Thread: 2,25 Spark Plug Choice

Originally Posted by CapeLandy

Hi Gents

Anyone know how critical is the choice in using different spark plugs.
The reason I ask is the following: When I first bought my Series III many years ago I got a set of plugs from a motor spares dealer who didn't ask whether it was low or high compression head on the 2,25 petrol. I never used them because I noted a different type when removing the old.

I have just found one current plug NGK BP6ES with a weak spark and the engine is therefore spluttering.
I fitted one of the original plugs which I never used Champion N9YC and she sounds fine again.
Instead of wasting the Champion plugs, I was wondering If I can use them.
This would hapen on the day that I was supposed to take the old girl to a dealer to see how much I can get for her. I am trying still to raise enough funds for the 08 Fender but am still horibly short. Thought I would get a better price on the VW but alas - dealer is screwing me.
Cheers 4 now
James

H/C 8:1 Champion N12Y
L/C 7:1 Champion N8
Regards Frank.

plugs break down over time so I reccomend that where possable you buy your plugs in those plastic blister packs as opposed to individual cardbord boxes.

while you can intermix compatable plugs (the 2 that you specify ring bells in my head that say they are compatable plugs) as a general practice you dont. And to that effect some engines like one brand more than others and yes that means you can have 2 engines the same sitting side by side and they will stutter about on one type of plug but not another and it'll be a different breed plug for each of the engines..

IVe also found that stepping up or down a level in the temperature range of the plug can make a big difference, mainly on carbied engines and not so much on injected donks.

I was not planning on just changing one only. I wanted to use all four of the N9YC as oposed to the ones for my low compression head.
Thanks for reply - just wanted to know if any damage could be caused using other plugs.
James

Originally Posted by CapeLandy

I was not planning on just changing one only. I wanted to use all four of the N9YC as oposed to the ones for my low compression head.
Thanks for reply - just wanted to know if any damage could be caused using other plugs.
James

Unlikely to cause any damage, but a lower temperature plug than the correct one will tend to foul and hence misfire, whereas a hotter than desirable one will overheat and may damage the plug or cause running on or possibly detonation, and the overheated plug is likely to break down and cause misfiring. How critical the choice is will be dependent on how the vehicle is driven and in what conditions.

John

just need to drive to the dealer and back and see if he gives me a good price for her. If not ...no more 08 Fender

Fitted new plugs and started engine - all seemed ok on idle.

Took off to drive to dealer and vehicle started jerking all over again but fine on idle.

Could the lead to this spark have intermittant fault or could the dizzy cap have a fault?
Only seems to be on one cylinder.
Can a faulty lead bugger up a spark plug. The new plug took away the misfire on idle but on load it jerks. I have no spare leads to test so I had better get a set so I can be sure all is ok and keep the rest as spares for possible new owner.

Thanks
James

Originally Posted by CapeLandy

Fitted new plugs and started engine - all seemed ok on idle.

Took off to drive to dealer and vehicle started jerking all over again but fine on idle.

Could the lead to this spark have intermittant fault or could the dizzy cap have a fault?
Only seems to be on one cylinder.
Can a faulty lead bugger up a spark plug. The new plug took away the misfire on idle but on load it jerks. I have no spare leads to test so I had better get a set so I can be sure all is ok and keep the rest as spares for possible new owner.

Thanks
James

For what it is worth, last time I had that problem it WAS the lead! But I didn't find it until that plug stopped firing at all.

John

could be a bit of both, pull the dizzy cap off and check it for signs of tracking, arc outs and that the little contacts under each plug socket are clean and secure in the housing.