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Registered
Join Date: Jul 2000
Location: Windsor, Ont/ Detroit, MI
Posts: 189
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No Spark issue HELP 8V 2.5L 924S
I have a 924S that is giving me some trouble. I have a signal processed from the DME since the Injectors are firing as required and the DME relay and fuel pump is working fine... The fuel system is all confirmed.
For spark, I replaced the coil with a known good one and replaced the cap and rotor but it seems the non-spark is being caused by a fuse/Computer/loose connection under the dash (where all this is located on the 924S.) Any suggestions would be a great help. It seems I can get it started if wiggle wires/tap on Computer and roll fuses under the dash. But it will cut out and quit when it feels like it. Any advice or help would be appreciated. Aaron atsudds@cogeco.ca |
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07-11-2006, 04:30 AM
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Certified Rennwerker
Join Date: Oct 2002
Location: Kansas
Posts: 1,906
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Check the inside of the computer for soldering issues at the ribbon(grey wire loom).
Dal
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PCA " I've been everywhere, done everything......just can't remember any of it!" 
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07-11-2006, 04:43 AM
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Registered
Join Date: Jul 2000
Location: Windsor, Ont/ Detroit, MI
Posts: 189
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Is it a common issue for the DME to fail... If so I'll try swapping it with another one.
Aaron |
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07-11-2006, 04:58 AM
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Certified Rennwerker
Join Date: Oct 2002
Location: Kansas
Posts: 1,906
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Not often but does. The ribbon is a known area to break.
Dal
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PCA " I've been everywhere, done everything......just can't remember any of it!"
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07-11-2006, 05:43 AM
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Registered
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To check that it is a DME problem rather that a wiring problem run a jumper from the batteries positive terminal to terminal #15 (black wire) on the coil and see it it will spark.
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Hugh - So Cal 83 944 Driver Person NOT a 'real' Porsche -- Its Better!!!! When was the last time you changed your timing and balance belts and/or cam chain and tensioner? New Users please add your car's year and model to your signature line! Never break more than you fix! |
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07-11-2006, 08:00 AM
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Registered
Join Date: Jul 2000
Location: Windsor, Ont/ Detroit, MI
Posts: 189
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SoCal, can I run a jumper and drive it that way in case of emergency?
Does the DME do anything more than provide a 12V supply to the Coil? Like I said, the injector pulse seems to be firing ok. Thanks, Aaron |
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07-11-2006, 09:04 AM
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Registered
Join Date: Aug 2001
Location: Brighton UK since 11/2012
Posts: 3,170
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The DME provides the ground and allows the system to run. Sounds like you need to both thoroughly check the wiring and if ok, substitute a DME.
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From November 2012; Precision Porsche Specialist Sussex UK, +44 (0)1825-721-205 2001-2012 Gerber Motorsport Inc. 206-352-6911 07.15.06 1996 Ducati 900SP. Suprisingly enough, it's red 08.16.09 1999 Kawasaki ZRX1100. Green. |
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07-11-2006, 09:19 AM
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Registered
Join Date: Jul 2000
Location: Windsor, Ont/ Detroit, MI
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Swapped the computer with a known good one... so far so good...
I'll try and fix the old one. Aaron |
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07-11-2006, 11:04 AM
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Registered
Join Date: May 2005
Location: Brentwood, Tennessee
Posts: 385
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If the problem recurs, it may be the ignition switch. I had a similar experience with my 924S and wound up wiring a toggle switch across two of the ignition switch poles. (I was at Sebring for a PCA race.) Five years later, the toggle switch still works.
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07-11-2006, 12:39 PM
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Registered
Join Date: Jul 2000
Location: Windsor, Ont/ Detroit, MI
Posts: 189
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DME had obvious cold soldier joints on the power transistors. Must have been the problem....
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07-12-2006, 04:33 AM
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1983 Porsche 944 2.5 liter
