Porsche 944 Workshop Manual
  1. Manuals
  2. Brands
  3. Porsche Manuals
  4. Automobile
  5. 944
  6. Workshop manual

Porsche 944 Workshop Manual

Porsche automobile workshop manual
Hide thumbs Also See for 944:
Table of Contents

Advertisement

Quick Links

See also: Driver Manual , Workshop Manual
Workshop Manuel
Volume IA - Engine, 16 valves
DR. ING. h. c. F. PORSCHE Aktiengesellschaft
As webpage by http://www.9ss1.dk/porsche944

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the 944 and is the answer not in the manual?

Questions and answers

ray kutner
April 22, 2025

spark plug for 1983 porsche 944

0

Related Manuals for Porsche 944

Summary of Contents for Porsche 944

  • Page 1 Workshop Manuel Volume IA - Engine, 16 valves DR. ING. h. c. F. PORSCHE Aktiengesellschaft As webpage by http://www.9ss1.dk/porsche944...
  • Page 2 General Technical data Maintenance, Self-diagnosis Fault diagnosis, DEE control unit Connecting into the vehicle - 944S Starting fault diagnosis Functional test - actuator and input signal List of test codes System adaptation Knock detection Troubleshooting List of fault codes Clearing fault memory Operating conditions for start of diagnosis Operating instructions for System Tester 9288 Engine, Crankcase...

  • Page 3: Table Of Contents

    DEE control unit coding - 944 S, Model 87 onward Replacing spark plugs Equipment table, Model 89 onward DEE control unit coding - 944 S 2, Model 89 onward DME-Diagnosing / Troubleshooting Table of contents Printed in Germany - XXIV, 1991...

  • Page 4: Technical Data

    General TYPE 944 S (16-VALVE ENGINES) - '87 MODELS ONWARD Printed in Germany - XIII, 1987 Technical Data...
  • Page 5 General TECHNICAL DATA (Adjustment specifications and wear data are stated in the appropriate Repair Groups) Note: US values are stated in parentheses DRIVE UNIT Internal engine designation Number of cylinders Bore Stroke Displacement (actual) Compression ratio Max. engine output to 80/1269/EC Net power, SAE J 1349 at engine speed...
  • Page 6 Crankcase Crankshaft Crankshaft bearings Connecting rods Connecting rod-bearings Pistons Balance shafts Balance-shaft bearings Cylinders Cylinder head Valve guide Valve arrangement Valve timing Camshaft Camshaft drive Balance-shaft drive Valve clearance Timing Printed in Germany - XIII, 1987 Two-part light alloy crankcase Forged, 5 bearings Plain Cast, opt.
  • Page 7 General ENGINE COOLING ENGINE LUBRICATION Lubrication Oil pressure Oil-pressure indicator Max. oil temperature Oil consumption EXHAUST SYSTEM EMISSION CONTROL HEATING 0.12 Technical Data Sealed cooling system, electric fan with thermoswitch, antifreeze effective to - 25° C Forced-feed lubrication with sickle-type pump, oil filter and oil-water heat exchanger in main oil flow and secondary water flow integrated in crankcase...
  • Page 8 FUEL SYSTEM Injection Fuel delivery Fuel octane rating Fuel consumption to 80/1268/EC or ECE R 15/04 Constant 90 km/h Constant 120 km/h EC exhaust urban cycle ELECTRICAL SYSTEM Suppression Battery voltage Battery capacity Alternator (output) Ignition Firing sequence Ignition timing Printed in Germany - XIII, 1987 Digital Motor Electronics 1 electric fuel pump...
  • Page 9 General BODY DESIGNS DIMENSIONS (at DIN curb weight) Length Length with opt. extra US bumpers Width Height Wheel base (in design pos.) Track: Front Rear Ground clearance (at per. total weight) Bed clearance (at per. total weight) Overhang angles: Front Rear 0.14 Technical Data...
  • Page 10 Max. car/ kg/lbs trailer weight kg/lbs Max. drawbar load kg/lbs kg/lbs Per. roof load kg/lbs With genuine Porsche roof kg/lbs transport system Printed in Germany - XIII, 1987 - to DIN 700 20 - Standard Sports package 640/1411 630/1389 (650/1433)
  • Page 11 General CAPACITIES Engine (measurement with dipstick as per Driver's Manual is definitive) Engine oil Engine coolant Transmission with differential Fuel tank Brake-fluid reservoir Windshield and headlight washing fluid reservoir PERFORMANCE Maximum speed Acceleration from 0-100 km/h* (0-60 mph)* (1/4 mile from standing start)* Kilometer from standing start*...
  • Page 12 Technical data - Type 944 52 - Model 89 (Values for adjustment and wear are to be found in the respective repair groups) Notes: USA values are given in brackets Drive unit Internal engine designation Bore Stroke Displacement (actual) Displacement (rounded down) Compression ratio Max.
  • Page 13 DME control unit error diagnosis 944 S as from 88 model As from model year 88, the DME control unit 944 S is capable of a self-diagnosis. That is to say, the control unit is capable of detecting, storing and displaying system errors. The con- trol unit capable of diagnosis is identified by an altered part number.
  • Page 14 Display LED off Flashing LED LED on 03 - 2 Maintenance, Self-diagnosis Test sequence terminated / igniti Error code / test code Ignition on DME control unit error diagnosis Printed in Germany - XVI, 1987...
  • Page 15 Connection in the 944 S In the 944 S, the diagnosis socket is attached to a separate cable harness located above DME control unit. Ignition off After connecting the tester, the following dis- play must appear. Display: If this is not the case, check the tester ter-...
  • Page 16 Round plug Pin 4 Pin 1 Pin 7 Pin 6 The ignition must not be switched off Pin 2 during the entire error diagnosis procedure. Pin 5 Pin 3 Connection in the 944 S Printed in Germany - XVI, 1987...
  • Page 17 Starting error diagnosis Condition: Engine off Ignition on Display: Press the green key until the clear symbol appears on the function display. Display: The diagnosis sequence for the DME control unit then takes place. Starting error diagnosis Printed in Germany - XVI, 1987 Maintenance, Self-diagnosis If an error is displayed - take the note of the error (e.g.
  • Page 18 Press the green key until the clear symbol ap- pears on the function display. The following display must then appear. Display: This now terminates diagnosis of the DME control unit. If one or several errors (up to 5) has/have been displayed, the error memory must be reset;...

