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check the pressure from the system. Maybe a faulty regulator or a fuel pump that is going bad.
Ritchie owner of a '92 Coupe Tiptronic with the following standardoptions: C00, 030, 139, 249, 258, 340, 383, 387, 403, 418, 454, 490, 494, 567, 573, 650, 690, 14951
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This is a sure sign of a failing DME Relay. Entirely common occurance, known weak point. Most of us keep a spare in the glove compartment (costs about $30).
Regards,
Jay
“Faster, Faster, until the thrill of speed overcomes the fear of death.” - Hunter S. Thompson
"I couldn't find the sports car of my dreams, so I built it myself." ~Dr. Ferdinand Porsche
"968Forums, a quaint little drinking community with a serious horsepower problem"
"Life's journey is not to arrive at the grave safely in a well-preserved body, but rather to skid in sideways, totally worn-out, shouting, 'Holy sh*t! What a ride!'"- Unknown
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If there is a whine from the back in according to a variarity of sound (pump revs is not stabil) , check if there is 12 volt or more at the pump available. Maybe there is a connector going bad underside the car. This can work as a resistor. Or the DME is going bad.
Ritchie owner of a '92 Coupe Tiptronic with the following standardoptions: C00, 030, 139, 249, 258, 340, 383, 387, 403, 418, 454, 490, 494, 567, 573, 650, 690, 14951
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<!--quoteo(post=78342:date=Aug 20 2009, 11:48 PM:name=matti)-->QUOTE (matti @ Aug 20 2009, 11:48 PM)
<{POST_SNAPBACK}><!--quotec-->Good point. Whining sound is not there always, which is a bit strange...
I swapped to new DME a year ago, just to play safe, and have the old one in glovebox. BTW, how does the faulty FPR (fuel pressure regulator) act, gives too low pressure or what?<!--QuoteEnd--><!--QuoteEEnd-->
Hot start problems are often the coil or the ignition module. I would check to see if you have a good, strong spark using a spark checker or seeing if the spark will jump a 1cm air gap when it is not starting.
A bad FPR will sometimes leak gas into the vacuum side, or it will stick and not adjust properly. The spring can also get weak. Some people hammer on them with a socket of the correct size to crush them a bit, if they are running low or they want a cheater way to raise fuel pressure in a stock racing class. I personally do not think you would have a fuel pressure problem that is causing this, you would have other problems, perhaps black plugs, etc.
Anyway when it is not starting check for spark, check the plugs for gas or fouling, and look for clues. You can also try thumping the DME or at least stomping on the passenger's footwell. It could also be an alarm system problem or even an ignition switch. If you can check a few things and let us know, that'd help.
-Joel.
Joel Frahm
1992 968 Cabrio Black/Cashmere
1994 968 Cabrio Iris Blue/Lt. Grey - Supercharged
1987 928S4 Diamondblau/Blue
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My symptoms are exactly the same as Cloud's. Sometimes it'll start without issues when warm/hot. Other times it acts as if it's laughing at me saying... "I'm not starting dude, forget about it, I'm not starting. It's too freaking hot, I'm not starting. No really, crank away sucker. I'm not starting".
Normally if I crack the throttle about 1/2 to full for just a second or two while cranking, it'll start when hot. "Normally". But day by day it still seems like I'm cranking longer than what you would consider "normal" in most other cars.
I have had times when it simply didn't want to fire up. After waiting a minute or so, the crank-with-throttle-open-method works. Normally.
I've got to figure this out.
My 1998 Explorer fires right the heck up the moment you just bump the ignition switch.
Frustrating AND embarassing for a Porsche owner to say the least.
Dan
'95 968 Coupe
"Dream like you'll live forever... Live like you'll die today"
James Dean
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under all conditions my 968 fires right up! even with a poor battery. . Maybe your idle stabilizer system is a bit faulty?
Ritchie owner of a '92 Coupe Tiptronic with the following standardoptions: C00, 030, 139, 249, 258, 340, 383, 387, 403, 418, 454, 490, 494, 567, 573, 650, 690, 14951
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<!--quoteo(post=78450:date=Aug 23 2009, 01:22 AM:name=flash)-->QUOTE (flash @ Aug 23 2009, 01:22 AM)
<{POST_SNAPBACK}><!--quotec-->i am having trouble finding the specs on the coil - the only bosch black coil specs i can find are:
100 turns
primary 3.0 ohm
secondary 9.83 ohm<!--QuoteEnd--><!--QuoteEEnd-->
Are all coils equal, or are some more equal than others?
Johann van Biljon
'60 Aetna Blue 356B T5 Coupe
'94 Midnight Blue 968 Coupe - No Sunroof, RS Barn Stage 1 Chip, Airbox mod, RS Barn Cat-back, NGK irridium spark plugs - Sold
'92 Signal Red 964 Carrera 4 - Sold
'84 Burgundy 911 Carrera 3.2 Cabriolet - Sold
'90 Silver 944 Turbo S with M030 and limited slip diff - Sold
'76 Silver 911 Carrera 3.0 Targa - Sold
'79 Silver 924 5 speed - Sold
