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ischmitz ischmitz is offline
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Join Date: May 2002
Location: Santa Barbara, CA
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Fuel pump needs to come on (with good DME relay) when only one of the following conditions is true: So either (1) or (2)

1. START terminal energized (engine cranking)
2. Motion detected at the flywheel with both sensors functioning

Bad sensors alone would not prevent the fuel pump from coming on during cranking. In your case if the fuel pump doesn't come on during cranking AND there is no spark/fuel pulses this makes me think there is no power to the DME. Does the car have an alarm system. The way the factory alarm is implemented is to cut the +12V to the DME. This could be your issue.

First check is to feel if the ICV is vibrating with the key in the RUN position. This indicates the DME is alive and powered. The ICV is the silver can on top of the intake.

Also, try to listen for the faint click of the 1st stage of the DME relay under the drivers seat when you move they key to the RUN position. If the relay doesn't klick and the ICV isn't vibrating you have no power to the DME.

Let us know what you find,
Ingo
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1974 Targa 3.6, 2001 C4 (sold), 2019 GT3RS, 2000 ML430

I repair/rebuild Bosch CDI Boxes and Porsche Motronic DMEs
Porsche "Hammer" or Porsche PST2, PIWIS III - I can help!!
How about a NoBadDays DualChip for 964 or '95 993
Old 11-17-2013, 10:17 PM
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