Spark plug condition - Running too rich?

Calmman · Postby **Calmman** » Fri Jan 03, 2014 1:42 pm

Hi everyone

Those plugs are from 1995 CC Lancer 1.5L Carby... do you think it is running too rich?

The deposit can scrap off by screwdriver without too much effort.

Interestingly one side looks better than the other.. hmm... what do you guys think?

And when it is under load (like going uphill) it does misfire a bit... wondering if I should replace the leads too??

Thank you in advance...

davekmoore · Postby **davekmoore** » Fri Jan 03, 2014 7:38 pm

Are they the original plugs?

ja9 · Postby **ja9** » Fri Jan 03, 2014 9:56 pm

Mate, that looks more serious to me than a rich mixture. Does your car overheat? A rich mixture is either black soot or a black wet plug. Yours looks like there are deposits on the plug. Either way change the plugs sooner rather than later and look into your issue. Take the plugs to a mechanic and let them advise you.

zossy1 · Postby **zossy1** » Fri Jan 03, 2014 10:05 pm

Is it using oil?

davekmoore · Postby **davekmoore** » Fri Jan 03, 2014 10:07 pm

Not quite sure how serious the OP is?

Calmman · Postby **Calmman** » Fri Jan 03, 2014 10:23 pm

Thank you guys

The temperature is good and not using oil.. however it does misfire when I accelerate up steep hill... (So I just easy the throttle and use lower gear)

May be I should recheck the gap and fit new set of spark plug leads? Still using the original one (since 1995).

The plugs are "Champion" and it is suitable according to the guide book.

The car does ping a little bit under load but I always easy the throttle when it happens..

93_Clubman · Postby **93_Clubman** » Sat Jan 04, 2014 10:18 am

Calmman wrote:May be I should recheck the gap and fit new set of spark plug leads? Still using the original one (since 1995).

The car does ping a little bit under load...

Check ignition timing, & new plugs & plug leads won't hurt if they date from 1995.

fcruz3r · Postby **fcruz3r** » Wed Jan 08, 2014 9:51 am

Is there oil on the plug leads? Could be the valve cover gasket is no longer sealing right and leaking oil on the plugs

hks_kansei · Postby **hks_kansei** » Wed Jan 08, 2014 10:16 am

Looks oily to me, the black indicates a slightly rich mixture (but may also be oil contamination)

Replace the plugs, and leads first of all to get a clean slate to check from.
Then check the static timing (you'll need a timing light)

Also check that the vac advance is hooked up to the dissy (and intake manifold).
It may also be worth taking the cap off the dissy and checking the points and rotor look ok, also that the centrifugal advance isn't stuck.

Pingin on hills could be that the timing is too far advanced, but it could also be oil contamination in the combustion chamber which lowers octane and makes pinging more likely.

I'd say oil is getting in somewhere, you'd hope it's a gasket, but expect rings.
Doing a dry, then wet, compression test will tell you if it's rings.