Volvo 850 engine adjustments service manual
Volvo 850 service & repair manual
1995 Volvo 850
1995 ENGINE PERFORMANCE
Volvo 850 – On-Vehicle Adjustments
Warm engine to normal operating temperature. Disconnect single wire from negative terminal of ignition coil(s). Check compression with all spark plugs removed, throttle valve wide open and at normal cranking speed (250-300 RPM).
CAUTION: Failure to disconnect ignition coil negative terminal may cause damage to ignition system control unit(s).
COMPRESSION SPECIFICATIONS TABLE
Compression Ratio …………………………… 10.5:1
NOTE: Hydraulic lifters used. No adjustment is required.
Ignition timing is computer-controlled and is not adjustable. IGNITION TIMING TABLE (Degrees BTDC @ RPM)
Application (1) Timing Non-Turbo ………………………………… 10 @ 800 (1) – Ignition timing is computer-controlled. Not adjustable.
IDLE SPEED & MIXTURE
NOTE: Cold (fast) idle is computer-controlled. Basic idle speed is not adjustable.
IDLE SPEED & CO LEVEL
NOTE: Idle mixture is not adjustable. IDLE SPEED & CO LEVEL TABLE
Application Idle RPM (1) CO Level
Cooling Fan On ………….. 800 …………… 0.6% Cooling Fan Off …………. 825 …………… 0.6%
(1) – CO level is measured before catalytic converter.
Open throttle slightly and listen for a click. Click indicates throttle switch opens.
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.
THROTTLE LINK ROD
1) Mount link rod on throttle housing with “L” mark on rod at housing end and “R” mark on pulley end. Put a .10″ (2.5 mm) feeler gauge at pulley stop. See Fig. 1. Turn middle of rod until clearance between lever and adjusting screw is .012″ (.30 mm). Ensure rod does not turn and tighten lock nuts.
2) Recheck clearance. Ensure a .020″ (.50 mm) feeler gauge cannot be inserted between lever and adjusting screw. Ensure a .004″ (.10 mm) feeler gauge can be inserted between lever and adjusting screw. If clearance is not correct, repeat step 1).
Fig. 1: Adjusting Throttle Link Rod
Courtesy of Volvo Cars of North America.
Throttle pulley should move freely without sticking. Cable should be taut in idling position, without altering pulley position. Pulley should rest against idle stop. See Fig. 2. Adjust cable as necessary. Press accelerator pedal to floor and ensure pulley reaches full-load stop.
Fig. 2: Adjusting Throttle Cable (Typical) Courtesy of Volvo Cars of North America.
BASIC THROTTLE SETTING
NOTE: If basic throttle setting adjusted, throttle position will change. Therefore, throttle switch must be adjusted whenever basic throttle setting is adjusted. See THROTTLE SWITCH under THROTTLE CONTROLS.
Loosen basic throttle setting adjustment screw lock nut. See Fig. 3. Turn screw until throttle is completely closed. Tighten adjustment screw until it touches throttle lever and then turn an additional 1/2 turn. Tighten lock nut, making sure not to change adjustment. Recheck basic throttle setting.
Fig. 3: Adjusting Basic Throttle Setting (Typical) Courtesy of Volvo Cars of North America.
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