I've decided that while I have my injectors and hoses out (Probably this week) I'm going to change my spark plugs, wires, and rotor. I've heard stories of issues with misfires etc. from XJS owners who've switched from the plugs specified in their owners manuals. Mine says to use Champion plugs, but I'm more inclined to use the NGK 2238s, as I've heard good things about NGK and they seem to be the other go-to brand for XJS owners. In all other cars I've owned I've used (and Loved) e3 plugs, I imagine those won't work well in an XJS though if the systems so finicky. Basically, my question is, in an '83 5.3L can I get away with using NGK plugs even though the manual says Champion? I'd really like to only have to buy one set of plugs. Also, have any forum members tried e3 plugs in their XJS'?
Thank you all so much for how much you've helped me already.

 

In later years Jaguar specified NGK in the V12s.

I used NGK in mine ('88 XJS V12) with no problems

Cheers
DD

 

For me, Champions always seemed to foul so I don't use them.

NGK's and Autolite's always worked well so those are the brands I prefer.

Mark

 

I ONLY use NGK.

Agreed, the handbook states Champion for plugs ,Castrol for oil, etc, etc, and this is due to those manufacturers being the OE supplier at the time, simple as that.

Things change, but who gets a handbook update from any manufacturer??????. NOT me.

On the HE I use BP6EF, and have done so for a very long time.

A lot of misfire issues, not all, I have experienced is that the porcelain of the plug is cracked during installation, especially 1A, 1B, 5A, 6B., and shows up as a misfire sometime down the track.

I have never used KLG, Champion, Bosch in any Jag.

 

Do you by any chance know what NGK plug you used?

 

I would recommend the "V-Power" plug Part #TR5. Gap them to .025".

Mark

 

My 89's manual says BR7EFS, will those BP6EF work? and any suggestions from the great wisdom resident on here for leads?

 

Yep.

I run Magnecor ONLY on any Jag that still runs leads.

 

I've used NGK ever since I was a kid racing 2-stroke Motocross bikes, and, I've used them for 15 years in my XJSs. Excellent plugs.
Champion has a good reputation, and, I'm sure you'll find plenty of people who will swear by them, but, for me, they just don't seem to work as well, or, last as long as NGKs.
A few months ago, I got curious about E3 plugs, so I went to their website to research them, and to see if they have something for the XJS. I couldn't find anything in their online catalog for the V12, so I contacted them via their contact email. Within 24 hours I got a reply saying that they don't make a plug for the V12, nor, did they give any indication that they have any interest in developing one for it.

 

i use NGK Iridium, seems to start quicker, idle smoother!

 

Grant do you use the 8mm magnecor or the KV85? and any particular reason for the BP6EF over the BR7EFS?

 

Standard 8mm from memory. They have been in there since 1994, and I really dont look.

BR7EFS is very old NGK spec.

They introduced the "split V centre electrode" way back, down here, and on that particular plug simply dropping the "S" gets the V as versus the standard flat face electrode, hence the "S" for Standard.

The heat range is just me. I prefer 6's here with our fuels and that engine. The 7's are just a tad too hot.

Then I got scientific, HAHAHAHA, not in your wildest dreams am I scientific. The "P" is for projected nose, simple. The no P is a flat nose plug and fraught with fouling issues. The P puts the spark IN the combustion swirl, and also out in the open as compared to the flat nose plugs. Take a look, it is not rocket science. AND NO, the plug will NOT hit the piston, it just cannot happen on a HE.

The R is for Resistor, and I see no need for resistors on this ignition system, but that will evoke a War and Peace thread that I will NOT participate in. I have run non-R plugs for as long as I can remember, but the X300 and the S Types are very different and run R plugs.

I get around 40K kms from plugs in the HE.

 

Thanks Grant, from this humble novice. I am constantly amazed at the wisdom you freely dispense on here very much appreciated

 

Grant sorry to pester you with questions but when you say BP6EF and split electrode, thats means the BP6EF-VGA (NGK 6194) as opposed to the BP6EF (NGK 4666)?

 

Grant, I was made to understand that the numbers for NGKs run backwards in terms of how hot a plug is. The BRK6E is not as hot as the BRK5E.

The 7s would be a tad too cool, no?

 

I run the 4666 short number. This the "V" groove centre electrode style plug.

I have never seen the need for fancy style plugs in such an old spec engine, again, my opinion, and no other reason than that.

The NGK rep down here gave me 12 Platinum plugs to try, way back, and I noticed no real benefit in any area, and the cost (if I had to pay for them) simply could not be justified. Maybe they have reduced in price, never looked.

 

You are SPOT ON, I got that wrong.

 

FWIW, I have run NGK BR7EFS with no problems. Right now I run Unipart copper core plugs as I bought about 80 for 5 quid on ebay and they are fine.


Greg