  • Page 19: Function Check

    Actuator and input signal function checking An actuator and input signal function check can be carried out independently of an error diagnosis. This function check tests individual components or electrical signals with respect to their functioning or signal paths. Functions ara triggered from the diagnosis tester.
  • Page 20 Press the green key until the ctear symbol pears on the function display. This activates the first testing step and the injection valves are activated. Display: The injection valves must all operate audibly or tangibly. Note: If later attempts are made to start the engine, starting difficulties may occur because a slight residual amount of fuet is injected during this...
  • Page 21 As from the "idle contact" testing step, specific controls must additionally be operated on the car for the purpose of function checking. Idle contact display: Slightly press the accelerator. The LED must go off after approx. 20 mm and the display will appear After approx.
  • Page 22 Initiale the air-conditioning control terminal testing step. Display: Switch on the air-conditioning system. The LED must go off and the display will appear after approx. 3 s. Display: If this is not the case, an error has occurred the area of the air-conditioning system's wiring.
  • Page 23 Press the green key until the clear symbol appears. Display: End of the actuator and input signal function checks. Actuator and input signal function checking Printed in Germany - XVI, 1987 Maintenance, Self-diagnosis 03 - 11...
  • Page 24 03 - 12 Blank page...
  • Page 25 Test code list Test code Components 1311 1321 1322 1332 1333 1334 1335 Test code list Printed in Germany - XVI, 1987 Maintenance, Self-diagnosis Injection valves Rotary idle controller Solenoid valve - tank bleeding Idle contact Full load contact Air-conditioning/AC switch Air-conditioning/compressor coupling 03 - 13...
  • Page 26 03 - 14 Blank page...
  • Page 27 System adaption System adaption can be carried out with the tester. That is to say. the electronic idle control in the DME control unit is adapted to the actual air throughput and to the current condition of the engine. Note: For system adaption, it is necessary for the engine to be at operating temperature.
  • Page 28 03 - 16 Blank Page...

  • Page 29: Knock Detection

    Knock detection Before knock detection is carried out, error diagnosis must first of all be performed to guarantee that no electrical error has occurred in the area of the knock control and the knock sensors. Knock detection should not be carried out if the customer has complained about poor out- put or too high a consumption, for instance.
  • Page 30 The tester is now active. If knocking occurs, this will be indicated by the tester, e.g.: Display: After the expiry of 10000 ignitions. the function display will change to "r". Display: Counting is now complete. The number af knocks is displayed in per mill.

  • Page 31: Troubleshooting

    Troubleshooting Diagnosis using the tester can refer only to the error path, but not to a defective component. Note: Before troubleshooting, the entire error memory must be read out. Troubleshooting Printed in Germany - XVI, 1987 Maintenance, Self-diagnosis Error code 1111 The supply voltage is too low <...
  • Page 32 Error code 1112 This error code indicates an error in the area of the idle contact. Possible error: Ground fault Switch stuck Testing the idle contact Extract the plug from the DME control unit. 03 - 20 Maintenance, Self-diagnosis Connect a ohmmeter between terminal 52 and terminal 24 on the DME plug.
  • Page 33 Error code 1113 This error code draws attention to an error in the area of the full load contact. Possible errors: Ground fault Switch stuck Testing the full load contact Connect an ohmmeter between terminal 53 and terminal 24 on the DME plug. Display: Throttle valve closed: Throttle valve in full load position: R <...
  • Page 34 Display 0° C = 4400 6800 15 - 30° C = 1400 3600 80° C = 100° C = If the values are not reached in this testing step, measurement must be carried out directly on the engine temperature sensor. The engine temperature sensor (NTC 2) in- forms the control unit about the current engine...
  • Page 35 Testing the power supply of the air-flow sensor: Ignition on On the extracted plug of the air-flow sensor, a voltage of 5 V +- 0,5 V must be measurable between terminal 3 (positive) and terminal 4 (negative) (if necessary, check by reference to the circuit diagram).
  • Page 36 Error code 1123 When this error code appears, the Lambda control has detected too rich ar too lean a mixture. Possible causes for too lean a mixture: Lambda probe ground fault Intiltrated air on the intake side Intiltrated air on the exhaust side of the Lambda probe Injection valve does not open Ignition cut-out...
  • Page 37 Measure the voltage between pin 1 and engine ground. The voltage is within the range of approx. 150 mV - 900 mV depending on the mixture composition. Check the cable harness to the DME control unit with reference to the circuit diagram. Troubleshooting Printed in Germany - XVI, 1987 Maintenance, Self-diagnosis...
  • Page 38 Error code 1131 This error code draws attention to an error in the area of knock sensor 1. 03 - 26 Maintenance, Self-diagnosis Error code 1132 This error code draws attention to an error in the area of knock sensor 2. 87/911 Error testing of the knock sensors is an active...
  • Page 39 Error code 1133 Error code 1133 draws attention to an error in the area of the knock control in the DME con- trol unit. If this error code appears, the control unit must be replaced. Troubleshooting Printed in Germany - XVI, 1987 Maintenance, Self-diagnosis Error code 1134 This error code draws attention to an error in...
  • Page 40 Testing the Hall generator's power supply Disconnect the Hall generator's connector. Ignition on A voltage of 12 Volt +- 1 V must be measurable between pin 1 (positive) and pin (negative). If this is not the case, check the wiring with reference to the circuit diagram. 03 - 28 Maintenance, Self-diagnosis Error code 1141...

