WIXLIB

1.9-Liter TDI Enginewith Pump Injection(Pumpe Düse)Design and FunctionSelf-Study ProgramCourse Number 841303

Volkswagen of America, Inc.Service TrainingPrinted in U.S.A.Printed 10/2003Course Number 841303 2003 Volkswagen of America, Inc.All rights reserved. All information containedin this manual is based on the latestinformation available at the time of printingand is subject to the copyright and otherintellectual property rights of Volkswagen ofAmerica, Inc., its affiliated companies and itslicensors. All rights are reserved to makechanges at any time without notice. No partof this document may be reproduced,stored in a retrieval system, or transmittedin any form or by any means, electronic,mechanical, photocopying, recording orotherwise, nor may these materials bemodified or reposted to other sites withoutthe prior expressed written permission ofthe publisher.All requests for permission to copy andredistribute information should be referredto Volkswagen of America, Inc.Always check Technical Bulletins and theVolkswagen Worldwide Repair InformationSystem for information that may supersedeany information included in this booklet.Trademarks: All brand names and productnames used in this manual are trade names,service marks, trademarks, or registeredtrademarks; and are the property of theirrespective owners.

Table of ContentsIntroduction . 11.9-Liter TDI Engine with Pump Injection SystemEngine – Mechanics . 2Development of the 1.9-Liter TDI Engine with PumpInjection System, Technical Data – 1.9-Liter TDI Enginewith Pump Injection System, Trapezoidal Piston andConnecting Rod, Toothed Belt DriveFuel Supply . 8Fuel Supply System Overview, Fuel Pump,Distributor Pipe, Fuel Cooling SystemPump Injection System . 15Pump/Injectors, Design, Injection CycleEngine Management . 281.9-Liter TDI Engine EDC 16 System Overview,Sensors, ActuatorsGlow Plug System . 53Glow Plug SystemFunctional Diagram . 54EDC 16 Functional Diagram for 1.9-Liter TDI EngineService. 56Self-Diagnosis, Pump/Injector Adjustment, Special ToolsNew!Knowledge Assessment . 61Important/Note!The Self-Study Program provides you with informationregarding designs and functions.The Self-Study Program is not a Repair Manual.For maintenance and repair work, always refer to thecurrent technical literature.i

Introduction1.9-Liter TDI Engine withPump Injection SystemThe demands on the modern diesel enginefor increased performance and fueleconomy, and reduced exhaust emissionsand noise levels are growing constantly.Good fuel and air mixture preparation is akey factor in meeting these requirements.This calls for efficient injection systems thatproduce high injection pressures to ensurethat the fuel is well atomized. It is alsonecessary to precisely control the start offuel injection and the injection quantity.The pump injection system meetsthese requirements.In 1905, Rudolf Diesel came up with theidea of a pump/injector, combining theinjection pump and injector in one unitin order to dispense with high-pressurelines and achieve high injection pressures.At the time, however, he did not havethe technical means to put his ideainto practice.SSP304/032Diesel engines with mechanically controlledpump injection systems have been in usein ships and trucks since the 1950s.In association with Bosch, Volkswagen hassucceeded in developing a diesel enginewith a solenoid valve controlled pumpinjection system suitable for use inpassenger cars.The 1.9-liter TDI engine with the new pumpinjection system meets the stringentdemands for improved performance andcleaner emissions.With continuing advances like this one,Rudolf Diesel’s vision of “smoke- andodor-free exhaust gases” may one daybecome a reality.SSP209/0271

Engine – MechanicsDevelopment of the1.9-Liter TDI Engine withPump Injection SystemThe new 100 bhp (74 kW) 1.9-liter TDIengine with pump injection system wasdeveloped from the existing 109 bhp (81kW) 1.9-liter TDI engine with a distributorinjection pump and no intermediate shaft.The pump injection system comprises theonly significant difference between thetwo engines.This Self-Study Program concernsthe design and function of the new pumpinjection system, and the modificationsto the fuel system, engine managementsystem, and engine mechanicalcomponents to accommodate the system.A diesel engine with the pump injectionsystem has the following advantages overan engine with a distributor injection pump: Low combustion noise. Low fuel consumption. Clean emissions.SSP209/005 High efficiency.These advantages are attributable to: The high injection pressures of up to27,846 psi (192,000 kPa / 1,920 bar). Precise control of the injection cycle. The pre-injection phase.2

Engine – Mechanics Engine codeBEWlbs-ft NmhpkW221 30012190184 25010175148 2008060111 150604574 1004030372015 Displacement115.7 cu in (1,896 cm3) Bore3.13 in (79.5 mm) Stroke3.76 in (95.5 mm) Compression ratio19.0 : 1 Maximum power output100 bhp (74 kW) @ 4000 rpmTorque TypeFour-cylinder in-line engine with twovalves per cylinder500OutputTechnical Data –1.9-Liter TDI Engine withPump Injection System0100020003000Speed (rpm)40005000SSP209/006 Maximum torque177 lbs-ft (240 Nm) @ 1800 to 2400 rpm Engine managementEDC 16 Firing sequence1-3-4-2 Emission ControlBin 10 EPA Federal Emissions Concept,OBD II, catalytic converter, water-cooledEGR system3

Engine – MechanicsTrapezoidal Pistonand Connecting RodTo accommodate the higher combustionpressures in the 1.9-liter TDI engine withpump injection system than areencountered in the base engine, the pistonhub and the connecting rod eye aretrapezoidal in shape.SSP209/0074

