F

It is important to switch off fan motor and a c compressor during adjustments. Use separate tachometer from tester or similar. 7. Check CO setting. If value is not as specified, remove mixture control unit and take steel ball out of bore providing access to mixture regulating screw. See page 25 - 28. 8. Insert adjusting wrench P 377. a) Always make CO adjustments from lean to rich. For example, if the mixture is too rich, first turn mixture regulating screw counterclockwise further than...

Checking System Pressure

Air Auxiliary Porsche 924

Pull electric connectors off of control pressure regulator and auxiliary air regulator, so that these parts will not heat up during subsequent test. The fuel supply, electric fuel pump and fuel filter must be in perfect condition for this test. 2. Pull fuel pump relay off of relay plate. 1. Move change-over valve to position 3. 1. Move change-over valve to position 3. 3. Bridge terminals 30 and 87 with a piece of wire. Fuel pump should run. 2. Disconnect electrical connector at air flow sensor...

Removing And Installing Radiator

Remove expansion tank with bracket and hoses. 6 On cars with air injection also remove air cleaner housing with holder. 2. Remove expansion tank cap. C aution Pressurized cooling system. If engine is warm, turn cap to first notch and let excessive pressure escape. Then unscrew cap completely. 5. Remove expansion tank with bracket and hoses. 6 On cars with air injection also remove air cleaner housing with holder. 4. Drain coolant at plug on radiator, If all coolant is to be drained, open heater...

Checking Location Of Adjusting Screw Caution

After adjusting valve clearance be sure that edge of tappet is in line with green area of US 8005. Camshaft must be removed to replace valve adjusting screws. The following adjusting screws are available Note After screws identified with paint are used up only screws with notch marks will be supplied. The adjusting screw (part no. 046 109 453 C) however, will still be supplied without any identification (formerly dot of white paint). New adjusting Identification Old adjusting Identification

Info

From Mod. 81 0.5 to 1.0 (measured in front of cat. conv.) HIGH ALTITUDE ADJUSTMENT ON ENGINE XE - MODEL 7 7 1 2 Air pump control must be modified as follows for operation of car in high altitude states. 1. Disconnect wire (arrow) at temperature switch. 2. Attach disconnected wire to vacant terminal of second wire (arrow). This prevents operation of temperature switch. ADJUSTING IDLE SPEED CO 1980 Models 2. Connect exhaust gas test line to test connection of catalytic converter. 1. Pull off...

Removing And Installing Auxiliary Air Regulator

Disconnect electrical connector at auxiliary air valve. 2. Loosen hose clamps and pull off hoses. 3. Loosen Allen head bolts and remove auxiliary air regulator. CHECKING AUXILIARY AIR REGULATOR Cold Engine 1. Detach hose at auxiliary air regulator. 4. Turn on ignition. Air passage must be closed after about 5 min. 2. Check visually that air passage is open. (Use a mirror and flashlight, if necessary) 3. Disconnect electrical connector at air flow sensor. Removing and Installing Auxiliary Air...

Disassembly And Assembly Notes

Top installation holes for manual transmission. Bottom installation holes for automatic transmission (marked with A '). LAYOUT OF EMISSION CONTROL SYSTEM (From Model 77 1 2) 3 - Temperature valve for EGR 4 - Exhaust gas recirculation (EGR) valve 5 - Two-way valve for air injection - California only 7 - Diverter valve - California only 8 - Throttle valve housing 10 - Deceleration valve - Manual Transmission only Temperature switch is closed, two-way valve is energized. Vacuum connections 1 (blue...

Checking Entire Fuel System For Leaks

Check on a warm engine, but not immediately after engine was run hot. 2. Turn on ignition. Detach plug on air flow sensor contact. Fuel pump (s) run. The fuel pump(s) in cars from 1979 models can be run by supplying battery voltage to multiple-pin plug terminal 7 (red white) with a piece of wire. The ignition need not be turned on. 5. Stop by turning valve to position 3 and measure delivery rate. Test value 160 to 240 cc minute. Check on a warm engine, but not immediately after engine was run...

Removing And Installing

Detach electrical connector at fan motor harness arrow and remove clip. For cars with a front stabilizer the fan must be taken off of the fan ring while still in the car. 1. Detach electrical connector at fan motor harness arrow and remove clip. For cars with a front stabilizer the fan must be taken off of the fan ring while still in the car. 4. Install the fan so that the water drain hole in the fan motor faces down. Position wire harness properly. After installation check fan's direction...

