Volkswagen New Beetle. Manual - part 1756

Fig. 20: Locating Fuel Pump Assembly 
Courtesy of VOLKSWAGEN UNITED STATES, INC. 

IGNITION SYSTEMS 

Any fault with ignition system will set DTC. See appropriate SELF-DIAGNOSTICS article in ENGINE 
PERFORMANCE.  

IDLE SPEED & IGNITION TIMING 

Any fault with idle speed or ignition timing will set a DTC. See appropriate SELF-DIAGNOSTICS article in 
ENGINE PERFORMANCE.  

 

2003 Volkswagen New Beetle GLS 

1998-2003 ENGINE PEFORMANCE Basic Diagnostic Procedures - Beetle - Gasoline

  

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2000-2003 ENGINE PERFORMANCE 

Basic Diagnostic Procedures - Beetle, Diesel 

INTRODUCTION 

The following diagnostic steps will help prevent overlooking a simple problem. This is also where to begin 
diagnosis for a no-start condition.  

The first step in diagnosing any driveability problem is verifying the customer's complaint with a test drive 
under the conditions the problem reportedly occurred.  

Information that involves ECM sensors and components that generate DTCs are not covered in this article. See 
appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.  

Performing a thorough Visual Inspection and checking for DTCs, may pin point faulty circuit (vacuum or 
electrical) and/or faulty component or adjustment. See VISUAL INSPECTION . After performing Visual 
Inspection, check for DTCs, see appropriate SELF-DIAGNOSTICS article. Most engine control problems result 
from mechanical breakdowns, poor electrical connections, or damaged/misrouted vacuum hoses.  

PRELIMINARY INSPECTION & ADJUSTMENTS 

VISUAL INSPECTION 

1. Visually inspect all electrical wiring, looking for chafed, stretched, cut or pinched wiring. Ensure 

electrical connectors fit tightly and are not corroded. Check for loose or defective electrical connections 
on starter motor. Ensure all vacuum hoses are properly routed and are not pinched or cut. See Fig. 1 to 
verify routing and connections. Inspect air induction system for possible vacuum leaks.  

2. Check air filter for restriction or damage. Ensure turbocharger and charge air cooler inlet and outlet ducts 

clamps are tight. Ensure glow plug electrical connectors are tight. 

NOTE:

Perform all voltage tests using Digital Volt-Ohmmeter (DVOM) with a minimum 
10-megohm input impedance, unless stated otherwise in test procedure. 

 

2003 Volkswagen New Beetle GLS 

2000-2003 ENGINE PERFORMANCE Basic Diagnostic Procedures - Beetle, Diesel

  

 

2003 Volkswagen New Beetle GLS 

2000-2003 ENGINE PERFORMANCE Basic Diagnostic Procedures - Beetle, Diesel

  

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Fig. 1: Vacuum Hose Routing Diagram 
Courtesy of VOLKSWAGEN UNITED STATES, INC. 

MECHANICAL INSPECTION 

Engine Compression 

Engine must be at operating temperature. Battery must be fully charged.  

1. Disconnect 10-pin fuel cut-off valve electrical connector (located on diesel injection pump) before 

performing compression check.  

2. Disconnect connectors from glow plugs. Remove all glow plugs.  

3.  

Thread in VAG 1381/12 adaptor in place of glow plugs. Check compression using VAG 1763 
compression tester. See Fig. 2 . Operate starter until tester displays no further increase in pressure. Record 

NOTE:

Follow manufacturers operating instructions for correct use of 
compression tester. 

 

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2000-2003 ENGINE PERFORMANCE Basic Diagnostic Procedures - Beetle, Diesel

  

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compression readings for each cylinder. 

Fig. 2: Testing Compression Using VAG 1763 
Courtesy of VOLKSWAGEN UNITED STATES, INC. 

4. Check compression readings against specifications. See COMPRESSION SPECIFICATIONS table. If 

any cylinder reading is not as specified, repair as necessary.  

COMPRESSION SPECIFICATIONS 

NOTE:

Glow plug tightening torque is 11 ft. lbs. (15 N.m). 

Application 

(1)

Specification 

Normal Compression Pressure 

New Engine 

363-450 psi (25.0-31.0 bar) 

Minimum Compression Pressure 

276 psi (19.0 bar) 

 

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2000-2003 ENGINE PERFORMANCE Basic Diagnostic Procedures - Beetle, Diesel

  

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