I've not used my car much for a few weeks, only really to move it in and out of the garage. It's been running a bit lumpy and yesterday morning when I actually intended to use it to go to work it insisted on running on about 3 1/2 cylinders and coughing petrol out the exhaust. So once again I went to work in the Xantia ...

 

Anyway, last night as a quick test I put on my series II PTU - no difference. So then I swapped the spark plugs from the HKS Iridium to a brand new set of NGK PFR6B-11C's. The originals that came in the car from Japan were PFR6B-11 and are noticably shorter - the same as the HKS ones in fact. Anyway, immediately started first time, ran beautifully and is now sooooo smooooth. Guess the lesson is that HKS Iridiums don't last forever, think these ones had been in for about 30,000 miles, look fine, run shite !

:cool:

Andy, have noticed that even when fitting brand new iriduim plugs the tickover can be little less than normal or even uneven sometimes, I spoke to the Denso rep at the Auto Sport show earlier this year, he pointed out that on trade leaflets it actually mentions this as if it ok?

 

Jeff TT

i spoke to NGK technical & they advised not to use Iridiums in my car.

 

stick to plats IMO

Jeff,

I suspect that it's more down to old age of the Iridiums, they have been there for quite a while. Also, the longer nose of the 'standard' plugs should help provide a more even flame path and resist fouling under adverse conditions.

These plugs are supposed to last 60k right or is this just quoted for "new" 300zx's (i.e. 60k miles from a brand new engine)

These plugs are supposed to last 60k right or is this just quoted for "new" 300zx's (i.e. 60k miles from a brand new engine)

 

Stu,IMHO they wont last 60k running 1 bar.probably half that;)

Yeah thought as much.

Thanks