Bosch Platinim +4 after 101k miles

[1maniac]

quote:

---

what's "reverse firing"?

---

Its a term used when referring to DIS ignition systems. Half the plugs get fired in reverse. This is why you want a double platinum plug that has platinum on the side AND the center electrode. If you use regular platinum plugs that only have a platinum on the center electrode then half the plugs will wear out faster.

 

[blupupher]

quote:

---

Originally posted by kenw: what's "reverse firing"?

---

also know as a waste spark or dump spark. Newer Jeeps have this same feature, and same problem with single tip platinum plugs. A little more explanation is that you have 1 coil for 2 plugs, and the coil fires both plugs at the same time, one on compression cycle and ignights the fuel, one on exhaust (so no fuel to burn in cylinder)

 

[Elroy the Unique]

Which car makes typically use waste firing? Does GM on its V6s?

 

[tom slick]

any engine that has one coil for 2 spark plugs uses "waste spark". gm uses it alot, my mazda has it, many motorcycle engines...

 

[cryptokid]

i think most of the mazda 4's have or had it.

 

[Steve S]

quote:

---

Originally posted by Whimsey: How does the spark know which electrode to go to? . Whimsey

---

The electrode with the least resistance will fire first,Im sure the resistance will change during firing.

 

[kenw]

since the camry these plugs came from (3.0L v6, 1997) has 1 coil servicing 2 plugs, I would guess that makes it "waste spark" by Tom's and blupupher's definitions. The coil packs are mounted on the front bank and the secondary plug wire feeds the 3 backside plugs. thanx for the help.

 

[G-MAN]

quote:

---

Originally posted by 1maniac:

quote:

---

what's "reverse firing"?

---

Its a term used when referring to DIS ignition systems. Half the plugs get fired in reverse. This is why you want a double platinum plug that has platinum on the side AND the center electrode. If you use regular platinum plugs that only have a platinum on the center electrode then half the plugs will wear out faster.

---

 

[jason07-1zzfe]

What's so funny? That's essentially how it works.

 

[G-MAN]

quote:

---

Originally posted by blupupher:

quote:

---

Originally posted by kenw: what's "reverse firing"?

---

A little more explanation is that you have 1 coil for 2 plugs, and the coil fires both plugs at the same time, one on compression cycle and ignights the fuel, one on exhaust (so no fuel to burn in cylinder)

---

No, the above explanation is "how it works." The "explanation" I was laughing at makes no sense.