  • Page 41: Table Of Contents

    Error code - List Error code 1500 1000 1111 1112 1113 1114 1121 1123 1124 1125 1131 1132 1133 1134 1141 A digit 2 (e.g. 1211) may appear in the second error code digit position to indicate "sporadic errors", i.e. an occasionally occurring error. This does not apply to error codes 1000 and 1500.
  • Page 42 03 - 30 Blank page...
  • Page 43 Resetting the error memory Once the DME control unit error diagnosis has been completed. this is completed by error code 1000. The error memory cannot be reset as follows until this error code appears: The yellow key must be pressed until the function symbol (see display) appears on the function display.
  • Page 44 Operating conditions for start of diagnosis Systems 944 S / 944 S2 Airbag Alarm system Webdesign from www.9ss1.dk/porsche944 03 - 32 Self-diagnosis Ignition on Engine standing still Operating conditions for start of diagnosis Engine running to n < 2000 rpm...
  • Page 45 Self-diagnosis Operating instructions for System Tester 9288 Operating instructions for System Tester 9288 03 - 33 Printed in Germany - XXIV, 1991...

  • Page 46: System Adaptation

    1. General information 1.1 Application The Systemtester 9288 (BOSCH KTS 301) is a microprocessor-con- trolled self-diagnosis tester. All systems which have a diagnosis interface as per ISO Standard can be tested with this tester. The following tests are possible: * Reading out the fault memory * Testing of the actuators * Testing the circuit inputs * System adaptation...
  • Page 47 - Accessory - Item 1 Charger with connecting cable, 1.5 m long Item 2 8-pin AMP plug 1.4 Vehicle-specific adapter cable Porsche No. 000 721 928.81 1.5 Connecting lead (Figure 4) - Self-fabrication - for printer, programme load station or similar unit.
  • Page 48 After pressing the key > , a selection menu is displayed: Menu 1 = Fault memory 2 = Drive links 3 = Input signals > < Menu 1 = System adaptation In the example - press key 1. There then follows the display of the number of errors which are stored (if any).
  • Page 49 Key 1 selects the next actuator (e. g. idle actuator). Following instruction: Repair fault accord- ing to repair instructions Continue: > After pressing key > , the following display appears: Injector to activate 1 = Start Continue: > Proceed with key 1 Can injectors be heard / felt? 1 = yes...
  • Page 50 Proceed with key 1 Prerequisite: Eng. at oper. temp. with all consumers and ignition off. Proceed with key > System adaptation 1 = Start Return: If key N is pressed = return to menu. If key 1 is pressed: Start engine ! Following engine start there appears: System is being adapted...
  • Page 51 BOSCH Part No. 1 687 335 002 1 684 483 152 1 684 485 170 1 680 552 005 1 684 465 193 1 684 465 194 4.1 Service parts (Porsche) Designation Porsche Part No. Systemtester 9288 000.721.928.80 Adapter cable 000.721.928.81 Battery charger 000.721.928.82...
  • Page 52 10 - 0100 Blank page...
  • Page 53 Tightening torques for engine (16-valve) Location Crankshaft/ crankcase Upper and lower crankcase sections (studs) Knock sensor Cylinder head Cylinder head to upper crankcase section Engine type M 44.40 Engine type M 44.41 (3.0 l) Camshaft bearing to cylinder head Allen screws for chain tensioner Banjo bolt / Chain tensioner...
  • Page 54 Tolerances and wear limits Engine M 44.40/41 Cooling system Coolant thermostat Cooling system cap Pressure valve Vacuum valve Oil circuit Oil consumption Oil pressure at 80° C oil temperature: at 5,000 rpm Oil capacity Difference of quantity between dipstick marks Valve timing Camshaft bore Camshaft...
  • Page 55 Tolerances and wear limits Engine M 44.40/41 Cylinder head with valves Mating surface Valve seat width Exhaust Seating angle Outer correction angle Inner correction angle Valve guides: Valve stem: Intake Exhaust Valve guide/valve stem Intake Exhaust Compression Pistons with connecting rods Cylinders/pistons Piston rings M 44/40 Piston rings M 44/41...
  • Page 56 Tolerances and wear limits Engine M 44.40/41 Con rod bush Piston pin Con rod bush/piston pin Crankshaft and cylinder block Crankshaft measure at bearing 2, 3 or 4 Bearing 1 and 5 on prisms Con rod journal Con rod/crankshaft Crankshaft beanng journal Crankshafts/ crankshaft Crankshaft bearing/...
  • Page 57 REMOVING AND INSTALlING ENGINE (16-VALVE ENGINES) TOOLS Description Engine suspension beam Note: If necessary, use a commercially available carabiner (load-bearing capacity 650 kg) to connect engine suspension beam to workshop crane. Printed in Germany - XIII, 1987 Engine/Crankcase Special Tool 3033 (VW Special Tool) Removing and Installing Engine...
  • Page 58 Engine/Crankcase REMOVING AND INSTALLING ENGINE (MANUAL TRANSMISSION) Remove by lowering engine from car. The bell housing remains attached to the engine. Removing 1. Align lifting platform pads beneath jacking points and raise car. 2. Place protective covers on fenders. 3. Unbolt and remove front wheels. 4.
  • Page 59 7. Disconnect breather hose for toothed helt cover at rear of lower section of air filter. Unbolt filter assembly as a unit and remove. 8. Remove air-flow sensor. 9. Slacken and remove ignition-distributor cap and rotor. (Mark installation position of rotor). Remove oil filter and ATF reservoir.
  • Page 60 Engine/Crankcase 12. Remove engine underguard. 13. Open coolant drain plug and catch coolant in a suitable container. Disconnect alternator breather hose. 14. Disconnect coolant hose at bottom right of radiator from engine and remove. Catch any coolant which may be left. 15.
  • Page 61 19. Detach Poly-rib belt tensioner from air-conditioning compressor and remove belt. Remove compresor from bracket and place to one side. (Do not disconnect refrigerant hoses). 20. Unbolt stabilizer with bracket from body and from control arms and remove. Disengage left and right tie rods.
  • Page 62 Engine/Crankcase 25. Disconnect leads from starting motor and remove starting motor. 26. Remove clutch actuating cylinder from bell housing. (Leave line connected). Unbolt and remove holder for line from upper crankcase half. 27. Disconnect exhaust from flange of exhaust manifold and disconnect exhaust extraction line.
  • Page 63 34. Pull engine forward, push rubber sleeve out of firewall toward engine compartment and carefully pull wire harness out of passenger-side footwell. 35. Separate engine from central tube/central shaft and lower from car. Installing Note the following: 1. Carefully feed wire harness for DME control unit, 8-pin connector and multi-pin connector into passenger-side footwell.
  • Page 64 Engine/Crankcase 7. Refill system with coolant and bleed system. 8. Fill reservoir with ATF and bleed steering system. 9. Run engine until it reaches operating temperature, check engine-oil level and coolant level, top up if necessary. 10 - 108 Removing and Installing Engine Printed in Germany...
  • Page 65 PISTONS. '87 MODELS ONWARD (16-VALVE ENGINES) Engine M 44.40 worldwide Compression: 10.9 : 1 Nominal dia. 100.00 mm An arrow pointing toward the belt pulley indicates the installation position. Printed in Germany - XIII, 1987 Engine/Crankshaft, Pistons Plain compression ring. chrome-plated Oil scraper ring Three-part oil wiper ring...

