Bent Spark Plug Electrode

[bigsteveokay]

Took 86 DX into Honda dealer to see why reduced power and keeps dying in neutral. They tell me two spark plugs are damaged and cylinder walls are scarred. Sure enough, I pulled it out of their lot to a parking lot nearby and plug 4's ground (side) electrode is bent almost to (or perhaps all the way touching- I didn't look closely enough) the center electrode. Plug 3's ceramic coating around the center electrode was busted all up and it was off to one side. Plugs one and two looked fine. Bent the center and side electrodes away from each other on 3 and 4 to drive it home. It drove poorly.

Replaced all four with brand new NGKs. Drove around the block, still died at idle, still had reduced power, like when I took it in. Revved high, no problem. When at high RPM up a hill all of the sudden it sounded bad and had noticeable lack of power.

Pulled all four plugs. Plug 4's electrode was fine, plug 3 was bent all the way to touching the center electrode. Ceramic on #3 also looked kinda dirty. Two and one are fine.


???? Ideas?


Pushed 3's side electrode over to the side so it wouldn't get pushed back down again but tried to maintain somewhat normal gap and replaced all four plugs. Drove again, still low on power, but at least all four seem to be firing...

[-DWM-]

Physical damage to spark plug! Something is definitely broken, I'd do a compression check. I'd put money on those 2 cyls being way down. I'd pull the head, and I'd put money on a small amount of carnage. You may have to rebuil4 or replace your engine and/or head, depends how bad it is.

[A20A1]

Too much play in the bearings?

Piston Rings Damaged?

Debris is stuck in you combustion chamber... possibly a loose screw or something that got sucked in?

Maybe you have a massive amount of Carbon Buildup on the piston... errr

[Oldblueaccord]

Check your using the correct spark plug. It sounds like the plug is hitting the piston. if the lengths wrong then they can hit the pistons. If your timing belt is slipped a tooth or installed incorrectly this could be the cause also.

Do you know if you have the A20 motor or the a18?


wp

[lostforawhile]

Check your using the correct spark plug. It sounds like the plug is hitting the piston. if the lengths wrong then they can hit the pistons. If your timing belt is slipped a tooth or installed incorrectly this could be the cause also.

Do you know if you have the A20 motor or the a18?


wp

um timing belt won't matter unless the rods got longer suddenly, the plug is fixed in one position, sounds like stuff flying around in there, probably best to remove the head ,sounds really bad.

[bigsteveokay]

i don't know which motor, no. i don't think it's a wrong spark plug issue, since only 3 and 4 have had problems.

yeah i'm REALLY hoping it's just carbon!

good idea on the compression test.