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Who knew a bad ground strap could cause so many problems!

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Who knew a bad ground strap could cause so many problems!

 
Old 05-05-2010, 11:14 PM
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Maleficio
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Default Who knew a bad ground strap could cause so many problems!

Hi, everyone.

I changed out the main engine ground strap today on my '82.

It fixed my cylinder misfire and overall imbalanced running problem. Engine is very balanced and harmonized now.

Overall voltage on the gauge is much higher and more steady.

But the best part is that my tach now works! No longer intermittent or not at all, it just works constantly. I was not looking forward to going into my pod. I just knew I'd cause other problems while trying to fix that one.

The engine starts on the first try now instead of second or third, too. That'll help my starter live longer.

If you'd like to read my comprehensive thread on the topic:
http://forums.pelicanparts.com/porsc...ml#post5335592
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Old 05-05-2010, 11:19 PM
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while your at it consider replacing the ground strap thats connected to the chassis and the battery, if your hatch area gets wet when you wash the car or when it rains then this strap will eventually corrode.
Glad you got your elex system figured out
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Old 05-05-2010, 11:27 PM
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Maleficio
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Originally Posted by Mrmerlin View Post
while your at it consider replacing the ground strap thats connected to the chassis and the battery, if your hatch area gets wet when you wash the car or when it rains then this strap will eventually corrode.
Glad you got your elex system figured out
Sorry, I forgot to mention that I changed it about an hour ago. Nothing dramatic happened, though.
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Old 05-06-2010, 12:20 AM
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Default What a great idea!

Wow! what a great idea! Checking the ground strap itself when checking the grounds!

I am torn between saying "told ya" and "your welcome"

http://forums.pelicanparts.com/porsc...ill-agree.html

You so owe me a beer...
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Old 05-06-2010, 12:28 AM
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Maleficio
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Originally Posted by SolReaver View Post
Wow! what a great idea! Checking the ground strap itself when checking the grounds!

I am torn between saying "told ya" and "your welcome"

http://forums.pelicanparts.com/porsc...ill-agree.html

You so owe me a beer...

I owe you several beers.

Next step is to locate all the other grounds and replace them, too. That alt strap looks like a real doozy! It apparently snakes upward and behind the timing belt cover?
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Old 05-06-2010, 12:32 AM
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Is there an advantage to replacing the ground strap versus cleaning the ground strap?
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Old 05-06-2010, 12:38 AM
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Originally Posted by syoo8 View Post
Is there an advantage to replacing the ground strap versus cleaning the ground strap?
I did clean my original ground strap yesterday, and it helped a little.

I just wanted to go one farther and replace it, and it paid off big time. My tach works. I'm so happy about that.
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Old 05-06-2010, 12:42 AM
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Default well grounded.

Aww....It isn't THAT bad. I replaced mine with a scrap jumper cable. (good gage copper AND cheap.)clean, soldier and re use the ends when possible. If you haven't seen it here are the places to go and things to do.

SY008: yea, corrosion creeps in the web to both ends.the ground straps themselves can cause ground problems. If yours tests bad (wiggle with ohmmeter) , replace it or fabricate one. I run extra grounds.
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Old 05-06-2010, 12:47 AM
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Calgary Ole
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I know a few R-Listers have had similar success with replacing the ground strap even though it looked okay. I think Landseer and Dean Fuller fixed issues with a new strap if IRC
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Old 05-06-2010, 01:04 AM
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I just did a quick search for ground wire kits, and didn't see anyone offering one comprehensive ground strap kit for a 928, but I did see one site selling a nice kit for a 3000 GT for $55.

I betcha a nice grounding kit for a 928 would be a big seller. I would buy one in a heartbeat simply because I now have first-hand experience of what a bad ground strap can do to the car.

http://www.3saudiofaq.com/topline/groundwirekit.html
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Old 05-06-2010, 01:10 AM
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Hey, SOLreaver, did i tell you that both old straps read perfect continuity? Reading out a strap will tell you nothing.
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Old 05-06-2010, 01:13 AM
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Originally Posted by Maleficio View Post
Hey, SOLreaver, did i tell you that both old straps read perfect continuity? Reading out a strap will tell you nothing.
Exactly.



BTW, that diagram doesn't show the strap Maleficio changed and isn't accurate for his car.

Posts 2 and 7 point out electrical stuff. Its a sticky for a reason. Dates from 2002! Much more within that sticky for us to read and re-read.

https://rennlist.com/forums/928-foru...irst-post.html

Last edited by Landseer; 05-06-2010 at 01:32 AM.
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Old 05-06-2010, 01:44 AM
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Did the ground strap appear to be corroded? Or was it perfectly fine looking? Just curious....
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Old 05-06-2010, 01:55 AM
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Originally Posted by Formula94lt1 View Post
Did the ground strap appear to be corroded? Or was it perfectly fine looking? Just curious....

It looked old and dirty. I unwound it and saturated the strands with strong solvent, and let it sit for 30 minutes. Wiped it down, then saturated it with contact cleaner, let it sit for ten minutes, then wiped it down and reinstalled. It did make a difference, but the effect didn't last.

I also scrubbed the contact points on the car.

I got in there again and sprayed it down with WD-40 and wiped it, and that seemed to restore the effect again. I figured that since the improvement wasn't lasting, that I should replace the strap.

I'm glad I did. My tach works!
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Old 05-06-2010, 02:11 AM
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If I were looking for a ground strap for the engine, I'd be looking at welding cable with crimped lugs and maybe lined shrink sleeves over the crimps. Welding cable is a lot more tolerant of vibration than most jumper cable materials, and it comes with relatively hi-temp insulation. A welding supply store will make the cables for you usually. Also-- you can buy 1ga battery cables in lug-to-lug configurations in many places that will also do the job. If you can get it at a marine store, they use tinned copper in the cables so less chnce of internal corrosion. As much as I love the original braided/open weave ground cables, there are better choices these days.
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