Re: E30 M3 Plug Leads

[Aaron Lung <alung@xxxxxxxxx>]

Abbs,

Rather than replacing one a a time, you might as well replace
all of them at that same time since they're all basically
subject to the same conditions.  If you can manage to get them under
warranty, it'll save you a bunch.

My maintenance docs don't mention anything about replacement
other than 'inspection'. 

My E28 was randomly misfiring as a muffled puff every few seconds
at idle, and it was creeping up closer towards the HC emissions limits 
each successive smog check.  Swapping out the distributor cap, 
rotor, and plugs didn't make any difference (I've never paid so
much for a stupid cap and rotor--OUCH!!). 

My original wires looked perfectly fine when 'inspected', and 
they measured well within specs.  The emissions droids were 
suggesting my Cat was messed up. [not!]  I gave up and replaced 
the $parkplug wire$ as a last resort.

That fixed my idling, and my emissions also measured at the
normal low at the next emissions test.

aaron
88 E28, 79K


> 
> My 1990 M3 has been misfiring regularly and was diagnosed as having faulty
> plug leads. The king lead and lead 3 were replaced under warranty and solved
> the problem.
> 
> More recently the same problem has occured and lead 1 is suspected.
> 
> Is there a documented lifetime or scheduled replacement time for leads. They
> are very expensive to replace.

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