new plug leads & plugs for M117 - resistor plugs/leads? HELP

[mccrackenj]

I want to treat the C126 to a new set of leads and plugs, but I'm unsure re resistor Vs non resistor plugs and resistance in the leads.

From what I've read the original leads would have had significant resistance built in, so were supposed to be used with non-resistor type plugs.

My questions is - if I replace the leads with new, will they not have this same level of resistance and should I therefore use resistor type plugs, which most modern plugs are?

thanks all

[nav p]

I have just replaced my leads,cap and plugs on my 1991 500SE

I got plugs from Mercedes,got my leads(Beru) and cap(bosch) from KMS and the car is running fantastic

Be aware that the leads are differant for the 265bhp engine...

[mccrackenj]

Thanks for replying - but were the plugs the resistor type or non-resistor?

Where the leads just 'normal'?

[nav p]

normal...

car seems to run better if anything

[mccrackenj]

Thanks.

I think I'll go for ordinary leads.

And the plugs - do you remember if resistor (i.e. will have an R in the model no.) or not?

[SamPet]

Hello. I'm a w126 geek

The best plugs for the UK are copper core non-resistor plug (as per OE spec)

Bosch W7 DC can be bought as new-old stock (eBay) or picked up from some motor factors. Avoid Bosch plugs with "R" in the code - denotes aforementioned resistor type

Recommend

http://www.ebay.co.uk/itm/like/161354583669?limghl...

[mccrackenj]

SamPet said:

Hello. I'm a w126 geek

The best plugs for the UK are copper core non-resistor plug (as per OE spec)

Bosch W7 DC can be bought as new-old stock (eBay) or picked up from some motor factors. Avoid Bosch plugs with "R" in the code - denotes aforementioned resistor type

Recommend

http://www.ebay.co.uk/itm/like/161354583669?limghl...

Thanks SamPet

Would you recommend non-resistor plugs even though I will be buying ordinary leads without resistors 'built in'?

I the end I have bought 2 sets of plugs, one with resistors (Bosch) and one without (NGK BP6EFS) - so now I don't know which to fit

[SamPet]

Hmm. If you're using non OE leads you might need the resistor plugs. Someone with more knowledge would need to confirm. If you have the time you could try fitting both sets to see which gives a smoother idle/ delivery?

[mccrackenj]

SamPet said:

Hmm. If you're using non OE leads you might need the resistor plugs. Someone with more knowledge would need to confirm. If you have the time you could try fitting both sets to see which gives a smoother idle/ delivery?

That was my initial 'logic' which is why I bought ordinary resistor plugs - then I got worried because of the amount of threads on various forums saying 'non-resistor or nothing!' but most of those threads assumed MB original spec leads I bet.

I think I'll fit the non-resistor type first and see how it runs.

Thanks

John McC


ETA: wish I'd clicked on your link before now - crivvens, that's V cheap!!

Edited by mccrackenj on Sunday 13th July 20:51

[mccrackenj]

any other opinions?

PS - just got a set of leads delivered from well known national parts supplier - all 5 of them, 1 coil lead and 4 short plug leads. Marvellous.

[r129sl]

Years ago I fitted Beru leads to mine and was very happy with them. I cannot for the life of me recall what plugs I fitted. I do recall I had to take the little caps off the end of them. I'll ask my man what he uses when I see him next week. He knows everything about this vintage.

[mccrackenj]

r129sl said:

Years ago I fitted Beru leads to mine and was very happy with them. I cannot for the life of me recall what plugs I fitted. I do recall I had to take the little caps off the end of them. I'll ask my man what he uses when I see him next week. He knows everything about this vintage.

That would be brilliant, thanks. As above, I now have a set of resistor and non-resistor but would like to fit the right type 1st time.

cheers