Troubleshooting sequence
Does the starter work?
If the starter does not turn on or turns poorly, read the section below «Cause of failure - electrical system». If, on the contrary, he confidently cranked the engine, you need to answer the following questions in turn in order to further narrow the search circle.
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Do spark plugs spark?
Disconnect the wire tip from one of the spark plugs, unscrew the spark plug, insert into the tip. Now connect the spark plug with the auxiliary cable for «cigarette lighter» with cylinder block (Auxiliary cable not shown in illustration for better clarity). Have an assistant turn the starter. Do not touch the high voltage wire and spark plug - dangerous! Are sparks visible? If yes, move on to the next question. If not, read on to the section «Cause of failure - ignition system».
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Is fuel getting into the injection system?
Disconnect the fuel supply line from the fuel filter at the rear right in the engine compartment. Caution: Models with 4- and 5-cylinder KE-Jetrinic / Motronic engines may release a relatively large amount of high-pressure fuel. Therefore, when loosening the connection, put a thick rag on the fitting. You can extend the fuel supply line with a hose and lower its end into a container. Have an assistant crank the starter briefly.
If gasoline is supplied, the fuel pump should be running. If gasoline is supplied, then only the injection system remains as a source of malfunctions. Or the fuel pump, although it works, but does not provide the desired pressure.
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Visual check first
- Has the wire end come loose from any part of the ignition or injection system?
- Check high voltage wires to ignition coil, ignition distributor and spark plug tips (the ignition must not be switched on!) on tightness.
- Are all vacuum hoses in the engine compartment connected to the correct fittings?
- Is there any condensation on or under the distributor cap? All elements of the ignition system - including the ignition coil - must be clean and dry, otherwise there is a great danger of current leakage and overvoltage breakdowns.
- Smell of gasoline in the engine bay? Check fuel line for tightness and tight fit.
Cause of failure - electrical system
- Indicators on the dashboard do not light up or do not blink when the ignition is on: the battery is completely discharged or the battery terminals are disconnected.
- The indicators go out when the starter is turned on: the battery is significantly discharged or it has already exhausted its resource, or there is an inter-turn circuit in the starter.
- The indicator light becomes dimmer when the key is turned; the starter does not turn: the solenoid relay is stuck or it is faulty; the starter may be defective.
- When the key is turned, the indicators light up or flash normally; the starter does not turn: defective contact of terminal 50 in the ignition switch, poor contact in the wiring to terminal 50 on the solenoid relay, or the solenoid relay is faulty.
Cause of failure - ignition system
- Are all wire lugs of the ignition coil and ignition distributor correctly installed?
- Are there any cracks in the ignition coil housing, traces of burning from a jumping spark?
- Remove distributor cap. Can traces of current leakage be found on its inside? Does the contact carbon spring well in the middle of the lid? Are traces of copper corrosion visible?
- If all of the above is correct, only a complete check of the entire ignition system will help.
Cause of failure - fuel supply system
- Check if there is gasoline in the fuel tank. An empty gas tank is not at all such a ridiculous idea as it might seem at first glance. The lack of fuel is detected primarily by interruptions in the operation of the engine when cornering.
- Faulty fuel pump.
- Clogged fuel filter.
- With a good fuel supply, especially in the case of constant problems with starting, the injection system should be checked.
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