3rd break down, still a mystery
Thread Starter
Three Wheelin'
Joined: Jan 2007
Posts: 1,748
Likes: 33
From: London UK & Paris FR
3rd break down, still a mystery
Hi guys,
I break down 3 times with in a month, always the same way, slowing and shifting down, the car just shuts itself down, as if I had turn off the key,
We check relays, changed a faulty coil, ( both coils were renewed 3 months ago ) fit a new crank sensor , removed the alarm (10 years old) but we can't find the problem....I break down the day before yesterday exactly the same way, now I am so worried to drive the car....
Any ideas , as anyone as experience this problem.....
Thanks
Konstantin
I break down 3 times with in a month, always the same way, slowing and shifting down, the car just shuts itself down, as if I had turn off the key,
We check relays, changed a faulty coil, ( both coils were renewed 3 months ago ) fit a new crank sensor , removed the alarm (10 years old) but we can't find the problem....I break down the day before yesterday exactly the same way, now I am so worried to drive the car....
Any ideas , as anyone as experience this problem.....
Thanks
Konstantin
Addict
Rennlist Member
Rennlist Member
Joined: May 2002
Posts: 3,605
Likes: 4
From: Bologna, Italy
Hi Konstantin,
Are you able to start the car normally again each time? If so, this sounds typical of the stalling issues experienced with cars that have the RS LWF fitted. When changing down, the revs sometimes drop too quickly for the DME to be able to stop the engine from stalling. On mine, it doesn't happen all the time, but when it does, it only happens when the air con is turned on. (Previous to me having my air con re-gassed it never did it, so I can only assume a full system puts more load on the engine and thus makes the revs drop quicker?).
If it's the same for your car, perhaps turn the air con off and see if it still happens?
Andrew
Are you able to start the car normally again each time? If so, this sounds typical of the stalling issues experienced with cars that have the RS LWF fitted. When changing down, the revs sometimes drop too quickly for the DME to be able to stop the engine from stalling. On mine, it doesn't happen all the time, but when it does, it only happens when the air con is turned on. (Previous to me having my air con re-gassed it never did it, so I can only assume a full system puts more load on the engine and thus makes the revs drop quicker?).
If it's the same for your car, perhaps turn the air con off and see if it still happens?
Andrew
Rennlist Member
Joined: Sep 2009
Posts: 8,687
Likes: 785
From: Canada & the Alps
Burning Brakes
Joined: Oct 2009
Posts: 1,111
Likes: 243
From: Mainhatten / Frankfurt
Ground cable from battery an motor renewed? Mine had similar issues, two years ago (happend only when driving slow but if it happend, it felt like turn key "off").
I changed both cables and the problems were gone.... It was a 20€ fix...
I changed both cables and the problems were gone.... It was a 20€ fix...
Three Wheelin'
Joined: Mar 2010
Posts: 1,400
Likes: 39
From: McKinney, Texas
When you say "checked relays", did you actually change the DME relay?
I had your symptoms and it was a bad DME relay. I always carry a spare. The next time it stops, immediately change the relay and see if it restarts.
I had your symptoms and it was a bad DME relay. I always carry a spare. The next time it stops, immediately change the relay and see if it restarts.
RL Technical Advisor
Joined: May 2001
Posts: 11,870
Likes: 75
From: Portland Oregon
Since you have an aftermarket ECU, I'd also recommend a very thorough check of the ECU's connector and wiring into the main harness.
I've seen quite a few problems over the past 20+ years with this sort of thing.
I've seen quite a few problems over the past 20+ years with this sort of thing.
Trending Topics
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
Six Genius Porsche-Themed Gifts That'll Make Any Dad or Grad Smile
Joe Kucinski
10 Used Porsches Are Selling for Way Too Cheap
Joe Kucinski
Tuner Is Converting Porsche 911s Into Shooting Brakes
Verdad Gallardo
This Coachbuilt Creation Is A Modern Take on the Legendary Porsche 917
Verdad Gallardo
Is This Convertible Cayenne A Steal, Or A Returnless Investment?
