Cranks but does not start

Hi,

If you checked fuel pressure and it is good, then I suspect it is an ignition spark issue. Do me a favor. Follow this link and see if there is spark to the plugs. If there is no spark, there is a sensor in the distributor that functions the same as a crankshaft position sensor. It may have failed. See the pic below.

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Also, here is a quick check from the manual for testing:

1995 Volkswagen Jetta III (1H2) L4-2.0L (ABA)
System Quick Check (Engine Will Not Start)
Vehicle Powertrain Management Ignition System Testing and Inspection Component Tests and General Diagnostics System Quick Check (Engine Will Not Start)
SYSTEM QUICK CHECK (ENGINE WILL NOT START)
Pretest Condition
Engine will not start

- If the engine does not start, the fundamental step in trouble shooting the ignition system is to determine whether or not the system is creating any kind of spark at the spark plug. If a spark is present, it is the ignition systems efficiency/accuracy or another system's function that is in question. If no spark is present, more detailed testing of wiring, connections, battery or individual components is needed.

NOTE: Battery must be fully charged and terminals must be in good condition for all tests.

1. To check for spark, turn ignition OFF.
2. Remove a spark plug wire.
3. Connect it to a good (preferably new) spark plug and hold the outer electrode, with insulated pliers, to ground.

WARNING: Use insulated pliers to test spark plug, other equipment may cause bodily harm or death.

4. Have an assistant crank the engine. Look for spark in the plug gap.

a. If a bright blue spark is available, ignition system is healthy, fault may lie in the fuel, computerized engine control or other related system. End of test.
b. A yellow/orange spark is weaker and indicates that ignition system is not operating at peak efficiency. Check such components as the coil/plug wires, cap and rotor. If no fault can be found, check the rest of the ignition system components in this section. If no fault found, refer to COMPUTERIZED ENGINE CONTROLS to test the remaining ignition components.
c. If there is no spark, check the wiring to ignition coil [1], also check the ignition switch [2], ignition coil, Hall effect sender [3] and power output stage [3]. If no fault can be found, check the rest of the ignition system components in this section. If no fault found, refer to COMPUTERIZED ENGINE CONTROLS to test the remaining ignition components.

5. For additional trouble shooting information

6. Reconnect spark plug wire.

[1]When the ignition is in the ON position, there should be approx. 12 volts
[2]Refer to BODY ELECTRICAL, SAFETY AND ENTERTAINMENT.
[3]Refer to COMPUTERIZED ENGINE CONTROLS.

Let me know what you find.

Joe

Hi,

Okay. Now we need to continue testing. There is an ignition coil hall effect sensor that needs checked next. Here are the directions. The attached pic correlates with the directions.

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1995 Volkswagen Jetta III (1H2) L4-2.0L (ABA)
Component Tests and General Diagnostics
Vehicle Powertrain Management Sensors and Switches - Powertrain Management Sensors and Switches - Ignition System Hall Effect Sensor Testing and Inspection Component Tests and General Diagnostics
COMPONENT TESTS AND GENERAL DIAGNOSTICS
NOTE: The Hall effect sender should only be tested if the engine does not start and there is no spark at the spark plugs. To further assist you during testing, use the wiring diagrams.

CAUTION: Always turn ignition OFF when connecting or disconnecting Hall sender or ignition power stage unit terminals. Be sure to check the integrity of the wires, connectors, battery terminals and fuses before replacing an expensive component.

- Be sure ignition coil is in good working order. If needed, test coil first,
- Be sure ignition power stage unit is in good working order. If needed, test power stage unit after coil test.
- Remove distributor cap and visually inspect the Hall sender. If shutter wheel is touching the sender, there is corrosion or other damage, replace and retest with new component.
- Disconnect the coil wire from the center of distributor cap and connect it to ground so engine can't start.

Digifant I Coil Power Stage Connector

Pic 1

- Peel back the protective boot connector on the Hall sender harness connector.
- Connect an LED test light between the center connector terminal and either of the outer terminals.
- Turn the engine over using the starter. The LED should flicker.
- If not, replace and retest with new Hall effect sender.
- Disconnect all test equipment, reconnect the coil wire and cover the Hall sender connector with its boot.

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Here are the directions for testing the coil. Pic 2 correlates with these directions.

1995 Volkswagen Jetta III (1H2) L4-2.0L (ABA)
Component Tests and General Diagnostics
Vehicle Powertrain Management Ignition System Ignition Coil Testing and Inspection Component Tests and General Diagnostics
COMPONENT TESTS AND GENERAL DIAGNOSTICS
CHECKING IGNITION COIL

- Disconnect harness connector and ignition wire from Ignition Coil (N152).

Pic 2

- Check primary resistance between terminals -1- and -15- using Fluke 83 multimeter.

Specified value: 0.5 - 0.7 Ohms.

- Check secondary resistance between terminals -4- and -15-.

Specified value: 3000 to 4000 Ohms.

- If NOT OK:

- Remove Ignition Coil and disconnect Ignition Coil Power Output Stage (N157).
- Repeat test.
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Here are the directions for testing the power output stage.

1995 Volkswagen Jetta III (1H2) L4-2.0L (ABA)
Component Tests and General Diagnostics
Vehicle Powertrain Management Relays and Modules - Powertrain Management Relays and Modules - Ignition System Ignition Control Module Testing and Inspection Component Tests and General Diagnostics
COMPONENT TESTS AND GENERAL DIAGNOSTICS
PROCEDURE

Ignition Coil With Power Stage

Pic 3

- Disconnect the high tension coil wire from the ignition coil output terminal (terminal 4).
- With the ignition "OFF" remove the power stage harness connector.

Digifant I Coil Power Stage

pic 4

- Connect a suitable volt/ohm meter between terminals 1 and 3 of the power stage harness connector.
- Turn ignition switch "ON".

The correct reading should be battery voltage (approx. 12 VDC).

CAUTION:
- Always turn the ignition switch "OFF" before changing meter ranges, and before disconnecting or connecting the meter probes. Doing so with the ignition switch turned "ON" risks permanent control unit damage.

- If not, wiring harness may be defective check and repair as necessary.

Digifant I Injector Harness Connector
pic 5

- Turn ignition switch "OFF". Disconnect the multimeter. Disconnect the fuel injector main harness connector near the fuel rail.

Digifant I Coil Testing
pic 6

- Connect an LED test light between terminals 1 and 2 of the power stage harness connector.
- With the ignition switch crank the engine briefly, then turn ignition switch "OFF".

The LED light must flicker.

- If the LED test light does not flicker, the Camshaft Position (CMP) Sensor, the Motronic control unit, or the wiring may be defective.
- If the test light does flicker continue.
- With the ignition "OFF", reconnect the fuel injector main harness connector, coil wire, and the power stage harness connector.

Digifant I Coil Power Stage Connector
pic 7

- Connect a suitable volt/ohm meter between terminals 1 and 15 of the ignition coil.
- Turn the ignition switch "ON".

The voltage at the ignition coil should briefly rise to a least 2 volts, then drop to zero volts after 1 to 2 seconds.

- If the correct results are not obtained replace the ignition power stage.

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I realize this is a lot. Let me know what you find.

Take care,
Joe