Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #31  
Old 01-19-2014, 11:12 PM
Registered User
 
Join Date: Oct 2007
Location: Greater Metropolitan Beaverdam VA
Posts: 2,124
Pete's opinion

Benz designed resistance into the wiring/terminals. The use of resistor plugs upsets the ignition equation and will result in suboptimal efficiency.

My solution, eliminate spark plugs altogether.
Reply With Quote
  #32  
Old 01-19-2014, 11:21 PM
JamesDean's Avatar
Electrical Engineer
 
Join Date: Apr 2005
Location: NE Ohio
Posts: 5,016
Quote:
Originally Posted by lsmalley View Post
Its a PITA trying to find readily available NR plugs. I have a cousin that lives in Germany and works for the post office, but still, I don't want to have to wait for 2 weeks to get plugs. I was under the impression that you can unscrew the metal tip that screws into the ceramic portion of the plug and there is the resistor inside. So I was thinking you unscrew the tip, take out the resistor through the opening, insert an equal piece of legnth of copper (maybe a cut coat hanger) for continuity, and screw the cap back on.
Denso's T20EP-U's are pretty easy to obtain. They cost $2/each last time I bought some. I bought 12 last time around so I'd have some for the next change. I wouldn't go through all that extra stuff.
__________________
Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

82 300SD 145k
82 300SD 265k
87 420SEL 230k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k
Reply With Quote
  #33  
Old 01-20-2014, 10:50 AM
oldsinner111's Avatar
love all animals
 
Join Date: Nov 2008
Location: bristol,tn
Posts: 5,231
I run denso 5061 spark plugs,there are like the 3 groundstrap plugs bosch makes,that came with my car
__________________
veteran,mother german,born in stuttgart,shoot a racist for Isis
Reply With Quote
  #34  
Old 01-20-2014, 10:53 AM
JamesDean's Avatar
Electrical Engineer
 
Join Date: Apr 2005
Location: NE Ohio
Posts: 5,016
Quote:
Originally Posted by oldsinner111 View Post
I run denso 5061 spark plugs,there are like the 3 groundstrap plugs bosch makes,that came with my car
These are also resistor plugs. Your car has a different ignition system than the OP's 190E 2.6, it might not suffer the same ill effects.

Quote:
Denso Spark Plug Multi-ground electrodes specified by engine manufacurer for unusual combustion chamber design, click on Multi-ground for more info. Copper core for better thermal conductivity. Machine rolled threads to reduce cross-threading and seizing . The plug insulator is constructed of purified alumina powder for extreme stress with 5 ribs to prevent flashover. Technical Specifications - 14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Projected Tip, Triple Ground Electrodes, Removable Terminal Nut, Semi Surface Gap, .040" Gap
__________________
Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

82 300SD 145k
82 300SD 265k
87 420SEL 230k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k
Reply With Quote
  #35  
Old 01-20-2014, 12:46 PM
Registered User
 
Join Date: May 2009
Posts: 273
Quote:
Originally Posted by rocky raccoon View Post
..., eliminate spark plugs altogether.
How are you going to light the fuel? With a match?

Someone said that it's best to rely on your MB dealer selling you the right plugs. NO!

My MB dealer sold me 2 lots of resistor plugs for a total of 200 Euro before I took the matter in hand and put in non-resistor Bosch plugs. Result: more even idling and eliminated misfire. This on a 1991 M104.980 engine.

I now get Beru or NGK for about 2 Euro each and all is well. MB in my neck of the woods (France) can be utterly clueless on older car issues.

It is most important that all HT components on my engine (and similar) are of the highest quality and in perfect condition. For me, this means MB for everything apart from plugs. Failing that, Beru or Bosch caps and rotors. NOTHING else, in my opinion.

The best to all.

RayH
Reply With Quote
  #36  
Old 01-20-2014, 02:36 PM
jhodg5ck's Avatar
Registered User
 
Join Date: Feb 2004
Location: Atlanta, GA
Posts: 1,395
You can always find the NR plugs @ the dealer...if you joing MBCA you get wholesale pricing. No fuss/no muss!

Or, order a bunch off of parts.com and request a shipping quote to keep it reasonable!

Jonathan
__________________
Blue Ridge Mercedes
Jonathan Hodgman
http://www.blueridgemb.com/
Enthusiast Service, Restoration & Tuning.
Follow Us on Facebook!
Located in the Atlanta area
Specializing in all pre and post merger AMG's including Hammers and DOHC M117 engines.
Mercedes Repair Atlanta
Reply With Quote
  #37  
Old 01-21-2014, 07:29 PM
Luxury Hooptie Enthusiast
 
Join Date: Aug 2010
Location: Screwston, TX
Posts: 333
What is all this $4-5 plug bull**** I keep hearing? You can get Bosch non-resistor plugs on the web for under $2. I paid $1.50 each from the Auto parts Haus that's in AZ.
__________________
Current:
1994 E320, Brilliantsilber 191k
1982 300D, Silberblau under a blue repaint 256k

RIP:
1995 E300D Polarweiss, 287k
1995 E320 Polarweiss, 126k
Reply With Quote
  #38  
Old 01-21-2014, 07:39 PM
jhodg5ck's Avatar
Registered User
 
