Page 1 of 1

Misfire

Posted: Tue Oct 06, 2009 10:35 am
by Kevin
I have been following the site with interest, joining yesterday with Simon's help. Thank you Simon.

Have a 1999 3500 LWB Facelift with 166000km that has a recurring misfire/jerkiness around 2000rpm.
Spent almost R10k on TPS switch, plugs (one platinum tipped was arcing after 28000km), coil, injectors ultrasonic cleaned and one replaced, and electrode cleaning and sealing of plugs/leads/coils.
The costly process eventually eliminated the symptom for 10000km, but it appears to be back again.
Otherwise utterley reliable and good service for 80000km over five years, used mainly for weekends and long distance trips. Really a pleasure to travel in.
Any ideas before I throw more money at this thing!!!

Re: Misfire

Posted: Tue Oct 06, 2009 9:23 pm
by HBannink
Kevin wrote:Any ideas before I throw more money at this thing!!!
This "thing" is a highly specialized and sought after example of the finest automotive engineering, it is a Pajero :twisted:

On a serious note, check your ht leads as I have come across a few with intermittent breaks in the carbon inner of the lead where it would just have enough resistance at a certain harmonic vibration to cause a miss. If not that I would go for plugs as the 6g7 engines are quite finicky in that regard.

Henk

Re: Misfire

Posted: Wed Oct 07, 2009 1:43 pm
by Kevin
Thanks Henk.
What plugs are best for this car?

Kevin

Re: Misfire

Posted: Wed Oct 07, 2009 11:06 pm
by HBannink
I prefer to use the standard ngk plugs and change them on a regular basis. I know it is a bit of a schlep to do on the 3.5 but it makes me feel better knowing that the plugs are "fresh". VERY IMPORTANT make sure the plugs are the correct spec as mitsu uses a resistor plug and if you change this to a normal one you are in for endless drama and rough idling.

Re: Misfire

Posted: Thu Oct 08, 2009 2:46 pm
by Kevin
My garageman has confirmed the fitment of NGK BKR5E-11 plugs. Could these be failing after only 10000km?
Not easy to check of course on a 3.5 without incurring labour cost.

Re: Misfire

Posted: Thu Oct 08, 2009 9:38 pm
by HBannink
I have had plugs fail after 5k so it is quite possible. there could be an underlying cause as well like a valve stem seal leaking and contaminating it. For the same price it could be the plug lead and unfortunately you will have to test to pinpoint the cause. The plugs that you have quoted seems to be the correct ones as the R indicates that it is a resistor plug. (see attachment)