Dangers Of Electronic Ignition Systems

The 924 is equipped with an electronic ignition system. The ignition output of this transistorized ignition coil ignition system is so high, that with the engine running there could be dangerous current in the system. Consequently, any work on the ignition system requires that the ignition be turned off or the battery ground cable disconnected. Such jobs would include the following 1. Connecting engine testing equipment timing light, tachometer, ignition oscilloscope etc. . 2. Replacement of...

Removing And Installing Distributor Drive Gear

Pull off drive gear with a standard puller. 1. Align drive gear so that center of a tooth is in line with opposite groove. 2. Knock on drive gear cold against stop with a suitable pressure pad. Removing and Installing Valve Springs Machining Intake Valves Dimension a should never be larger than 3.5 mm,

Removing And Installing Camshaft

B18b1 Camshaft Bearing Cap Guid

Remove camshaft lubrication tube replace nuts A hand tight When installing bearing caps note off-center position of bore. First place caps in position to check the proper installation position. 1. Tighten bearing caps 2 and 4 crosswise alternately. 3. Install camshaft lubrication tube this requires loosening again nuts A on bearing caps 2 and 4 . 3. Loosen bearing caps 2 and 4 crosswise alternately.

Checking Fuel Pump Delivery Rate

Fuel Tank Lines Small Engines

Clamp fuel return line at fuel tank with standard hose clamp. 3. Hold end of return line in measuring container size about 1500 cc . 2. Disconnect fuel return line between fuel distributor and fuel tank at threaded connection. The new version with fuel line is shorter so that cowl must be removed from mixture control unit for testing. 2. Disconnect fuel return line between fuel distributor and fuel tank at threaded connection. The new version with fuel line is shorter so that cowl must be...

J

Remove exhaust gas recirculation line arrows 31. Attach chain US 1105 to lift points on engine. Using universal floor crane, lift engine slightly to tension chain. 33. Remove entire left hand engine mount as seen in driving direction . Loosen lower right hand engine mount. 34. Lift engine out carefully by lifting and turning at same time.

Caution

A Always make CO adjustments from lean to rich. For example, if the mixture is too rich, first turn the CO adjusting screw counterclockwise further than necessary and then clockwise to specified setting. b Never press down on adjusting wrench during adjustments engine will stall . c Turn the CO adjusting screw only slightly, since the smallest turn will change the CO level considerably. d Make adjustments as quickly as possible to prevent intake ports from becoming too hot. 8. Turn clockwise...

Removing And Installing Diverter Valve

Loosen vacuum hose, hose clamps and socket head screws, and remove valve. 26-6 Removing and installing diverter valve Checking check valve CHECKING OPERATION OF CATALYTIC CONVERTER California only 2. Connect CO-tester according to manufacturer's instructions. Test values Before catalytic converter at probe connection CO max. 0.7 After catalytic converter at tail pipe CO max. 0.4 2. Connect CO-tester according to manufacturer's instructions. Connect exhaust gas analyzer probe to test connection...

Checking Fuel Delivery Rate For Control Pressure Circuit

Pressure Fuel P378 Porsche 924

Disconnect left hose from special tool P 378 at feed line to control pressure regulator and hold in a measuring glass capacity at least 500 cc . 4. Turn on ignition. Turn valve to position 2 and let fuel pumps s run exactly 1 minute by pulling off two-pin plug on mixture control unit. The fuel pump s in cars from 1979 models can be run by supplying battery voltage to multiple-pin plug terminal 7 red white with a piece of wire. The ignition need not be turned on. 3. Disconnect left hose from...

Installing Drive Belt

Camshaft And Crankshaft

Crankshaft position engine installed TDC mark on flywheel and clutch housing must align with each other. Printed in Germany - VII, 1980 Installing Drive Belt 15-5 Mark on camshaft sprocket and indicator on cylinder head cover must align with each other. Turn tensioning roller in direction of arrow. It must be just barely possible to twist the drive belt 90 when holding belt at a point midway between the camshaft and crankshaft sprocket with thumb and index finger. Crankshaft position engine...