  • Page 66: Checking Pistons And Cylinder Bore

    Checking pistons and cylinder bores Motortype M 44.40 Repair Stage Piston Ø (mm) Fa. Kolbenschmidt Standard size 99.980 99.990 +- 0.007 100.000 Oversize 1 100.480 100.490 +-0,007 100.500 Checking pistons Measure approx. 61 mm from piston crown, 90° offset from piston pin axis. Note It recommended that the stocks of the relevant tolerance group are checked befare machining the cylinders.
  • Page 67 Pistons from Model 89 onwards Checking pistons and cylinder bore Engine type M 44.41 (3.0 l) Repair size Piston Ø (mm) MAHLE Standard 103.980 103.990 +- 0.007 104.000 Oversize 1 104.480 104.490 +- 0.007 104.500 Checking pistons Measure approx. 52 mm from crown of pis- ton, 90' offset to axis of piston bolt.
  • Page 68 This page are missing or blank in the book ! 13 - 104 Blank...
  • Page 69 Assemble cover of centrifugal oil compartment in upper crankcase section. Notes on installation Model 89 onward, Engine type M 44.41 (3.0 l) Note Under normal conditions. it is not necessary to remove the cover when overhauling an engine. If the cover is removed, however, the bolt area must be heated with a hot-air blower under all circumstances.
  • Page 70 15 - 100 Blank page...
  • Page 71 Engine/Cylinder This page are missing or blank in the book ! Printed in Germany Unknow page 15 - 101...
  • Page 72 Engine/Cylinder This page are missing or blank in the book ! 15 - 102 Unknow page Printed in Germany...
  • Page 73 Adjusting with dial gages 2. Align dial gage with improvised extension (205 mm long) on piston crown {cylinder 1). 3 mm pretension. Align second gage with hydraulic tappet of cylinder 1 intake valve. The dial gage must be aligned perpendicular to the intake valve.
  • Page 74 Engine/Cylinder Head, Valves 6. Turn the engine in the direction of rotation until piston reaches its upper limit af travel. 7. Set dial gage af cylinder 1 intake-valve hydraulic tappet to 0. 8. Turn crankshaft past ignition TDC (cylinder 1) while observing cylinder 1 intake-valve dial gage.
  • Page 75 Engine/Cylinder Head and Valve Drive Checking or adjusting camshaft setting for Model 89 onward Engine type M 44.41 (3.0 l) Note The timing has changed with installation of new camshafts for engine type M 44.41 (3.0 l) for Model 89 onward. Setting Inlet valve cylinder 1 Testing and adjusting value 0.75 +- 0.1 mm...
  • Page 76 Engine/Cylinder Head, Valve Drive Applying the TDC mark on the camshaft sprocket Engine type M 44.40 / 41 (3.0 l) Note Camshaft sprockets available from the spare parts department do not have a TDC mark. This TDC mark is applied after the camshaft timing has been set on the new engine.
  • Page 77 TOOLS - REMOVING AND INSTALLING CAMSHAFTS AND CYLINDER HEAD, DEGREES-OF-TURN METHOD OF TORQUING (16-VALVE ENGINES) Description Assembly bridges for installing camshafts Pressure piece for sealing ring Assembly drift for sealing ring Angle reader Printed in Germany - XIII, 1987 Engine/Cylinder Head, Valves Special Tool Remarks 9248...
  • Page 78 Engine/Cylinder Head, Valves REMOVING AND INSTALLING CAMSHAFTS AND CYLINDER HEAD Removing: 1. Align lifting-platform pads beneath jacking points and raise car. 2. Place protective covers on fenders. 3. Disconnect ground lead from battery 4. Disconnect breather hose for toothed-belt cover from rear of lower section of air filter.
  • Page 79 8. Disconnect vacuum hose, fuel-line-pressure damper and fuel-distribution pipe from intake manifold, disconnect plug from idle actuator, remove fuel rail with injection valves and place to one side. 9. Disconnect throttle-valve switch connector. Unbolt intake manifold from cylinder head and remove. 10.
  • Page 80 Engine/Cylinder Head, Valves 15. Relieve tension of camshaft toothed belt by slackening nut A and bolt B, pressing toothed-belt tensioner against the pressure of the spring with Special Tool 9200 and removing toothed belt from camshaft sprocket. 15 - 108 Removing and Installing Camshafts and Cylinder Head 16.
  • Page 81 Engine/Cylinder Head and Valve Drive 20. Remove bearing cover from cylinders 1 + 3. Hold both camshafts in the bearings with Special Tool 9226. Undo and remove front double bearing bridge and bearing cover. Note The rear double bearing bridge may remain on the cylinder head.
  • Page 82 Installing and tightening the cylinder head Model 87 onward Engine type M 44.40 Note The cylinder head may be mounted with the engine installed. 1. Place the cylinder head gasket in the cer- rect position. 2. Mount cylinder head Tightening sequence: Opposite to undoing sequence.
  • Page 83 Engine/Cylinder Head, Valve Drive Installing camshafts 1. Turn engine in direction of rotation by ap- prox. 45° before ignition TDC (cylinder 2. Lay intake shaft and exhaust camshaft in the timing chain. 3. Place both camshafts in the timing chain that the cast lugs are alignedwith the marked links of the chain.
  • Page 84 6. Apply Loctite 574 to the sealing surfaces of the front and rear double bearing bridges. 7. Use the assembly drift, Special Tool 9233 and pressure piece 9234 to drive the sealing ring into position at the drive end of the camshaft.
  • Page 85 Engine/Cylinder Head, Valve Drive Installing Camshaft Seal 1. Place sealing washers in bearings and install bearing bridge with Loctite 574. Tightening torque 20 Nm (15 ftlb). 2. After torquing the bearing bridge, install sealing cover with the aid af Special Tool 9234 Installing Camshafts Seal Printed in Germany - XVII, 1988...