Engine – MechanicsIn comparison with the conventionalparallelogram-shaped link between thepiston and connecting rod, the trapezoidalconnecting rod eye and piston hub have alarger contact surface area at the piston pinowing to their shape.Force Distribution in a Parallelogram-ShapedPiston and Connecting RodCombustion ForceContact SurfaceSSP209/008This distributes the combustion forces overa larger area and relieves the load on thepiston pin and connecting rod.Force Distribution in a Trapezoidal Pistonand Connecting RodContact SurfaceCombustion ForceSSP209/0095

Engine – MechanicsToothed Belt DriveHigh pump forces are required to generatehigh injection pressures of up to 27,846 psi(192,000 kPa / 1,920 bar).These forces subject the components ofthe toothed belt drive to high loads.To relieve the load on the toothed belt,several modifications have been made. A vibration absorber integrated in thecamshaft gear reduces vibration inthe toothed belt drive. The toothed belt is about 0.20 inch(5 mm) wider than the toothed belt usedin the base engine. Higher forces can betransmitted by the larger surface area. A hydraulic tensioner keeps thetoothed belt evenly tensioned indifferent load states. Some of the teeth on the crankshafttiming belt gear have a larger gapclearance to reduce toothed belt wear.SSP209/089GapClearanceTo relieve the load on the toothed beltduring the injection cycle, the crankshafttiming belt gear has two pairs of teeth witha larger gap clearance than the other teeth.SSP209/886

Engine – MechanicsFunctionDuring the injection cycle, the highpumping forces exert a heavy load on thetoothed belt.The camshaft timing belt gear is sloweddown by the pumping forces. At the sametime, the combustion process speeds upthe crankshaft timing belt gear. The toothedbelt is stretched and the pitch is temporarilyincreased as a result.Because of the engine firing order, thisstretching process occurs at regularintervals and the same teeth on the timingbelt gear are in mesh with the toothed beltevery time.Deceleration ForcePitchNon-uniform tooth gap clearanceOn the 1.9-liter TDI engine with pumpinjection system, the crankshaft timing beltgear teeth have a larger gap clearance atthese points to compensate for the changein belt tooth pitch and thus reduce toothedbelt wear.Acceleration ForceSSP209/0917

Fuel SupplyFuel Supply System OverviewA mechanical fuel pump sucks the fuel outof the fuel tank through the fuel filter andpumps it along the supply line in thecylinder head to the pump/injectors.The fuel that is not required for injection isreturned to the fuel tank via the return linein the cylinder head, a fuel temperaturesensor, and a fuel cooler.Fuel Temperature Sensor G81 –Determines the temperature of thefuel in the fuel return line and sends acorresponding signal to the Diesel DirectFuel Injection Engine Control Module J248.Fuel Cooler – Cools the returning fuelto prevent excessively hot fuel frombeing routed back to the fuel tank.Fuel TankFuel Filter – Protects the injectionsystem against contamination andwear caused by particles and water.Non-Return Valve – Prevents fuelfrom the fuel pump flowing back intothe fuel tank while the engine is notrunning. It has an opening pressureof 2.9 psi (20 kPa / 0.2 bar).8

Fuel SupplyPressure Limiting Valve Bypass –If there is air in the fuel system,for example when the fuel tankis empty, the pressure limitingvalve remains closed. The air isexpelled from the system by thefuel flowing into the tank.Cylinder HeadFuel Return Line PressureLimiting Valve – Keeps thepressure in the fuel return lineat 14.5 psi (100 kPa / 1 bar).This maintains a forceequilibrium at the pump/injector solenoid valve needle.Restrictor – Located between thefuel supply line and the fuel returnline. Vapor bubbles in the fuel supplyline are separated through therestrictor into the fuel return line.Strainer – Collects vapor bubbles in thefuel supply line. These vapor bubbles arethen separated through the restrictorinto the return line.Fuel Pump Rotor – Pumps the fuel fromthe fuel tank through the fuel filter andthe fuel supply line in the cylinder headto the pump/injectors.Fuel Supply Line Pressure Limiting Valve –Regulates the fuel pressure in the fuel supply line.The valve opens when the fuel pressure exceeds109 psi (750 kPa / 7.5 bar). Fuel is routed back tothe suction side of the fuel pump.SSP209/0189

Fuel SupplyFuel PumpThe fuel pump is located directly behindthe vacuum pump at the cylinder head.It moves the fuel from the fuel tank to thepump/injectors.Both pumps are driven jointly by thecamshaft. They are collectively known asa tandem pump.There is a fitting on the fuelpump for connecting pressuregauge VAS 5187 to check thefuel pressure in the supply line.Please refer to the Repair Manualfor instructions.Vacuum PumpFuel PumpFuel Return LineFuel Supply LinePressure GaugeConnection FittingSSP209/04910

Fuel SupplyThe fuel pump is a blocking vane-cell pump.The blocking vanes are pressed against thepump rotor by spring pressure. This designenables the fuel pump to deliver fuel evenat low engine speeds.The fuel ducting system within the pumpis designed so that the rotor alwaysremains wetted with fuel, even if the tankhas been run dry. This makes automaticpriming possible.Fuel Supply LinePressure Limiting ValveBlocking VanesConnection forFuel Supply LineRestrictorFrom FuelReturn Line inCylinder HeadFuel ReturnLine PressureLimiting ValveConnection forFuel Return LineRotorStrainerTo Fuel Supply Linein Cylinder HeadSSP209/05011