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lucittm lucittm is offline
Manassas, VA
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Join Date: Apr 2007
Posts: 1,211
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I wanted to include a picture so I had to remove my "quick" reply.

I checked my 1991 965 schematics and it shows the ignition delay relay coil is powered from the battery through the central electrics panel (fuse panel). There are no switches, relays, fuses, or sensors in this circuit. The relay has +12v all the time. You can check this by removing the relay and connecting a voltmeter between the relay terminals 2 or 3 (they are jumpered) and ground.

The ground side of the coil is connected directly to pin 8 of the Turbocharger Control Unit under the driver's seat (P/N 965-618-130-00). The connector may be loose and causing this issue.

Your relay should be energized when the key is in the "on" position and de-energized 5 seconds after the key is turned to the "off" position to burn off any remaining fuel in the cylinders that may have some fuel vapor left over when the engine was switched off.

I would begin by checking the connections and if they are good, you may have a faulty Turbocharger Control Unit.

One more thing, on my car the wire connecting the battery to the ignition delay relay under the central electrics panel burnt through because it was supposed to be a red 4.0mm wire and it was a .5mm wire. Yes, Porsche made a mistake in the wiring harness. Turn your fuse panel over and look for a thin burnt wire in the vicinity of "Black" coded connector. I have attached a "before" picture. If you need info on how to repair this PM me. (The burnt wire is just below the center of the picture and the red color looks brown.

1991 964 Polar Silver Metallic Turbo Coupe
Old 06-05-2010, 06:19 PM
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