Unit For Oxygen Sensor

An elapsed mileage switch for the oxygen sensor is installed on the left engine carrier. After a distance of 30,000 miles it will turn the oxygen sensor indicator light ON. Each time the oxygen sensor is replaced, the elapsed mileage switch must be reset to zero. Loosen three screws on control unit. Pull off plugs and remove control unit. 2. Press in reset button of elapsed mileage switch against the stop with a piece of approx. 3 mm dia. wire. This will reset the counter to zero and restore...

Checking Frequency Valve For Oxygen Sensor Control

924 Porsche Wiring Pictures Alternator

Connect ohmmeter on frequency valve. 2. Connect ohmmeter on frequency valve. 2. Loosen coupling nut arrow on frequency valve, while counterholding on hexagon of fuel feed line. 1. Loosen fuel return line on solenoid and bracket for frequency valve. 3. Replace frequency valve if necessary.

Removing And Installing Crankshaft Oil Seal

Remove pulley end oil seal with 10-221 or screwdriver Install pulley end oil seal. Press in to stop. Removing and Installing Crankshaft Oil Seal 13-9 UNDERSIZE CRANKSHAFTS FOR REPAIRS Dimensions in mm Crankshaft main Crankshaft connecting Size Diameter Out of round Diameter Out of round

Replacing Check Valve

Endwrench Porsche 924

Important Conform with safety regulations when Important Make sure fuel hose is positioned correct- working on fuel system ly and cannot rub prior to tightening 3. Remove hose clamp and check for leaks. Install guard again. 1. Clamp fuel feed hose with standard hose clamp and detach pressure side hose on fuel pump by loosening hollow union bolt or coupling nut. 2. Loosen check valve, while counterholding on hexagon of fuel pump with a narrow machined open-end wrench. 1. Screw in new check valve...

Checking Warm Up Regulator Warm Engine

Warm Regulator Porsche 924

Disconnect wire connectors at warm-up regulator. 2. Disconnect electrical connector at air flow sensor. Turn on ignition. 3. Check power supply with voltmeter at disconnected plug. Voltage min. 11.5 V. Printed in Germany Removing and Installing Warm-Up 25 - 21 Regulator - Checking Warm-Up Regulator 4. Check heating coil, resistance of heating coil approx. 20 Ohm. If heating coil has open circuit, replace warm-up regulator.

Checking Crankshaft Bearing Play

Gauge 004 010 Plastigage Type

The Plastigage method is a simple way of checking bearing play - even with crankshaft installed in car. Plastigage is available in three different sizes for measuring ranges from 0.025 to 0.23 mm 0.0001 - 0.009 in. PG-1 green 0.025 to 0.075 mm 0.001-0.003 in. PR-1 red 0.05 to 0.15 mm 0.002-0.006 in. PB-1 blue 0.10 to 0.23 mm 0.004-0.009 in. The end play is measured on bearing 3 thrust bearing with a feeler gage. Play of new bearings 0.10 to 0.19 mm Wear limit 0.25 mm 2. Clean bearing shell and...

Removing And Installing Oxygen Sensor

Unscrew oxygen sensor. 2. Pull off rubber cap from oxygen sensor plug and plug. 1. Coat threads of oxygen sensor with Bosch paste VW 140 16 Ft. Be careful that paste does not enter slot of sensor. 2. Tighten sensor to specified torque. Reference value 50 to 60 Nm 36 to 43 ft lb . 3. Pull off plug from oxygen sensor.

Porsche 911 Battery Voltage At Terminal 15 To Ground

Porsche 924 Coil Ground

Check distributor cap, distributor rotor, ignition lines and spark plugs Warning ignition off . Resistance of spark plug wire including connector approximately 6 k Ohm Resistance of distributor rotor approx. 5 k Ohm 3. Check ignition timing Timing good 5. Check ballast resistors and ignition coil Ignition off, wires disconnected at resistors and ignition coil Ballast resistor 0.4 Ohm 0.35 to 0.45 Ohm Ballast resistor 0.6 Ohm 0.55 to 0.65 Ohm Ignition coil primary between terminals 1 and 15...

Removing And Installing Distributor

When installing the distributor rotor make sure that it faces the cylinder 1 mark on the distributor housing. 2. Remove distributor cap, disconnect vacuum hose and wires, unscrew distributor hexagon nuts and remove distributor. 3. When installing the distributor rotor make sure that it faces the cylinder 1 mark on the distributor housing.

