red light at dash/hard starting

Asked by Oct 19, 2009 at 01:19 PM about the Mercedes-Benz 300-Class

Question type: Maintenance & Repair

This vehicle is a 1988 300e. Changed out oxygen sensor, red light remains on.
Engine cranks fine, engine fires within 6sec or so, but will not operate properly if gas pedal is worked. Takes about a minute for engine to run smoothly. After engine is warm there is no problem starting and operating engine.

2 Answers

75

These are the most common issues. Cold Start Valve E.H.A. Valve Fuel Accumulator Fuel Pump Voltage Regulator Alternator Ignition Coil Low compression Massive vacuum leak at the intake manifold Other possible combinations of these units may cause your issue, though it is not as common. Air Temp. Sensor Altitude Sensor Fuel Injector Fuel Injector Seal Fuel Pressure Regulator Water Temp. Sensor Fuel Pump Check Valve Fuel Screen Fuel Tank Vent Valve Fuel Pump Relay Ignition Wire KE Control Unit Reference Sensor Wiring Harness

1 people found this helpful.

Thanks for the input. I am thinking the cold start circut. I have an open circut through the feed wire. No voltage when trying to start engine. The sensor unit at the cold start valve shows no external grounding. I beleive the engine would not perform as good as it does if there were an excessive vacume leak. Is the red dash light connected to the cold start circut? I am trying to locate through the library a manual showing troubling shooting. No luck so far. Thanks again for you assistance.

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