. If necessary, repeat procedure until idle RPM and enriched RPM are correct.
9. Remove propane enrichment kit and connect air cleaner intake tube. If A/C equipped, check idle speed with A/C system on. See «IDLE SPEED SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table. If idle speed is not to specification, turn idle boost throttle controller screw to correct idle speed with A/C on. Install mixture adjustment screw hole plugs. IDLE SPEED & ENRICHED RPM INCREASE Application (1) Idle RPM Enriched RPM Increase Prelude (Carbureted) Automatic (2) 700-800 40-60 Manual 750-850 150-190 (1) Automatic transaxle in Park or Neutral, manual transaxle in Neutral. (2) With transaxle in gear, idle speed should be 650-750 RPM. Check enriched RPM increase with transaxle in gear.

Scheme 16

1. Start and warm engine to normal operating temperature (cooling fan comes on). Connect tachometer. Disconnect 2-wire Electronic Air Control Valve (EACV) connector. Ensure all accessories and cooling fan are off. Check idle speed. See «IDLE SPEED SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table.
2. Adjust idle speed by turning idle adjusting screw, if necessary. (Scheme 16) Turn ignition off. Reconnect 2-wire EACV connector. Remove BACK-UP fuse from underhood relay box for 10 seconds to reset ECU. Restart engine. Check idle speed with all accessories off. See «IDLE SPEED SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table.
3. Idle engine for one minute with various accessories on and check idle speed. See «IDLE SPEED SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table. Idle speed should be stable and within specification. If idle is not within specification, see «H - TESTS W/O CODES»(/honda/prelude/iii-1989-1992/remont/testing-diagnostics/#engine-controls-tests-wo-codes) article.

Scheme 17

Scheme 18

1. Start and warm engine to normal operating temperature (cooling fan comes on). Connect tachometer. Disconnect 2-wire Electronic Air Control Valve (EACV) connector. Ensure all accessories and cooling fan are off. Check idle speed. See «IDLE SPEED SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table.
2. Adjust idle speed, (if necessary), by turning idle adjusting screw. (Scheme 17)and (Scheme 18). If idle speed is excessively high, check dashpot or throttle cable. Turn ignition off. Reconnect 2-wire EACV connector.
3. Remove HAZARD fuse from main fuse box for 10 seconds to reset ECU. Restart engine. Check idle speed with various accessories turned on. Idle speed should be stable and within specification. See «IDLE SPEED SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table. If idle is not within specification, see «H - TESTS W/O CODES»(/honda/prelude/iii-1989-1992/remont/testing-diagnostics/#engine-controls-tests-wo-codes) article.

Prelude (Carbureted)

See IDLE MIXTURE & CO LEVEL (PROPANE ENRICHMENT METHOD) under IDLE SPEED & MIXTURE in this article.

Scheme 19

1. Start and warm engine to normal operating temperature (cooling fan comes on). Connect tachometer to engine. Disconnect 2-wire EACV connector. Ensure steering wheel is in straight-ahead position, all accessories and cooling fan are off. Check idle speed. See «IDLE SPEED SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table.
2. Adjust idle speed by turning idle adjusting screw, (if necessary). (Scheme 19) Reconnect 2-wire EACV connector. Turn ignition off. Remove CLOCK fuse (in underhood relay box) for 10 seconds to reset ECU.
3. Restart engine. Check idle speed with headlights in high beam, and all accessories on, while turning steering wheel, and automatic transmission in gear. Idle should remain stable at the specified RPM. See «IDLE SPEED SPECIFICATIONS»(/honda/prelude/iii-1989-1992/remont/adjustments/#engine-controls-adjustments) table. If idle speed is not as specified, see «H - TESTS W/O CODES»(/honda/prelude/iii-1989-1992/remont/testing-diagnostics/#engine-controls-tests-wo-codes) article. IDLE SPEED SPECIFICATIONS (1) Application RPM Accord All Models 550-650 After ECU Reset No Load 700-800 Under Load 720-820 Civic 1.5L 575-675 1.6L 500-600 After ECU Reset 1.5L No Load 700-800 Under Load 760-860 1.6L No Load 700-800 Under Load 2WD 760-860 4WD Manual 760-860 Automatic 780-880 CRX HF 450-550 Si 500-600 Std. 575-675 After ECU Reset HF No Load California 600-700 Federal 550-650 Under Load 700-800 Si & Std. No Load 700-800 Under Load 760-860 Prelude Carbureted Automatic 700-800 Manual 750-850 After ECU Reset (A/C On) 700-800 Fuel-Injected 600-700 After ECU Reset 720-820 (1) Idle speed is set with headlights and cooling fan off and automatic transmission in Drive.

THROTTLE ANGLE (POSITION) SENSOR

Note. For servicing, see TESTS W/CODES article.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• N - REMOVE/INSTALL/OHAUL
• H - TESTS W/O CODES
• ENGINE COMPRESSION
• TORQUE SPECIFICATIONS
• IDLE MIXTURE & CO LEVEL (PROPANE ENRICHMENT METHOD)