Removing And Installing Voltage Regulator

Pull hose off connector on alternator guard. 4. Remove guard after unscrewing the three hexagon head screws. 6. Be careful of ground strap when installing guard. 6. Be careful of ground strap when installing guard. 2. Pull hose off connector on alternator guard. 4. Remove guard after unscrewing the three hexagon head screws.

Removing And Installing Fuel Tank

Remove luggage compartment lining, 2. Remove final muffler and transmission. 5. Remove cover in luggage compartment, 3. Drain fuel clamp return hose with standard hose clamp. Detach suction hose at fuel pump and drain fuel into an appropriate container. 6. Disconnect wires at tank sending unit, Removing and Installing Fuel Level Transmitter 20-7 Removing and Installing Fuel Tank 9. Detach fuel hoses and remove fuel tank from below. 1. When installing, slide the protruding hoses into the tank...

Removing And Installing Cylinder Head

The cylinder head can be taken off without removing the engine. The engine block has 2 centering bushings to facilitate installation of head. REMOVING AND INSTALLING CYLINDER HEAD from 19 80 Model Polygon socket head bolts for cylinder head. See figure for tightening sequence, Opposite sequence for loosening. warm 120 Nm 86 ft lb cold 100 Nm 72 ft lb If the cylinder head was removed, the cylinder head bolts must be retorqued after about 1000 miles 1600 km. Warm up engine. Using loosening...

Specs For Ignition Coil On 924s

1977 Porsche 924 Coil Wiring Diagram

Observe the following safety measures to avoid damage The high voltage lead must be fitted with a shield-while working on TCI-H ignition systems. ing sleeve of at least 2 k-ohms. 1. Only connect and disconnect testers and leads with ignition turned off. 2. Spring retainers of removed distributor and dust caps must not hang in sensor system while cranking engine. 3. Never connect a capacitor on the ignition coil. 4. Specified ignition coil must not be replaced with a conventional ignition coil....

Checking Operation Of Deceleration Valve

Porsche 924 Cold Start Valve

Detach hose between valve and intake manifold at valve and insert plug in open hose end. 2. Start engine. Bring engine briefly to about 350 rpm. Shut throttle valve quickly. 3. Check with finger for suction at hose connection. Replace valve if suction cannot be felt. Checking Cold Start Valve for Leaks Removing and installing deceleration valve Checking operation of deceleration valve

Removing And Installing Mixture Control Unit

Porsche 924 Distributor

Always use new seals for fuel connections. 2. Remove rubber boot from air sensor. 3. Clean fuel distributor thoroughly in area of fuel connections. 4. Detach wire plugs, injection lines, control pressure line, fuel return line and fuel feed line. 5. Loosen 6 Allen head bolts and remove mixture control unit. Removing and Installing Mixture Control Unit

Basic Adjustment Of Mixture Control Unit Initial Start

Porsche 924 Adjust Idle Speed

This test requires that the sensor plate be adjusted correctly rest position . 1. Unscrew one injection line on fuel distributor. 2. Bridge electrical safety circuit. 3. Turn mixture control screw slowly, without applying pressure on adjusting wrench P 377, until fuel just begins to leave the open outlet arrow of the fuel distributor. From this position turn mixture control screw counterclockwise one half turn. 4. Connect injection line again. Run engine to operating temperature approx. 80 C...

Checking Cold Start Valve For Leaks

Disconnect electrical connector at air flow sensor pump running . 3. Wipe jet of start valve dry. This jet must not leak at all within a minute's time. Replace a malfunctioning or leaky start valve. CHECKING OPERATION OF HOT START VALVE Reduction of Control Pressure During Hot Start Warm engine. Coolant temperature 60 C 140 F or more. 1. Connect pressure tester and set switching valve at position 2. 2. Operate starter to open hot start valve and drop control pressure. Specification 0. 5 to...

Checking Valve Guides

Porsche 914 Install Engine Seal

When reworking valves seats valve guides must be checked for wear. This is particularly true for engines with high mileage. If wear is excessive, cylinder head must be replaced, until such time when repair procedures are published. 2. Place new valve in guide. End of valve stem must be flush with guide. Intake valve guide max. 0.8 mm Exhaust valve guide max. 1.0 mm REMOVING AND INSTALLING VALVE STEM SEAL Cylinder Head Installed 1. Remove camshaft and tappets. 3. Move piston of each cylinder to...

