Nissan: Sparkplugs???????

lee wrote: 

Check the coils?

lee wrote:
 

What brand of plugs? Bosch platinums?
--

Steve

http://www.atlantaracing.com

Ive got a standard coil ...
Auto electricians have told me that would not cause problem
Bizarre

"Sarky" <com> wrote in message
news:uyzLb.49003$videotron.net... 

Just some ideas, probably wrong but I've a lot of high voltage hostile
environment experience in military electronics (and they go wrong all the time),
so for what it's worth......
Are they resistor plugs? Measure with an ohmmeter from the connector to the
tip, should be the same as the good plugs within 20% ish. Could be going high
in resistance due to too high a voltage & current, the only causes I can think
of are a very wide gap in the distributor cap/rotor arm for that HT lead (I
don't know if an R30 has a distributor) and perhaps an open circuit HT lead
where the spark is jumping an internal gap so you don't notice anything wrong
you just get a higher voltage developed before the plug will fire. Another
cause of resistor failure is engine vibration, this would have to be worse just
on that cylinder though, so it would have to be a high frequency resonant mode
local to that part of the engine or the other plugs would suffer as well,
perhaps a worn bearing on that cylinder or just a loose bolt? A length of
tubing used as a stethoscope should be able to tell you if there's extra noises
in that cylinder area. A different brand of plug may help (I like NGK in
Japanese motors).



"lee" <net.au> wrote in message
news:hwxLb.2778$bigpond.net.au... 

anything does it

Champion, bosch , NGK
Bosch are worst maybe last a week

"Steve" <com> wrote in message
news:btnkkh$9e338$news.uni-berlin.de... 
doesnt 
dead 

I don't think it's the sparkplug. It may be a bad cable or connector. The
plug is fouling. Also check your grounding wires from the engine to the
chassis.

"lee" <net.au> wrote in message
news:hwxLb.2778$bigpond.net.au... 
etc. 

lee wrote:
 


Try the right NGK's and then when the plug "dies", swap it into another hole
instead of replacing and see what happens. Might be a clue.
--

Steve

http://www.atlantaracing.com