Help finding non-resistor plugs - PeachParts Mercedes-Benz Forum

mbzman · #1 09-17-2010, 01:26 AM

I can't seem to find any non-resistor plugs here. The dealer's supply has disappeared and most auto parts stores simply don't know the difference! I found some NGK BP5EFS from the UK. Will they work okay in a North American engine or will they have a different heat rating?

http://cgi.ebay.ca/3712-BP5EFS-NGK-SPARK-PLUG-X-1-LOW-PRICES-/160426164751?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item255a25020f#ht_3367wt_991

mbdoc · #2 09-17-2010, 08:16 AM

Why are you worried about the replacement Bosch (slightly) resistor spark plugs?

They have and cause ZERO issues.

RBYCC · #3 09-17-2010, 09:35 AM

NGK BP5EFS will give great performance in the M103-12V.
I run one step colder BP6EFS in my M103-12V twin turbo.

Ed A.

sptt · #4 09-17-2010, 11:05 AM

I bought some from Autozone (local auto parts store) here for 1.99 each...Autolites. Car loves them! I'm sure the Bosch copper or NGKs will be even better. Don't get the platinum or irridium stuff. I tried those and car ran like crap. Champion coppers might even work. I just don't know how long they'll last and make sure you gap them correctly.

ps2cho · #5 09-17-2010, 12:59 PM

Get them from the dealer they are $2.60 each iirc.

mbzman · #6 09-17-2010, 01:57 PM

Quote:

Originally Posted by ps2cho

Get them from the dealer they are $2.60 each iirc.

None at local dealerships. H9DC0 has been superseded with HR9DCO (which is what I'm using now).

Gilly · #7 09-17-2010, 04:53 PM

Are the HR's working OK for you or is there some perceived problem??

mak · #8 09-17-2010, 05:48 PM

i had installed BERU low resistance ignition leads, and with these i use the readily available resister plugs without any detrimental effect to performance.
.
Very old ignition leads become conductive around the metal end cap area and most likely give the poor performance attributed to the resister plugs
mak

mbzman · #9 09-17-2010, 08:09 PM

I have a uneven idle that I've been trying to figure out. You can hear and feel the engine surge while idling. I did install a new set of Bosch HR9DC plugs and Beru wires last year to no effect. Can resistor plugs make that much of a difference?

ps2cho · #10 09-17-2010, 08:25 PM

Quote:

Originally Posted by mbzman

None at local dealerships. H9DC0 has been superseded with HR9DCO (which is what I'm using now).

Just noticed you are from Canada...

In the USA they are still available for future US researchers.

Denso T20EP-U are non-resistor and may be easier to find.

mak · #11 09-18-2010, 10:44 AM

Quote:

Originally Posted by mbzman

I have a uneven idle that I've been trying to figure out. You can hear and feel the engine surge while idling. I did install a new set of Bosch HR9DC plugs and Beru wires last year to no effect. Can resistor plugs make that much of a difference?

the uneven idle is most likely due to a dirty/clogged Idle control Valve . clean out the ICV and it run evenly.
mak

ps2cho · #12 09-18-2010, 10:53 AM

I have a slight surging idle on my 300TE...I believe the only ignition part I have not swapped out yet is the potentiometer. You may want to look into this.

mbzman · #13 09-19-2010, 01:07 AM

Quote:

Originally Posted by mak

the uneven idle is most likely due to a dirty/clogged Idle control Valve . clean out the ICV and it run evenly.
mak

Cleaned that awhile ago. Was quite clean when it was removed and the valve operated freely. Didn't make a difference.

mbzman · #14 09-19-2010, 01:09 AM

Quote:

Originally Posted by ps2cho

I have a slight surging idle on my 300TE...I believe the only ignition part I have not swapped out yet is the potentiometer. You may want to look into this.

Don't you have to replace the entire fuel distributor? How do I go about checking it out?

ps2cho · #15 09-19-2010, 01:24 PM

Quote:

Originally Posted by mbzman

Don't you have to replace the entire fuel distributor? How do I go about checking it out?

You can read voltage across the terminals to test it. It is a replaceable part, but you cannot purchase it new alone. You must purchase the entire FD/Airblow block. It is a junkyard swap in reality.