Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

WTF?

Thread Tools
 
Search this Thread
 
Old Dec 5, 2013 | 11:26 PM
  #16  
dr bob's Avatar
dr bob
Chronic Tool Dropper
Lifetime Rennlist
Member
 
Joined: Oct 2001
Posts: 20,506
Likes: 564
From: Bend, Oregon
Default

If your ignition wires/caps/rotors are original, or are of dubious brand/quality, you'll get that ignition miss in one system that causes the car to burn down. We too often plod along with under-maintained ignition systems because the cars generally run OK in spite of the weaknesses. Add moisture to the high-tension side, as splash or even with excessive condensing humidity, and you have a recipe for problems. Water washing in through the edge of the hood drains down on the coils for instance, and any weakness in the coil-to-cap secondary wiring risks grounding the spark energy, as a for-instance.

In later cars ('89+), Porsche added a protection relay that senses temperature differences in the exhaust between cylinders with right-side ignition and left side ignition. The relay cuts off fuel to the cylinders that are colder, so it doesn't pass through unburned and overheat the catalysts. The factory got tired of replacing cars that burned, I'll speculate.

You were quite fortunate to get the car stopped before the undercoating and trans cooler lines caught fire. You can probably search this forum and other places for episodes that didn't turn out as well. Count your blessings! The car has been telling you that it wasn't doing well, down on power and running rough.
Reply
Old Dec 6, 2013 | 12:21 AM
  #17  
WallyP's Avatar
WallyP

Rennlist Member
Rennlist Site Sponsor

20 Year Member
 
Joined: Jun 2001
Posts: 6,469
Likes: 13
From: Ball Ground, GA
Default

Look at the inner edge of the fender above the ignition coils - there should be a short clip-on piece of black edging on the inner edge of the fender on each side. These are intended to prevent water from running down the inner flat part of the fender and draining down directly onto the ignition coils. High voltage and water are not a good combination...
Reply
Old Dec 6, 2013 | 01:21 PM
  #18  
James Bailey's Avatar
James Bailey
Addict
Lifetime Rennlist
Member
 
Joined: Feb 2009
Posts: 18,061
Likes: 10
Default

Originally Posted by dr bob
Count your blessings! The car has been telling you that it wasn't doing well, down on power and running rough.
Generally speaking when the car is talking to you it is best to listen....because it can get way worse !
Reply
Old Dec 7, 2013 | 12:27 AM
  #19  
Mrmerlin's Avatar
Mrmerlin
Team Owner
20 Year Member
 
Joined: May 2004
Posts: 31,150
Likes: 4,150
From: Philly PA
Default

I wont continue with the check the ignition system advice.

In the future its best to post something different than wtf for the thread titles,
for a few reasons,
It makes searching for your thread difficult , thus others may have a time finding a remedy from your post.

FWIW there was some mention that threads with this moniker would be deleted.

Oh dont keep running the engine like this with glowing cats,
as it will neatly ignite the body shutz ,
and or the ATF fluid that might be leaking from the lines above the cats.

This running condition has also been known to sever the drive shaft due to imbalances in the firing.
This is not limp home mode,
its shut me off before I fail totally......
Reply
Old Dec 8, 2013 | 08:54 PM
  #20  
awilli6's Avatar
awilli6
Thread Starter
Rennlist Member
15 Year Member
 
Joined: Oct 2010
Posts: 1,337
Likes: 68
From: Memphis, TN 1987 S4
Default Apologies

Mr Merlin,

Sorry for the vulgar title. It won't happen again. I can see how a search of the same problem would not yield results from my title. The only thing the car was doing was taking a second longer to turn over. I'm going to get into it in the morning and check all of your suggestions.
Reply
Old Dec 9, 2013 | 12:27 AM
  #21  
Mrmerlin's Avatar
Mrmerlin
Team Owner
20 Year Member
 
Joined: May 2004
Posts: 31,150
Likes: 4,150
From: Philly PA
Default

you can ask a mod to change your thread title so it can be found later.
Please post your results of your testing
Reply
Old Dec 10, 2013 | 12:49 AM
  #22  
awilli6's Avatar
awilli6
Thread Starter
Rennlist Member
15 Year Member
 
Joined: Oct 2010
Posts: 1,337
Likes: 68
From: Memphis, TN 1987 S4
Default Success

I got to evaluate the car today. The drivers side coil had corrosion. I cleaned all of it away and checked the rest of the system and all was well. The car started without having to give it gas and it was strong under load. It idled nice and smooth. I will replace that one wire where the corrosion was. I have the plastic strips but I guess the water still gets that side wet. Thanks for ya'lls help.
Reply




All times are GMT -3. The time now is 06:38 PM.