|
|
|
|
| Author |
|
|
Registered
Join Date: Apr 2009
Location: Israel
Posts: 352
|
A little surprise and plug wires question
Hey all
It all started with the problem that I described in one of my older posts. The engine wouldn't go more then 4500 RPM. The feeling was that there is no fuel. most of the people told me that the problem must be in blocked fuel distributer. I went to check my entire fuel and ignition system just to be sure and there I was told that I am using a WRONG coil! the coil that should be installed must be with 0.5 ohm internal resistance. Mine was 1.5...I replaced the Coil and WOW!!! the engine has no problem in high RPM anymore!!!!  What I discovered is that I had MSD unit (Multiple Spark Discharge) installed in that car. This unit broke just before I bought the car so the previous owner installed some coil that he found...smart... To my question: Now I have 8.5mm plug wires. it is carbon wires - the one that is used with MSD. Is it ok to use those wires with the regular Coil? or should I replace the wires to copper wires? If so, any recommendations? Thanks!
__________________
Porsche 928S 4.7L 1980 European redhead
|
||
09-14-2009, 04:38 AM
|
|
|
Petie3rd
Join Date: Jul 2000
Location: Philly PA
Posts: 4,528
|
the wires you have should work OK run the engine at night and see if you find any fireflies jumping off of the wires.
If you do have sparks then i would go with returning the wires to original spec there should be a resistance of 3 ohm for each wire
__________________
^^^ Stan ^^^ 2019 BMW K1250 GS 2016 HD RK 1988 S4 Auto , Elfenbein Perlglanz, Pearl Gray 1982 5sp Met black and tan sport seats Last edited by Mrmerlin; 09-14-2009 at 08:49 AM.. |
||
|
09-14-2009, 05:37 AM
|
|
|
Moderator
|
Wow! Great fix Yoni. I would have never know, but we didn't know exactly what you had. I probably would have said the same about the Fuel Distributor since the exact same symptom happened to rjm65's OB. He took his apart his Fuel Distributor and cleaned it up and resealed and that worked for him. Merlin is right, check the wires for any sparklers at night. I'm gonna go with that they are probably fine. I actually like the larger diameter wires like you got now. I run those 8.5mm's on my Turbo Eclipse.
__________________
1981 Porsche 928 "Euro" Auto Gunsmoke Metallic Flat - Black Interior 1983 Porsche 928S "US" Auto Light Bronze (Copper) Metallic - Brown Interior **SOLD** 
|
||
|
09-14-2009, 08:44 AM
|
|
|
Architecture & Porsche's
Join Date: Jan 2006
Location: Austin, Texas
Posts: 3,189
|
spiral core wires are a no-no on the Porsche/Bosch/Beru wire configuration. On very strong ignition systems they work ok (Magnecor), but OE wires were solid stranded Bero with zero resistance: the resistors are in the disty cap connectors (1k) and in the spark plug terminals (3k). This is why I offer new leads for $99: to replace the 10 wires with new OE Beru wire & allows you to reuse your existing terminals which rarely (if ever) fail.
Mark
__________________
Porsche Club Racing National Scrutineer '89 Andial 951 '82 928R '74 911 RSR 3.6 |
||
|
09-14-2009, 09:49 AM
|
|
|
Registered
Join Date: Apr 2009
Location: Israel
Posts: 352
|
Yes, this fix also took me by surprise! I was ready to take the fuel distributer apart...
I also like the big diameter but I wonder about what Mark said here... Maybe before changing my Spiral wires I should check for my wire resistance thats should be about 3 ohm? or the spiral wires are 100% not good for this car? By the way, why 10? there are 8 wires for the cylinders and 1 for the coil...have you added me another cylinder that I am not aware of? 
__________________
Porsche 928S 4.7L 1980 European redhead
|
||
|
09-15-2009, 02:12 AM
|
|
|
Petie3rd
Join Date: Jul 2000
Location: Philly PA
Posts: 4,528
|
the 10 wires are for
8 spark plugs. 2 coils, if you only have one coil then your coil wire will be different depending on year 85/86 and S4 have 10 wires, as well as the 84 Euro with the early LH system
__________________
^^^ Stan ^^^ 2019 BMW K1250 GS 2016 HD RK 1988 S4 Auto , Elfenbein Perlglanz, Pearl Gray 1982 5sp Met black and tan sport seats |
||
|
09-15-2009, 04:00 AM
|
|
|
|
Registered
Join Date: Apr 2009
Location: Israel
Posts: 352
|
Mine is 80 European...I have only one coil there...should I have 2??
__________________
Porsche 928S 4.7L 1980 European redhead
|
||
|
09-15-2009, 07:22 AM
|
|
|
Moderator
|
Quote:
__________________
1981 Porsche 928 "Euro" Auto Gunsmoke Metallic Flat - Black Interior 1983 Porsche 928S "US" Auto Light Bronze (Copper) Metallic - Brown Interior **SOLD**
|
||
|
09-15-2009, 07:52 AM
|
|
|
Petie3rd
Join Date: Jul 2000
Location: Philly PA
Posts: 4,528
|
no you should only have one coil wire on your 80
The 84 /85 Euro has 2 since it also has twin distributors and an early LH injection system
__________________
^^^ Stan ^^^ 2019 BMW K1250 GS 2016 HD RK 1988 S4 Auto , Elfenbein Perlglanz, Pearl Gray 1982 5sp Met black and tan sport seats |
||
|
09-15-2009, 08:00 AM
|
|
|
Architecture & Porsche's
Join Date: Jan 2006
Location: Austin, Texas
Posts: 3,189
|
y my bad, I assumed it was a 32v.
