Dual electrode plugs?

I'm about to change the plugs, when I noticed in the owner's manual and online that I'm supposed to use dual electrode plugs for this engine.

The parts place across the street sold me NGK BKR5EGP plugs, which have only the one electrode.

What's the deal? Are the plugs I have ok to use, or is there really some benefit to dual electrode plugs?

 

Take them back & get the dual Denso's (or its equivlent) 3.4's need the dual electrode..

 

Designed for dual electrodes. Use dual. Have had customers use wrong plugs and developed idle, drivability, mileage issues.
Why would you not use what it tells you too. Can't figure out why they would give you those.. Glad you noticed..

 

Im wondering if this is the problem with ym truck I switch to Denso IK20s like the TRD 7th injector calls for but they are a single electrode plug.

 

Can't really comment on the whole 7th injector thing but pretty sure Toyota matched the dbl electrodes for the hemispherical (Hemi) design, I mean its not written in stone that you can't run singles but if you do you could probably expect some not-so-nice anomalies to go with it , rough idle/possibly some stalling, poor gas mileage/diminished performance, etc:

 

I had poor low rpm performance is kicking, bogging. Switched back to the duel and it went away.

 

I rest my case....

 

I need some help, please.

I changed the plugs using the single electrode that I had. At the same time I changed the plug wires.

After that it started very hard and idled rough. It seemed to run ok once I gt it started, but sometimes had to try two or three times to get it started.

Went back to the parts store with the double electrode plugs that I took out of it and bought six of those. With those in it starts hard and runs rough.

Put the original plug wires back on while leaving the double electrode plugs in. Still starts hard and runs rough.

Did a coil die on me? I can't hear a vacuum leak.

Please help. Frustration is high.

Thanks,

Matt

 

No. I checked that. I've put the new wires, the old ones back on, and the new ones again. All with the same results.

It ran fine before I messed with it. That'll teach me to do maintenance.

 

Never had issues running single electrodes on mine n/a, trd sc, or turbo 400whp+. ????? I would also like to add I have been around and tuned many 5vz's running single electrodes of correct heat range and gap without issue.

 

Matt
Weesa is right. You need the right stuff.
Double check what you got.
It's possible you could have done something to a coil but the check engine light should come on for a skip almost right away.
Most times you can't hear a vacuume leak. Try a spray bottle of water and squirt around the intake hoses and lines. Intake manifold. Maybe you cracked a vac line.
If that is all you did was yank the plugs and wires you must have done something you don't realize.

Real hard to diag over the net. We can only give u things to double check.

 

The Tacoma 5VZ-FE uses dual-electrode plugs because it has 3 coils for 6 plugs. This configuration is called a 'waste-spark' system.

Each coil fires two spark plugs at once. The two plugs are in opposing cylinders in the firing order, both at TDC at the same time. At TDC, one cylinder will be at the top of its compression stroke, the other at the top of its exhaust stroke. So when the coil discharges, one plug fires in a compression stroke (ignition), the other fires in an exhaust stroke (wasted).

Since each plug fires twice as often as necessary, that speeds up the wear and will prematurely widen the spark gap. Also, the two plugs on the same coil fire at the same time but with opposite polarities. Older and/or cheaper single-electrode plugs aren't designed to fire with reverse polarity so that also contributes to premature wear.

Dual-electrode plugs will last longer since as the gap widens on one electrode, the spark will move to the other electrode.

However, newer technology single-electrode plugs, like iridiums or dual-platinums, can last just as long or longer than older dual-electrode plugs. Dual-platinum doesn't (necessarily) mean dual-electrode, it means the center electrode and the ground electrode are both platinum, as opposed to just the center electrode being platinum.

OP, the NGK BKR5EGP plugs that you got are ok, they're NGK's G-Power platinum plug, but they aren't dual-platinum. Only the center electrode is platinum so they'll wear out faster than a dual-platinum (or an iridium or a dual-electrode).

To read about them, go to this page and search for your truck:
http://ngksparkplugs.com/part_finder/car_truck_suv/default.asp

Denso IK20 are iridium plugs. They're fine (and very good plugs). IK20 is one heat range colder than stock. TRD specified that to help reduce pinging from the supercharger. The URD 7th injector kit uses Denso IK22, which is the same plug but one heat range colder than yours and two heat ranges colder than stock. If the problem you're experiencing is pinging, then switching to IK22s will help. If your problem is fouling, then you'll need to go back to stock heat range but that will likely cause pinging from the supercharger's hot compressed air. (If you don't have a supercharger then definitely go back to stock heat range).

The 5VZ-FE does have hemispherical (pent-roof) heads, but that's not the reason for dual-electrode plugs.

 

Ok, I guess I'm missing the point, maybe your blown/aspirated hot rod is now innocules to dual electrodes Toyota recommends, you really should call them & tell them to re define their recommendations

 

Then it must be for emissions/combustion , can't really see any other reason for doing so, that "waste" thing on the exhaust stroke must be last ditch effort to burn off any left over un burnt fuel

 

No, it's for cost. It allows them to use only 3 coils instead of 6.

 

bbob is explaining this well. Oh and in this situation only iridiums were used and gap tightened to ensure plug life and everything running good. The iridiums did not wear like I expected them to either.

 

I can't hear a vacuum leak (and I tried), but it has been indicated that I likely won't be able to hear it anyway.

The plugs that are in it now are new

$6 NGK BKR5EKB-11 NGK Spark Plug Stock # 3967

NGK BKR5EKB-11, as were the old ones that I took out of it. The old ones were used up - the center electrode had eroded to the point that it looked like a cone and the gap was huge.

My sample size is small, but I've driven a little this afternoon. I feel like it may be starting better, and runs well when the rpm's are above idle. The idle, however, is quite low. 500 and stuttering around even lower at times.

Does those clues yield any other suggestions?

Thanks for the help.

 

I'm not so sure of your analogy, & why the fuck would each plug require its own coil anyway, i don't see any cost cutting measures really... Not sayin' you're wrong but I will say that every vehicle I've owned with dual spark/plugs was done for nothing more than emissions & keeping EPA happy