Advice. Our 87 XJ6 with the 4.2L and 81,000 miles has a very small studder/miss. We are going to do a spark plug and wire change.
What brand do you recommend?
Do you recommend changing anything else?
Do you happen to know the gap space. Told it was 35 but Im not sure.

Thank you in advance.

 

I would go to NAPA for quality and get the sparkplug wire set for your JAG,
and RNL Champion set them to .035 to .040.

Change the COIL
Change the distributor cap
Change the rotor
Set the timing

All this to start with
Walter

 

there should be a label under the hood telling you what the spark plug gap should be.

A good item to replace is the air filter for a K & N filter. You never have to replace it again.
and you also gain a little more performance on takeoff.

I do not see the reason to replace the Coil unless it is proven to be bad. Maybe a new ignition cap and rotor if yours are worn out. Maybe the spark plug wires if they are obviously deteriorated, and if you do replace the spark plug wires, do one wire at a time, otherwise you will go crazy trying to figure where they go.

 

Caveat:


Tossing parts at a car is fraught with peril.


More so nowadays ! One might replace good OEM with poor after market stuff.


Carl