  • Page 86 4° CS atter TDC 40° CS atter BDC 36° CS before BDC 4° CS before TDC Worldwide, Model 89 onward 944 S 2 M 44.41 (3,0 l) 944.105.277.07 944.105.275.09 277.07 275.09 3° CS atter TDC 47° CS atter BDC 39° CS before BDC 7°...
  • Page 87 REMOVING AND INSTALLING CHAIN TENSIONER Removing Remove hollow screws from cylinder head and chain tensioner and remove complete with oil line and seals. Note: Chain-tensioner plunger is spring-loaded. When removing, compress plunger and hold in this position with suitable retainer (improvised tool).
  • Page 88 This page are missing or blank in the book ! 15 - 114 Blank page...
  • Page 89 TOOLS - CYLINDER HEAD (16-VALVE ENGINES) Description Puller for valve stem seals Press-in tool for valve stem seals Valve spring assembly tool Printed in Germany - XIII, 1987 Engine/Cylinder Head, Valves Special Tool Remarks 9237 9225/1 9242 Or US 1020 + US 1020/1 Tools - Cylinder Head 15 - 115...
  • Page 90 Engine/Cylinder Head, Valves DISASSEMBLING AND ASSEMBLING CYLINDER HEAD (16-VALVE ENGINES) 15 - 116 Disassembling and Assembling Cylinder Head Printed in Germany...
  • Page 91 Description Hydraulic valve tappet Conical valve keeper Spring plate Valve spring Valve spring support Washer Valve stem seal Intake valve Exhaust valve Valve guide Printed in Germany - XIII, 1987 Engine/Cylinder Head, Valves Qty. Removing Withdraw with a magnet, do not mix up Note number Disassembling and Assembling Cylinder Head...
  • Page 92 Cylinder Head (16 Valves) Removing and installing valve springs Tools No. Description Assembly bridge Lever arm Magnetic removal head Assembly head Spacer Screws Note If the cylinder head is installed, the lever arm must be angled more accutely. 15 - 118 Engine/Cylinder Head, Valve Drive Special tool Remarks...
  • Page 93 Engine/Cylinder Head, Valve Drive Notes on assembly Remove and install the valve springs with the special tool supplied by Sauer 1. Mount the assembly bridge on the cylinder head. Secure the cylinderhead to the work bench with a screw clamp to prevent tilting.
  • Page 94 Remachining cylinder-head maling face Checking cylinder head for distortion Use a feeler gage an a straight edge or a precision straight edge to check the maling face of the cylinder head for distortion. Permissible maling-face uneveness: 0.05 Cylinder heads with distorted maling faces can be remachined and reused.
  • Page 95 NOTES ON ASSEMBLY REMOVING AND INSTALLING VALVE SPRINGS Cylinder head removed Remove and install valve springs with US 1020 + US 1020/1. REMOVING AND INSTALLING VALVE SPRINGS Cylinder head installed Remove and install valve springs with Special Tool 9242. Printed in Germany - XIII, 1987 Engine/Cylinder Head, Valves REMOVING VALVE STEM SEAL Remove valve stem seal with Special...
  • Page 96 Engine/Cylinder Head, Valves INSTALLING VALVE STEM SEAL Note: Always remember to place an 1 mm thick washer on the cylinder-head face before installing the valve stem seal. 15 - 122 Installing Valve Stem Seal 1. Lubricate valve stem and install shaft.
  • Page 97 Engine/Cylinder Head, Valve Drive Checking the valve guides 1. Clean the valve guides thoroughly. 2. Use a new valve to measure the tilt play. 3. Mount bar gate holder VW 387 on the cylinder head. The dial gaugemust be aligned parallel to the valve disk. Checking the valve guides Printed in Germany - XVII, 1988 4.
  • Page 98 15 - 124 Blank page...

  • Page 99: Replacing Valve Guides

    Engine/Cylinder Head, Valve Drive Replacing valve guides Tools Description Ejection base Plunger Plunger Reamer Replacing valve guides Printed in Germany - XVII, 1988 Special tool Remarks See drawing See drawing See drawing 3120 VW special tool 87/918 15 - 125...
  • Page 100 Drawing Plunger to press out the valve guide 15 - 126 Engine/Cylinder Head, Valve Drive Replacing valve guides Printed in Germany - XVII, 1988...
  • Page 101 Engine/Cylinder Head, Valve Drive Drawing Plunger to press out the valve guide Plunger to press in the valve guide Replacing valve guides 15 - 127 Printed in Germany - XVII, 1988...
  • Page 102 Replacing the valve guides 1. Clean and inspect the cylinder head. It is inexpedient to replace the valve guides cylinder heads where remachining is no longer possible on the valve seats or sealing areas. 2. Lay the cylinder head on the ejection base.
  • Page 103 Engine, Cylinder Head, Valve Drive 7. Ream the valve guides with Special Tool 3120 Proceed as follows: The valve guides must always be reamed with "petroleum" lubricant Withdraw the reamer regularly to remove chips. Then finish-ream the boreagain with a dry reamer. 8.
  • Page 104 Checking the valve seat wear limit 1. The valve seats in the 4-valve cylinder heads can be remachined. At the same time, the wear limit dimension must not be exceeded as this would mean that the hydraulic valve tappets may no longer function correctly.
  • Page 105 Engine, Cylinder Head, Valve Drive Checking and remachining valve seats Visuel inspection 1. Check that the valve seat sits securely in cylinder head. 2. Check the contact pattern. If the valve does make contact over the emire surface of the valve seat. remiII the seat slighdy.
  • Page 106 Check the contact pattern af the valve seat surface. 15 - 132 Engine, Cylinder Head, Valve Drive Valve dimensions 11864 Valve dimensions 944 S As from Model 87 Engine type M 44.40 Dimension 85/151 Intake Exhaust...