Basic Adjustment Of Mixture Control Screw After Replacement Of Pivot Lever

This test requires that the sensor plate be adjusted correctly rest position . 2. Bleed fuel system , Remove injectors and hold over a container, operate sensor plate by hand several times . 3. Using adjusting wrench P 377 first turn mixture control screw counterclockwise by 1 - 2 turns. Never apply any pressure on the adjusting wrench during adjustments, since this would change the injection rate. 6. Run engine to operating temperature 80 to 90 C 180-190 F oil temperature, and adjust idle...

Replacing Valve Guides

During repairs, installed valve guides must have the same codes as those replaced. 3. Select suitable replacement repair guide from following table. Cylinder heads with cracks between valve seats or between a valve seat and spark plug threads can still be used without risk of a shorter service life, if the cracks are not wider than 0. 5 mm max. or if only the first spark plug threads are damaged. Code for Production and Repair Guides 1. Clean and inspect cylinder head. Heads, in which the valve...

Machining Valve Seats

Valve Seats

Valve seats showing traces of wear or burnt spots can be machined until reaching wear limit depth b. If depth b is exceeded the cylinder head must be replaced, since valve clearance could no longer be adjusted to specifications. Valve seat inserts cannot be replaced with normal worshop facilities. If a valve seat has been machined, the valve adjusting screw must be replaced with adjusting screw 046 109 453 C previously with white marking, now with no marking . a - 36.5, 38.5 mm dia. a -...

Removing And Installing Engine

Porsche 944 Air Duct Alternator

Detach windshield washer hose at T-adaptor, 7. Disconnect electrical connector of engine compartment light. 4. Set heater control lever to warm position fully open and remove pressure cap. 5. Drain coolant at plug on radiator, and loosen and remove coolant hoses. 9. Remove coolant expansion tank with carrier and hoses. 10. Take windshield washer tank off and place it behind right-hand headlight. 11. Take alternator cooling hose off. 12. Disconnect starter wire arrow at positive pole,...

Removing And Installing Needle Bearing

Needle bearing can be replaced without removal of engine. Clutch must be removed first. See Repair Manual - Group 30. Pull out needle bearing with Special Tool 10-202. 13-12 Removing and Installing Flywheel Replacing Starter Ring Gear Pull out bearing sleeve with US 1088. Pull out bearing sleeve with M 12 x 65 hexagon head bolt. Drive in needle bearing up to stop with Special Tool 9124. For version II drive in seal up to stop with Special Tool 9123. Use about 3 grams of lithium grease NLGI...

Checking Oil Pressure And Oil Pressure Switch

Remove oil pressure switch and install tester. 2. Install tester in cylinder head in place of the oil pressure switch connect test lamp to oil pressure switch terminal Wk and ignition coil terminal 15. Turn ignition on test lamp should light. If not, replace the switch. 3. Start engine test lamp must go out. Stop engine. Lamp must light again at a pressure between 0.3 and 0.6 bar 4.3 and 8.5 psi . 4. Start engine. The oil pressure must be at least 2 bar 28 psi at 2000 rpm and oil temperature...

Tolerances And Wear Limits

80- 93 C or 85 - 102O C 176 - 200 F or 185 - 216 F 0.9-1.15 bar 12. 8-16.4 psi 0. 06 - 0.1 bar 0.9 - 1.4 psi 0. 03 - 0. 07 mm 0. 001 - 0. 002 in. 0 - 0.13 mm 0 - 0. 005 in. 2. 2 - 3. 2 bar 31. 3 - 42. 6 psi 0. 3 - 0. 6 bar 4. 3-8.5 psi V alve Timing Camshaft bore Camshaft Camshaft Camshaft 26. 00 - 26. 021 mm 1. 0236 - 1. 0245 in. 25.94 - 25.96 mm 1. 0213 - 1. 0181 in. 0. 05 - 0. 16 mm 0. 002 - 0. 006 in. measured at center brg. brgs 1 5 on V-blocks 38. 5 - 38. 525 mm 1.515 - 1.517 in. 38.45 -...