Engine Controls - Adjustments Volvo 960 I

ENGINE COMPRESSION

Warm engine to normal operating temperature. Disconnect single wire from negative terminal of ignition coil. Check compression with all spark plugs removed, throttle valve wide open and at normal cranking speed (250-300 RPM).

COMPRESSION SPECIFICATIONS

VALVE CLEARANCE

Note. 960 uses hydraulic lifters; adjustment is not necessary.

1. Remove valve cover. Turn crankshaft center bolt until camshaft is in position for firing No. 1 cylinder (TDC). Both cam lobes should point up at equally large angles. Pulley timing mark should be at zero degree mark.
2. Using a feeler gauge, check valve clearance of No. 1 cylinder between camshaft lobe and adjusting discs. Intake and exhaust valves have same clearance.
3. If clearances are incorrect, adjust by changing thickness of disc(s). Discs are available in .002" (.05 mm) increments in .13-.18" (3.30-4.50 mm) range. Install disc with markings facing down. Use Valve Depressor (5022) and Pliers (5026) to depress and remove disc(s).
4. After valves for No. 1 cylinder are properly adjusted, rotate crankshaft to firing position for No. 3, 4 and 2 cylinders in sequence and repeat procedure. Install valve cover.

VALVE CLEARANCE SPECIFICATIONS

IGNITION TIMING

Ignition timing is computer-controlled and is not adjustable.

IGNITION TIMING (Degrees BTDC @ RPM)

IDLE SPEED & MIXTURE

Note. Cold (fast) idle is computer-controlled. Adjustment procedure is not available. Basic idle speed adjustment procedure for 960 is also not available.

BASIC IDLE SPEED (240, 740 & 940)

1. Ground Red/White wire in 2-wire test lead. (Scheme 1) Test lead is located on right side of master cylinder. Grounding wire will set air valve wide open.
2. Use air bleed knob located under throttle body to set basic idle speed. See IDLE SPEED & CO LEVEL table. Disconnect ground wire from test lead. Engine speed should increase.

Scheme 1

IDLE SPEED & CO LEVEL (1)

Note. Idle mixture adjustment is not a normal tune-up procedure. It should not be performed unless mixture control unit is replaced or vehicle fails emissions testing. On 960, idle mixture is not adjustable.

IDLE MIXTURE

1. Warm engine to normal operating temperature. Check idle speed and ignition timing. Disconnect oxygen sensor. Check CO level. See «IDLE SPEED & CO LEVEL»(/volvo/960/i-1990-1994/remont/adjustments/#engine-controls-adjustments) table.
2. If CO level is incorrect, turn off engine. Drill two 5/16" holes in adjustment plug. Pull out plug using snap ring pliers. Start engine, and adjust CO level.
3. Turning screw counterclockwise decreases CO level. (Scheme 2) Turning screw clockwise increases level. When adjustment is completed, reconnect oxygen sensor lead and remove test equipment. Seal idle mixture screw using a new plug.

Scheme 2

THROTTLE SWITCH

Note. Throttle switch adjustment procedure for 960 is not available.

Checking

Open throttle slightly and listen for a click. Click indicates throttle switch opens.

Adjusting

Ensure throttle valve is closed. Loosen TPS retaining screws. Turn TPS switch clockwise slightly. Turn TPS switch back again until a click is heard. Tighten retaining screws. Recheck setting. Open throttle slightly, a click should be heard. Click indicates switch is activating.

240, 740 & 940

Install a.004" (.10 mm) feeler gauge between throttle pulley and idle stop. (Scheme 3) Ensure distance between throttle lever and adjustment screw is.004" (.10 mm). If measurement is not within specification, adjust link rod.

Scheme 3

Throttle pulley should contact idle stop in idle position. Cable should be taut but not affect position of throttle pulley. At full throttle, pulley should contact full throttle stop. Adjust throttle cable as required if it is out of adjustment. (Scheme 3)

960

Throttle pulley should move freely without sticking. Cable should be taut in idling position, without altering pulley position. Pulley should rest against idle stop. (Scheme 4) Adjust cable as necessary. Press accelerator pedal to floor, and ensure pulley reaches full-load stop.

Scheme 4

KICKDOWN CABLE

Note. Depress accelerator pedal. DO NOT turn throttle pulley by hand or adjustment will be incorrect.

On 240, 740 and 940, fully depress accelerator pedal. At full throttle, distance between cable stop and cable casing should be 1.98-2.07" (50.4-52.6 mm). (Scheme 5) On 960, adjust cable until it is just pulled gently tight. Adjust kickdown cable if it is not within specification.

Scheme 5

BASIC THROTTLE SETTING

Note. If basic throttle setting is adjusted, throttle position will change. Therefore, throttle switch must be adjusted whenever basic throttle setting is adjusted. See THROTTLE SWITCH under THROTTLE CONTROLS . Basic throttle setting for 960 is not available.

Loosen basic throttle setting adjustment screw lock nut. (Scheme 6) Turn screw until throttle is completely closed. Tighten adjustment screw until it touches throttle lever and then turn an additional 1/4 turn. Tighten lock nut, making sure not to change adjustment. Recheck basic throttle setting.

Scheme 6

See also:
• IDLE SPEED & CO LEVEL