Plugs differant colours

[Micra 110]

Our 1.2 K10 Micra has a Idling problem. Just seems to die from start-up. I took the sparkys out and found....

Spark plug colours are....
1. Brown
2. Has petrol on it
3. Black and oily
4. Black carbon

The car went to the garage about 3 or 4 months ago for a service.

Have fitted New plugs, leads and distributer with new rotor arm and have replaced air filter. Apart from that everything else is fine.

Any mechanical thoughts would be greatly appreciated.

Cheers
Micra 110

 

[paul_k10_Lx]

did they use crappy chapion plugs?

 

[Micra 110]

More than likely. Can't look at the mo, missus has got the car. What with all the soleinoids on the carb, if i took them off and cleaned them up would there be any differance in running? It's an electronic ignition so no points to worry about. Any stories on diaphragm rubbers splitting? There's 56 thou on the clock.

 

[paul_k10_Lx]

its a standard 1.2 or a ecc model?

try turning the heaters up to full and starting see if it revs a bit higher

 

[Andrew]

1. Brown
2. Has petrol on it
3. Black and oily
4. Black carbon

It's rare to get so many different conditions in one engine...
1. Light brown normally means it's running ok.
2. Petrol (are you sure it is petrol and not water?) means that cylinder may not be firing at all, especially if otherwise the plug seems clean.
3. Black and wet normally means that the mixture is rich and it is misfiring (wetness due to fuel, carbon from rich mixture when it does fire). If it is oil, and not fuel, then oil is getting in there either through headgasket, valve guides, or rings.
4. Dry black carbon normally means mixture is very rich.

That's just a vague idea, plugs can mean a lot of things. It's normally best to take it for a hard drive then stop the engine quickly, and get the plugs out.

 

[paul_k10_Lx]

if there all acting differently which is strange so many probs at once might be worth gettin the head off and havin a look at what is goin on

 

[Speedle]

id replace the plugs first lol and make sure the HT leads are ok in case ones bugger and stopping the pot firing

 

[Micra 110]

Hi, i think it's an ECC model. K reg 93. I've cleaned all the plugs and adjusted the tickover and seems fine at the minute. I'm keeping my head on for the time being...I'll keep an eye on the sparkys to see what happens. Thanks for the replies peeps.

 

[Slim]

whatever you do, DON'T TAKE THE HEAD OFF.

Get yourself a nice set of NGK plugs (made in japan, not france) adn check your timing is set accuratly. Put a nice dose of redex in the tank and go for a bit of a thrash.

That normally cures most problems.

Andrew - you couldnt be more right about the plugs, however, black and oily is a comon trait of a knackered MA engine. I had this on my first MA10, and every couple of weeks, it packed up all together,