Spark plugs and gap.

[Coryz760]

I got a 5.9l ... Never done the tune up myself. My spark plugs all gap just after .040. if it's not exactly that will I run into problems?

 

[Coryz760]

I got a 5.9l ... Never done the tune up myself. My spark plugs all gap just after .040. if it's not exactly that will I run into problems?

 

[JustinH]

Honestly I didn't gap mine and have no problems related to that. Other issues yes. Make sure they are copper core though. Is a platinum and you will have issues. Our ignition system isn't hot enough to make good spark with them. Learned that on the hard way and had to redo it.

 

[Yeret]

I've always run .040" gap and never had problems. As Justin said, make sure to use plain ole copper plugs as there are MANY stories of people running platinum or (heaven forbid) iridium plugs with our factory coils and having running problems. And if you're thinking of averting that problem by running a hotter aftermarket coil, there are also stories of people barbecuing their ECUs after using them (something to do with "voltage backfeed" or something. If Pepper pops in, he could elaborate).

I've got a new set of NGK plugs to pop in sometime this season and am actually thinking of leaving them at .035" just to see what (if anything) happens.

 

[Mop]

I've been using NGK .035 in my '99 for many years, and it's always run fine.

 

[JustinH]

I was also curious of the E3 spark plugs. But don't think they have a copper core version.