Verdad Gallardo
10 Best Non-Flat Six Porsches You Can Buy For Under $100K
Joe Kucinski
Porsche's Top 5 Most Questionable Naming Decisions
Verdad Gallardo
Pogea Racing's 964 Porsche 911 Reimagination Stands Out in a Crowded Field
Verdad Gallardo
6 Convertible Top MYTHS Most People Don't Understand!
Michael S. Palmer
Pro
Joined: Jun 2009
Posts: 748
Likes: 8
From: Dayton, OH
Same here. Changed the battery ground strap and all has been good.
Thread Starter
Three Wheelin'
Joined: Jan 2007
Posts: 1,748
Likes: 33
From: London UK & Paris FR
Hi Guys,
Thanks a lot for your suggestions,
I will check both battery cables,
when brake down the small Odyssey race batterie still crank very well the engine...
The connection, adapter loom to the ECU is also an option, I will take bucket out to check it.
Fuel, is find we also changed the fuel filter, it's really dying as if the key was turned off....
Eric,
I think the garage change one of the ingnition control units when renew both coils a month ago, do you run with out it ? It's well hot at the moment here in south of France 33/35 Celsius
I had renewed the DME , had a spare one ( was in the glove box from previous owner) but I think in case this is faulty I will change it with new one...
This is a real nightmare , as I may fix it with out knowing until I break down, I was thinking going around my house until it does it again ......
Will let you know if I found something,
Konstantin
Thanks a lot for your suggestions,
I will check both battery cables,
when brake down the small Odyssey race batterie still crank very well the engine...
The connection, adapter loom to the ECU is also an option, I will take bucket out to check it.
Fuel, is find we also changed the fuel filter, it's really dying as if the key was turned off....
Eric,
I think the garage change one of the ingnition control units when renew both coils a month ago, do you run with out it ? It's well hot at the moment here in south of France 33/35 Celsius
I had renewed the DME , had a spare one ( was in the glove box from previous owner) but I think in case this is faulty I will change it with new one...
This is a real nightmare , as I may fix it with out knowing until I break down, I was thinking going around my house until it does it again ......
Will let you know if I found something,
Konstantin
Three Wheelin'
Joined: Mar 2009
Posts: 1,544
Likes: 5
From: Brisbane, Australia
Konstantin,
The ignition control units can get a little erratic with old age. I have seen cases before where they have failed on the track and then come back to life when they cool. If I recall they are normally mounted to a heat sink (aluminium plate) using special heat conductive adhesive. If the wrong adhesive (or no adhesive) is used on reinstall they will potentially fail quickly. A further possibility is the replacement is faulty (especially if it is aftermarket/non Bosch).
Good luck.
The ignition control units can get a little erratic with old age. I have seen cases before where they have failed on the track and then come back to life when they cool. If I recall they are normally mounted to a heat sink (aluminium plate) using special heat conductive adhesive. If the wrong adhesive (or no adhesive) is used on reinstall they will potentially fail quickly. A further possibility is the replacement is faulty (especially if it is aftermarket/non Bosch).
Good luck.
Thread Starter
Three Wheelin'
Joined: Jan 2007
Posts: 1,748
Likes: 33
From: London UK & Paris FR
Hi guys , just a update, we went through everything, and it seams to be the DME, witch we thought we tested and was out of the way, then had a problem with crank sensor failure & a coil.....
I hope it s nothing else, I getting a little it paranoid there....
Bottom line is the DME relay could fail even in your glove box, it 's only guaranty to work by Porsche for 5 years I think...best is to keep one in the glove box but also I will make up some wires to replace the DME , knowing this will certainly work with the downside of the pump fuel working all the time, so needed the wires or batterie to be disconnected when stoping the car....
Crossed fingers....
Thanks for your comments
Konstantin
I hope it s nothing else, I getting a little it paranoid there....
Bottom line is the DME relay could fail even in your glove box, it 's only guaranty to work by Porsche for 5 years I think...best is to keep one in the glove box but also I will make up some wires to replace the DME , knowing this will certainly work with the downside of the pump fuel working all the time, so needed the wires or batterie to be disconnected when stoping the car....
Crossed fingers....
Thanks for your comments
Konstantin