  • Page 107: Checking And Adjusting Installation Length Of Valve Springs

    2.0 + 0.2 mm thick. Tool (own construetion) Valve spring Sp No. 944.105.467.03 Auxiliary spring Sp No. 928.107.171.01 1. Machine a recess of approx. 10 mm width into valve-spring seat. Only install valve- spring seat for measurement.
  • Page 108 5. Using a depth gauge, measure from the top surface of the valve-spring seat, vertically downwards through the recess to the outer spring contact surface. Installation length Inlet valve 38.0 + 0.5 mm Exhaust valve 37.0 + 0.5 mm 6. The installation length can be adjusted using shims.
  • Page 109 CHANGING ENGINE OIL AND ENGINE OIL FILTER (16-VALVE ENGINES) Preconditioned: Engine at operating temperature. 1. Unscrew and remove oil filler cap. 2. Unscrew oil drain plug from oil pan and drain engine oil. 3. Remove oil filter with oil-filter wrench, Special Tool 9204.
  • Page 110 Removing and installing the pressure reducing valve Engine type M44.40 Se screw Pressure reducing valve O-ring O-ring 1. Remove the cylinder head cover and undo the set screw by 2 rums. 2. Ease the pressure reducing valve out of the seat with a screwdriverand take out upwards.

  • Page 111: Checking Cooling And Heating System For Leaks

    MIXING TABLE FOR COOLANT (Average values) Antifreeze Antifreeze Agent effective to - 25° C - 30° C - 35° C CHECKING HEATING AND COOLING SYSTEM FOR LEAKS (16-VALVE ENGINES) 1. Visual inspection for leaks. 2. Check routing of cooling and heating hoses, look for signs of porosity, swelling, cracks and rubbing.
  • Page 112 20 - 100 Blank Page...

  • Page 113: Table Of Contents

    REPLACING FUEL FILTER (16-VALVE ENGINES) 1. Disconnect fuel lines, always counter when slackening threaded connectors. Catch fuel exiting from lines in a suitable container. 2. Slacken retaining clamp and remove fuel filter. 3. Install new filter. Direction of flow is as indicated by the arrow.

  • Page 114: Checking Delivery Rate Of Fuel Pump

    Fuel Supply CHECKING DELIVERY RATE OF FUEL PUMP Precondition: Fuel filter and power supply OK. 1. Unbolt fuel return hose from pressure regulator. Connect a length of commercially available fuel hose and place one end in a graduated cylinder (capacity apprax. 1500 cc). 2.

  • Page 115: Table Of Contents

    FUEL SYSTEM LINE ROUTING (16-VALVE ENGINES) '87 MODELS ONWARD ENGINE TYPE M 44.40 1 Fuel pump A Air flow sensor 2 Fuel filter B Throttle valve housing 3 Fuel collector tube C Intake tube 4 Pressure damper D Idle actuator 5 Pressure regulator E Intake jet pump F Electric tank breather valve...
  • Page 116 24 - 100 Blank Page...
  • Page 117 REPLACING AIR FILTER ELEMENT (16-VALVE ENGINES) 1. Use a screwdriver to remove mounting screws and remove upper part of air filter. 3. Remove filter element and clean inside of lower half of air-filter housing with a lint-free cloth 4. Insert filter element, place housing cover in position and tighten mounting screws.

  • Page 118: Testing And Adjusting Specifications

    Testing and adjusting specifications Model 87 onward Engine type M 44.40/41 (3.0 I) Test Specifikation Electric fuel pump rate 850 cm Min. delivery Fuel pressure (engine stationary) DEE relay 3.8 +- 0.2 bar jumpered Checking value at idle approx. 3.3 +- 0.2 Leak test min.
  • Page 119 CHECKING FUEL PRESSURE TOOLS Description Pressure gage with hose from pressure tester Printed in Germany - XIII, 1987 L-Jetronic Fuel Injection Special Tool Remarks P 378 or VW 1318 Checking Fuel Pressure 24 - 103...
  • Page 120 L-Jetronic Fuel Injection CHECKING FUEL PRESSURE 1. Slacken and remove capped nut on test connection of fuel distribution line. Note: Be careful that sealing ball does not fall out when capped nut is removed. 2. Connect pressure gage with hose from pressure tester P 378 or VW 1318 to test connection.
  • Page 121 Checking idle speed and CO- with catalytic converter Model 87 onward Engine type M 44.40/41 (3.0 l) Note It is no longer possible to adjust idle speed CO on vehicles with catalytic converters. The Lambda probe remains connected while chekking idle speed and CO. Checking preconditions Engine in perfect mechanical condition.
  • Page 122 Checking idle speed and CO without catalytic converter Model 87 onward Engine type M 44.40/41 (3.0 l) Note It is no longer possible to adjust the idle speed. The throttle valve connector adjustment therefore no longer applies. Idle/CO adjustment Adjustment preconditions Engine in perfect mechanical conditions.
  • Page 123 Replacing air filter insert Model 89 onward Engine type M 44.41 (3.0 l) 1. Replace front end plate. Refer to 944 Workshop Manual Page 50 - 5. 2. Undo retaining clips and remove housing cover with filter insert. 3. Clean inside of filter housing with lint-free cloth.
  • Page 124 26 - 100 Blank Page...
  • Page 125 CHECKING TIGHTNESS OF EXHAUST SYSTEM FLANGES (16-VALVE ENGINES) 1. Check tightness of exhaust flanges and check entire exhaust system for leaks. 2. Check tightness of hex nuts on exhaust manifold/cylinder head flange. 3. Check tightness of all flange connectians in exhaust system, together with oxygen sensor and exhaust extractian tube.
  • Page 126 28 - 100 Blank Page...

