Thread: Misfire on my 240. Halfway diagnosed. Please give advice.

So I have a misfire on the #2 cylinder. The plugs looked like total ****, so I replaced all of them, gapped them to .044.

Misfire is still there. No CEL. Also, it seems to go away when I keep the motor steady above 1700rpm or so.

Where do I start?

PS, I don't know if this is related, but my car burns a significant amount of oil...probably a quart a month if not more.

?

Train of though is like this:

Cylinder 2 is misfiring. Plugs are black?
Spark is weak or there is too much fuel
Is the injector bad?
You replaced the spark plug, and problem repeats.
Plug wire bad?
Cap+Rotor worn?

Are all other cylinders looking okay?

What's the engine?

this.

give more details. have you checked/cleaned/replaced any of the injectors. have you checked for spark? and when my ka was missing, i replaced the plugs, checked spark, and cleaned the injectors and it was still missing. i figured it could only be intake, and that one of the valves was floated. i drove it back(about a 2 hour drive) on 3 cyls and when i shut the engine down after driving, let it chill for about 30 mins, then left where i was... my ka was back to life! it was a miracle.. idk what that says, but if must have been a magical ka..

GOOD LUCK!

Yeah, when KA's realize they are not in a truck they throw a tantrum.

Here are some pics of the spark plug. Camera isn't great, but it's the best I can do. The very top of the spark plug looks like white oxidization or something. The inner part of the electrode is black and worn down.

Looks like a healthy plug, but I can't tell because its blurry You want a healthy brown. Not white or Black.

Ya the top is white, inner part is black. Doesn't look healthy to me.

How do I check for spark? Just the pull the plug wire off while it's running and look at the end of it?

Fuel injectors haven't been messed with at all since I've owned it. I doubt that they have ever been serviced. Car has 173,000 on it.

You can invest in a timing light. You can also do as you said... be sure to place the plugs on the intake manifold. Also pull the injector.

I have a cheap timing light. I'll take a look.

So for the #2 cylinder, I actually pull the new spark plug back out, keep it attached to the plug wire, unplug the #2 cylinder injector, and then just run the engine?

Never thought of doing that. Makes sense though.