Not using Dual Ground Electrode Plug on Avalon

[Param]

Last spring I replaced (1st time) sparkplug on 99 Avalon (with 150,000 miles) with single ground electrode NGK Platinum. Original plug had two ground electrode (Denso PK20TR11).

Just by accident, I decided to read the owners manual, & found that Toyota specifically asked owners to avoid single ground plugs. It states that using a single ground plug would affect performacce of the vehicle ,etc., etc..

What is the effect of not using dual ground?

Although I never had a starting problem, I decided to change the plugs (after 150,000 miles), because I intent to keep this for at least another 6 yrs.

However, after spark plug replacement, out of the blue car refuse to start in # of instances. Usually, I remove the key, wait 30 seconds or more & start it again successfully. There is no other warning. This happened to me a hand ful of times with in a month after plug change. I never had this problem beore. Later on this happened to me few times.

Mechanic said that over time starter motor connectors go bad & that could cause this spontaneous starting problem. However, since this is not a totally dead situation, I am leaving it as is.

What type of plugs you replaced with during tune-up?

[blkavalon]

i use NGK two tip plugs they have a better spark. but using one tip plugs wont hurt or reduce performance significantly at all. so many toyotas recommends two tip plugs and i see many people use single tip plugs and no problems at all.

i dont think its your plugs at all. so when you try to start does the engine turn at all? if it turns good then its not the starter.

[csaxon]

I wonder why they put this on the engine?

[Bitter]

has to do with how the combustion chamber is designed or something, a single ground shrouds the spark or something. we always use double ground when called for, platinum when called for, etc.

[blkavalon]

Originally Posted by csaxon

I wonder why they put this on the engine?

i know what you are saying, toyota recomends only two tip plugs. but using single tip cant cause non-starting issues. i work in a parts store there are many people want the cheep plugs like single tip autolite non-platinum plugs. so far no complains. even though i don't recommend it.

[artbuc]

Originally Posted by blkavalon

i use NGK two tip plugs they have a better spark. but using one tip plugs wont hurt or reduce performance significantly at all. so many toyotas recommends two tip plugs and i see many people use single tip plugs and no problems at all.

i dont think its your plugs at all. so when you try to start does the engine turn at all? if it turns good then its not the starter.

I thought the reason for double-tip was that the plugs fire on every stroke because a each pair of cylinders share one ignition coil.

[silkydraws]

It's because of shrouding. both ends get spark each time they fire.