  • Page 127: Equipment Table

    Spark plugs Type/Model 944 S Ignition trigger box Type/Model 944 S Printed in Germany - XIII, 1987 Version 944 602 115 00 Bosch No. 0 221 118 322 Version 928 602 211 01 Bosch No. 1 235 522 395 Version...
  • Page 128 DME control unit Type/Model 944 S Mod. '87 944 S Mod. '88 Hall probe for knock sensors Type/Model 944 S Knock sensor Type/Model 944 S 28 - 102 Ignition System Version 944.618.124.00 944.618.124.01 944.618.124.01 Version 944.606.170.01 Version 944.606.145.00 Remarks M 44.40 Spare part M 44.40...
  • Page 129 DME CONTROL UNIT CODING, 944 S, '87 MODELS ONWARD 1 - 944.612.525.01 2 - 928.607.421.00 3 - 928.607.422.00 4 - 944.612.522.00 Country Characteristic-map switch, ter. 54 USA, rest of world with catalytic converters California, Japan EC, without catalytic converters Sweden Australia 944.612.525.01...

  • Page 130: Replacing Spark Plugs

    Ignition System REPLACING SPARK PLUGS, 944 S 1. Pull off spark plug caps. 2. Unscrew spark plugs with commercially available wrench. A spark-plug wrench is supplied as part of the car's toolkit. Tightening torque: 25 - 30 Nm (18 - 22 ftlb).
  • Page 131 Equipment tabte 89 models onward Engine type M 44.41 (3.0 l) Ignition Coll Type/Model Version 944 S 2 944 602 115 00 Bosch No. 0 221 118 322 Distributor (Cap) Type/Model Version 944 S 2 928 602 211 01 Bosch No.
  • Page 132 DME Control unit Type/Model 944 S 2 Mod. ´89/90 944 S 2 Mod. ´91 Hall probe for knock sensors Type/Model 944 S 2 Knock sensor Type/Model Version 944 S 2 944.606.145.00 28 - 106 Ignition System Version 944.618.124.02 944.618.124.05 Version 944.606.170.01...
  • Page 133 Coding - DEE control unit 944 S 2, Model 89 onwards 1 - 928.607.421.00 2 - 928.607.422.00 Country USA, rest of world with catalytic convertor California, Japan Rest of world without catalytic converter Coding - DEE control unit 944 S 2, Model 89 onwards...
  • Page 134 DME-Diagnosis / Troubleshooting Dr. Ing. h.c. F. Porsche Aktiengesellschaft...
  • Page 135 944 S/944 S2 Test Point DME - Diagnosing/Troubleshooting Printed In Germany - XXI, 1989 Fuel System - Electronic Control Description Precautions Important Vehicle Information Testing Requirements Effects of Faults (Cross Reference List) DME Control Unit Plug Connections Power Supply Idle Speed Contact...
  • Page 136 D 24/28 - 2 Fuel System - Electronic Control 944 S/944 S2 DME - Diagnosing/Troubleshooting Printed In Germany - XXI, 1989...
  • Page 137 944 S/944 S2 Important Vehicle Information Always turn off the ignition or disconnect the battery for resistance tests (if not, the tester could be destroyed). Always disconnect the speed sender plug for compression tests (if not, there could be dangerous high tension and damaged insulation on the ignition coil, high tension distributor and ignition leads).
  • Page 138 D 24/28 - 4 Fuel System - Electronic Control - All sender and ignition timing signals of Porsche models can be checked with the engine reglers recommended by Porsche. Instructions for connection of testers on a car will be different depending on the...
  • Page 139 Diagnosable DME Control Unit Self-diagnosis with a fault memory, with which it is possible to detect and store certain injection. ignition and knock regulating system faults, is integrated in the DME control unit of 944 S cars beginning with 1988 models.
  • Page 140 24/28 This DME 944 S Diagnosing/Troubleshooting Plan is based on the contents of the fault memory. Paths not included in self-diagnosis can be diagnosed with conventional equipment (Test Points 17-25. see Fault List). Troubleshooting requires that the person performing the tests is familiar with the location of components, the function and technical interconnections of the systems being tested (model information).
  • Page 141 24/28 944 S/944 S2 Fuel System - Electronic Control This page are missing or blank in the book ! DME - Diagnosing/Troubleshooting D 24/28 - 7 Printed In Germany - XXI, 1989...
  • Page 142 24/28 Fuel System - Electronic Control 944 S/944 S2 This page are missing or blank in the book ! D 24/28 - 8 DME - Diagnosing/Troubleshooting Printed In Germany - XXI, 1989...
  • Page 143 944 S/944 S2 Fault, Fault Code Test Point a) Perm. pos. (B + ) Power supply for Testing: control unit Connect a voltmeter on terminal 24 (-) and terminal 18 ( +) of the control unit plug with help of test leads.
  • Page 144 Idle speed contact made Idle speed contact broken 1332 (idle speed contact made) 0000 (idle speed contact broken) < 10 > 1° = < 10 > 1° = 944 S/944 S2 DME - Diagnosing/Troubleshooting Printed In Germany - XXI, 1989...
  • Page 145 944 S/944 S2 Fault, Fault Code Test Point 3 Full load contact ( ) Ground short Fault Code 1_13 DME - Diagnosing/Troubleshooting Printed In Germany - XXI, 1989 Fuel System - Electronic Control Possible Causes, Elimination, Remarks Check via circuit input test with a 9288 System Tester or 9268 Tester.
  • Page 146 Break ( DME control unit of the 944 S selects a resistance value, which is stored in the control unit's memory and is approximately equal to that of an engine at operating temperature. There is no enrichment from a faulty NTC II when the engine is warm (emergency running program).
  • Page 147 944 S/944 S2 Fault, Fault Code Test The ratio between Up (potentiometer voltage) and Uv (power supply voltage) can be read in the "actual value" menu with a 9288 System Tester. Point 5a: Air flow When opening the air flow sensor plate the ratio must be about 0.0 to 1. If not:...