The Ohm resistance values are cast into the rubber Beru boots: 3k, 1k, etc.  Within 10% is considered good by Beru.
__________________
Porsche Club Racing National Scrutineer '89 Andial 951 '82 928R '74 911 RSR 3.6 |
||
|
09-15-2009, 08:14 AM
|
|
|
Registered
Join Date: Apr 2009
Location: Israel
Posts: 352
|
I just found a Kingborne wire set 7mm...is it something suitable?
I dont think I can reuse my current wire terminals since they are installed on 8.5 wires most of the wires are about 7-8mm  is there any recommended wire diameter that is recommended?
__________________
Porsche 928S 4.7L 1980 European redhead
|
||
|
09-16-2009, 04:43 AM
|
|
|
Architecture & Porsche's
Join Date: Jan 2006
Location: Austin, Texas
Posts: 3,189
|
Kingsborne is good stuff: can't go wrong there. OEM Beru solid core wire is 7mm OD: If it's good enough for Porsche, Mercedes, Audi...
Mark
__________________
Porsche Club Racing National Scrutineer '89 Andial 951 '82 928R '74 911 RSR 3.6 |
||
|
09-16-2009, 06:37 AM
|
|
|
Registered
Join Date: Apr 2009
Location: Israel
Posts: 352
|
Funny thing...I just sent an email to "MSD ignition" asking them if I can use their carbon spiral wires on Porsche 928 with regular BOSCH components and they said "yes"
 Today this is exactly what I have on my car...MSD wires with regular BOSCH components and it does work but I understood (also from here) that it is not recommended due to higher wire resistance...what should I do?
__________________
Porsche 928S 4.7L 1980 European redhead
|
||
|
09-17-2009, 01:36 AM
|
|
|
Architecture & Porsche's
Join Date: Jan 2006
Location: Austin, Texas
Posts: 3,189
|
I had continuing ignition/dyno/hp issues, stumbling that would never go away, using MSD wire with OEM Beru connectors. Only an OEM set fixed the issue. Very finicky systems. So, if your car is running great, no stubling, idling, missing, cutting-out on top issues, let it be. Porsche/Beru/Bosch engineered the ignition systems so that each cylinder was equipped with the same resistance wire (0 + 1k at the disty & 3k at the spark plug) for even spark distribution. Mark
__________________
Porsche Club Racing National Scrutineer '89 Andial 951 '82 928R '74 911 RSR 3.6 |
||
|
09-17-2009, 06:41 AM
|
|
|
Registered
Join Date: Apr 2009
Location: Israel
Posts: 352
|
My MSD wires has MSD connectors since it was part of a complete MSD set.
What I have is problem in Idling...I cant make it go below 1000 RPM. If I try to adjust it then it starts to stumble...If I open my A/C it stalls. my CO levels are high (about 6%) so I thought maybe the wires could be the problem. Maybe it is the reason for that. I think that I will put the OE wires and hope it will solve that problem.
__________________
Porsche 928S 4.7L 1980 European redhead
|
||
|
09-17-2009, 07:58 AM
|
|
|
Architecture & Porsche's
Join Date: Jan 2006
Location: Austin, Texas
Posts: 3,189
|
Your to the point where you should start considering that the MSD is contributing to your issues.
Do you have an original/old set of wires for your car? if you do, unscrew the ends on both ends. I'll make you a set to test: if they work & you want to buy them (assuming my wires fit both threaded ends of your existing terminals) , great, if not you can send them back. Mark
__________________
Porsche Club Racing National Scrutineer '89 Andial 951 '82 928R '74 911 RSR 3.6 |
||
|
09-17-2009, 08:04 AM
|
|
|
Network Native
Join Date: Jan 2007
Location: SoCal
Posts: 10,349
|
Getting rid of the MSD often fixes otherwise hard to explain problems. Not just Porsche, same is true for my Mustang. If it works fine for you, great, if not, reverting to stock is first thing I suggest.
|
||
|
09-17-2009, 10:40 AM
|
|
|
Architecture & Porsche's
Join Date: Jan 2006
Location: Austin, Texas
Posts: 3,189
|
I had a hard miss issue on my 951S where someone put an MSD on it: removed it, issue is gone. You never know.
Mark
__________________
Porsche Club Racing National Scrutineer '89 Andial 951 '82 928R '74 911 RSR 3.6 |
||
|
09-17-2009, 11:00 AM
|
|
|
Banned
Join Date: Mar 2007
Location: Ft.Lauderdale, FLORIDA
Posts: 2,813
|
This is slightly off-topic, but I have the Nology wires on my '85 S2 and though they really look cool....they do nothing more than what a cheap set of wires can do for you. Also, they have a bunch of "grounding" wires [?] that need to either be trimmed off or secured somewhere.
If you want the look, buy them. Otherwise.... N |
||
|
09-17-2009, 12:12 PM
|
|
|
Architecture & Porsche's
Join Date: Jan 2006
Location: Austin, Texas
Posts: 3,189
|
I used to sell Nology wires when I had my performance shop some 10 years ago: neat "looking" product, no real performance gain, and unfortunately, all their wire sets were made about 4-6" too long...+ the grounding straps.
I had to warrant more than a few broken leads...not the best quality. These are Nology's on my 951S from 10+ years ago Mark 
__________________
Porsche Club Racing National Scrutineer '89 Andial 951 '82 928R '74 911 RSR 3.6 |
||
|
09-17-2009, 01:27 PM
|
|