Join Date: Feb 2004
Location: Atlanta, GA
Posts: 1,395
If you Read fully you'll note that I say Worst case scenario you can source the Correct/Proper plug from the dealer for said 4-5$

Not all NR bosch plugs are available on the aftermarket stateside.
__________________
Blue Ridge Mercedes
Jonathan Hodgman
http://www.blueridgemb.com/
Enthusiast Service, Restoration & Tuning.
Follow Us on Facebook!
Located in the Atlanta area
Specializing in all pre and post merger AMG's including Hammers and DOHC M117 engines.
Mercedes Repair Atlanta
Reply With Quote
  #39  
Old 01-21-2014, 07:56 PM
lsmalley's Avatar
Registered User
 
Join Date: Oct 2006
Location: California
Posts: 1,918
Quote:
Originally Posted by okto View Post
What is all this $4-5 plug bull**** I keep hearing? You can get Bosch non-resistor plugs on the web for under $2. I paid $1.50 each from the Auto parts Haus that's in AZ.
Then you either got lucky, ordered the plugs several years ago, or you did not read the label correctly. That website in AZ offers resistor type plugs. Also, keep in mind I'm referring to the Bosch H9DC/H9DC0 for the m103 engine. If you go back go back to the website you will see that they offer H"R"9DC plugs.
__________________

1990 190E 2.6L
Reply With Quote
  #40  
Old 01-21-2014, 10:07 PM
Moderator
 
Join Date: Dec 2001
Location: Southern California, U.S.A.
Posts: 8,538
Reading this thread jogged my memory of this great post by mercmad6.3:

"He might not have,but I have had plenty of experience dealing with older Mercedes wrongly fitted with carbon string leads and resistor plugs. Mercedes Do not need suppressor leads as from 1937 on wards you could buy suppressed or non suppressed distributor and plug terminals for this very purpose. From the mid 1950's nearly all gas Mercedes came equipped with the suppressor plug terminals (5kohms) . From the 1970's all came with a resistor in the rotor (always check old rotors )
and then the distributor terminals as standard. Right up until the 1990's all Mercedes still had solid core leads,and for a very good reason. it is reliable and it is the best. The resistor plug terminals slow the spark down from a bright instant flash to a slow(relatively) arc almost. This Promotes better combustion . Use a carbon string lead ,which are nearly always offering too much resistance and you are asking for unreliability ,mostly hard starts and all that it leads too."

Here's then whole thread:

http://www.peachparts.com/shopforum/vintage-mercedes/349465-pertronix-radio-interference-mystery-solved.html
__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".
Reply With Quote
  #41  
Old 01-22-2014, 10:56 AM
1991300SEL's Avatar
Registered User
 
Join Date: May 2003
Posts: 545
Years back when it was made known that the Bosch NR plugs were going off market, I bought several sets. I'm covered.

Similar situation occurred with R-12. Did you load up before it was no longer available without license and gouge pricing?
__________________
'91 300-SEL
Reply With Quote
  #42  
Old 01-26-2014, 05:48 AM
lsmalley's Avatar
Registered User
 
Join Date: Oct 2006
Location: California
Posts: 1,918
Ok, well I did it. I converted resistor plugs into non-resistors. when I explained it it seems like a lot, but the reality its that it takes only about 5-10 mins for all the plugs and you're done. Unscrew the tip, take out resistor, put in a core, screw the cap back on.
Resistor spark plug converted into a non-resistor spark plug (with pictures)
__________________

1990 190E 2.6L

Last edited by lsmalley; 01-26-2014 at 11:24 AM. Reason: link added
Reply With Quote
  #43  
Old 01-26-2014, 12:48 PM
Graham's Avatar
Registered User
 
Join Date: Nov 2004
Location: Ontario, Canada
Posts: 3,396
Quote:
Originally Posted by lsmalley View Post
Ok, well I did it. I converted resistor plugs into non-resistors. when I explained it it seems like a lot, but the reality its that it takes only about 5-10 mins for all the plugs and you're done. Unscrew the tip, take out resistor, put in a core, screw the cap back on.
Resistor spark plug converted into a non-resistor spark plug (with pictures)
Just wanted to let you know that I borrowed one of your pics in this post:

Pertronix radio interference...mystery solved.

My post suggests that there is no need for non-resistor plugs if using the current Bosch or in fact almost all aftermarket wire sets on our old cars.
__________________
Graham
85 300D,72 350SL, 98 E320, Outback 2.5
Reply With Quote
  #44  
Old 10-08-2014, 10:10 AM
oldsinner111's Avatar
love all animals
 
Join Date: Nov 2008
Location: bristol,tn
Posts: 5,231
I read today at NGK website that resistor plugs,are better for computer controlled cars.It says the noise(dirty voltage) from non resistors are damaging to the computers.
__________________
veteran,mother german,born in stuttgart,shoot a racist for Isis
Reply With Quote
  #45  
Old 10-09-2014, 09:56 PM
Registered User
 
Join Date: Feb 2013
Location: South carolina
Posts: 47
Looking through plug part numbers at Advance for my '88 420 it has a Bosch P/N 7905 listed. It's a Bosch Super Plus Copper Core plug. My question is... is this a non-resistor or resistor plug. The new P/N W8DC would be for the non-resistor. If there's a R ,as in WR, in the Bosch p/n would mean resistor correct?
__________________
1983 300SD
1988 420SEL
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 06:20 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page