  • Page 148 The pulse duty factor must change and the idle speed must remain constant. If not: D 24/28 - 14 Fuel System - Electronic Control Possible Causes, Elimination, Remarks 944 S/944 S2 DME - Diagnosing/Troubleshooting Printed In Germany - XXI, 1989...
  • Page 149 944 S/944 S2 Fault, Fault Code Connect two-pin DME test lead (Bosch No. 1 684 463 093) between the speed control and plug. Connect and adjust engine tester to supplied operating instructions. Make sure that electric lead connections do not have contact with vehicle ground (danger of short).
  • Page 150 Display at: D 24/28 - 16 Fuel System - Electronic Control Possible Causes, Elimination, Remarks 0° C = 4.4-6.8 k 15-30°C = 1.4-3.6 k 40° C = 1-1.3 k 944 S/944 S2 DME - Diagnosing/Troubleshooting Printed In Germany - XXI, 1989...
  • Page 151 944 S/944 S2 Fault, Fault Code If no display: Disconnect plug on air flow sensor. Connect an ohmmeter on air flow sensor terminals 1 and 4 with help of test leads. Display: same as above. Note: In case of a break, there will be a replacement value equal to an intake air temperature of 20°...
  • Page 152 Turn off ignition. Disconnect Hall plug. Start the engine. Idle speed ignition timing will adjust itself to approximately 4° before TDC (944 S). There must be a certain load signal from the air flow sensor in case of 944 S2 cars.
  • Page 153 944 S/944 S2 Fault, Fault Code Test Start the engine - fuel pump must run during engine starting. Point 15: It not: relay (fuel Turn off ignition. Disconnect control unit plug. Connect terminal 3 and terminal 24 pump) (V) on the control unit plug with help of a test lead.
  • Page 154 (California as Always replace a faulty display lamp with a specified lamp. 1991 models) D 24/28 - 20 Fuel System - Electronic Control Possible Causes, Elimination, Remarks 944 S/944 S2 DME - Diagnosing/Troubleshooting Printed In Germany - XXI, 1989...
  • Page 155 944 S/944 S2 Test Point 18: Fuel Pressure Fuel collection pipe has a test connection at left front. Unscrew cap nut of the test connection. Important! Inserted ball seal could fall out! Connect P 378 pressure tester on the test connection. Start the engine.
  • Page 156 0.5 bar pressure in the intake system. Leaks will cause the pressure in the system to drop quickly. (944 S: shut the safety pressure valve for crankcase breathing.) Remarks: Flashing Fault Code 1_23 (oxygen regulation on stop) is displayed in cars with...
  • Page 157 Power is supplied to the DME control unit of a 944 S via terminal 30 (battery +) in addition to via ignition lock terminal 15. 24/28 D 24/28 - 23...
  • Page 158 Sender distance: Between gear ring and sender: 0.8 +- 0.3 mm. D 24/28 - 24 Fuel System - Electronic Control 944 S/944 S2 1 - Speed signal 2 - Reference mark signal DME - Diagnosing/Troubleshooting Printed In Germany - XXI, 1989...
  • Page 159 944 S/944 S2 No display: Disconnect plug of speed sender on plug plate in the engine compartment. Connect tester leads on middle and outside pins of the plug on the sender end of the plug with help of test leads (terminals 1 and 2, pin end).
  • Page 160 Ignition timing and engine speed can be read direct in the "actual value" menu with a 9288 System Tester. Test value: (944 S + 944 S2) At 840 +- 40 rpm 10° +- 3° If there is no signal, check: - Power supply to ignition final stage and ignition coil.
  • Page 161 944 S/944 S2 f) Ignition final stage control signal test Connect DME control unit plug. Connect oscilloscope's positive tester lead on terminal 5 and negative tester lead on terminal 2 of the disconnected final stage plug. Operate starter motor. Oscilloscope should display the control signal of the DME control unit.
  • Page 162 Starter speed Remarks: If the engine cannot be started or the idle speed drops, change tester connections on the Bosch lead and check tester adjustment. 944 S/944 S2 DME - Diagnosing/Troubleshooting Printed In Germany - XXI, 1989...
  • Page 163 Information for idle speed and idle speed CO test: a) Idle speed 944 S engines have adaptive idle speed volumetric efficiency regulation since 1987 modeIs. This means that the idle speed of all versions does not have to be adjusted. The...
  • Page 164 In addition, the system must be adapted. D 24/28 - 30 Fuel System - Electronic Control 944 S/944 S2 DME - Diagnosing/Troubleshooting Printed In Germany - XXII, 1990...
  • Page 165 944 S/944 S2 Coding of Control Unit - 944 S Pertinent curve families are integrated in the DME control unit, in order to be able to comply with the legislation of different countries. They can be read direct in the "actual value" menu with a 9288 System Tester.
  • Page 166 24/28 Coding af Control Unit - 944 S 2 Country All with cat. conv. Califomia, Japan All without cat. conv. As from model year '91, the code for California and Japan is being deleted (identical worldwide). D 24/28 - 32...
  • Page 167 944 S/944 S2 Check-Engine Lamp (Malfunction Indicator Light M.I.L) As from model year '91, Califomian legislation prescribes a waming lamp which lights up if a part relevant to the exhaust gas fails. As a function check of the warning lamp, it lights up when the ignition is switched on and goes out once the engine is running when this is started without depressing the accelerator.

This manual is also suitable for:

944 s944 s2944 1987

Table of Contents

Save PDF