Spark plug / Miss fire Issue 4agze

[shazeal]

Hiyas, I replaced the spark plugs a few days ago but didnt have time to do a tune up at the same time, has been driven for a few days and has been miss firing etc.
Today I pulled out the crank angle sensor and aligned it properly, did the timing 10deg on 95 fuel. Checked compression 150+ on all cyls. Rechecked gap on all plugs (0.8mm), retorqued and re-assembled everything.
But when I pulled out the plugs before doing the comp test, 1,3 and 4 all had blackish deposits around the rim, core was white, nodes were black/brown (normal for 4 day old plugs yea?), but plug number 2 was brown as and kinda wet looking.
I checked the leads all around 3-6k resistance, but i did notice the tops of the plugs were quite badly pitted right in the middle of the top, all 4 of them.

I cant figure it out, seems like 2 is getting a spark ok, but possibly missing occasionally would that explain all the brown/wet stuff on it?

[l1ttle_d3vil]

isn't black = over fueling and white = running too lean or something?

[Rick]

Dry sooty deposits indicate a rich mixture or weak ignition, which can cause misfiring, hard starting and hesitation.
make sure the plugs have the correct heat range, it could be a problem with your fuel system? or ignition? or ecu?


when you say wet looking, wet as in oily wet or petrol wet?

[Brick]

is this my old car?
because it happened to me, but that was beginningof this year, we coudlnt work it out, so we switched plugs around and put them in different holes and it worked

[shazeal]

The plugs are BCPR6EP-8 NGK platinums. The plug that looked wet, didnt look oily, just wet, so guessing petrol.
I swapped the number 2 plug to 3 just to verify it wasnt the plug, car was warmish just above the cold mark, gave it some s**t around the block bout 5 min driving, loads of power (well as much as usual), cruised ok, idled ok, got back left it running for 5 more mins, was ok for a minute, but then started steaming out of the exhaust, and pretty bad missfire. So seems it only happens when the car is hot... Pulled out plug 2 (previously plug 3) and it wasnt wet, pulled out plug 3 (the one that was brown before) and the brown crap on it had turned light grey, which is what its supposed to be like afaik.
I just chucked the crusty old NGK iridiums that were in before back in (was running fine before I changed the plugs, but wasnt bad immediately after changing), and once the car heats up, same thing, steam + missfire.
Getting a bit tired of taking the intercooler on and off

[CAMB01]

Sounds like you have a blown head gasket.
There is water getting into the cumbustion chamber causing the plug to miss, that would be the 'wet' on the plug.
Pressure test the cooling system

[Brick]

heh it must be my old car, those plugs cost me good money

did u check where the leads connect to the coil pack? that happened heaps where when id give it shit or if it spun up it would pop out or just sit there touching. Try that? ive got the caps for them in my room if you ant them

[shazeal]

Hey, yea i think you posted before saying it was your old car. As above Ive tried putting old plugs back in, and switching order of new plugs. Ive been thinking about when it started doing it, and it wasnt until I tested the timing and tried to adjust it a few days ago, i moved it back to 10deg and it would missfire. Put it back to where it originally was 5deg and it ran better but still missfired slightly... coincidence? Im stumped
Ever since I got it it has popped and cackled a bit when taking foot off the accelerator and pops occasionally when shifting down. But never missfired when idle even after long trips round town on hot days...

[CAMB01]

Steam is not a good thing to be coming out of the exhaust.
Does the car use water?

[shazeal]

Ok engine was slightly warm to the touch this time, under the cold mark on dash, idles fine cold, no steam, not until gauge reads about 1/4 does it start to steam.
Reseated the plug leads, and advanced the timing a bit (didnt check with light just put it back so was idling around 800rpm) but guessing around 5deg again and it doesnt missfire nearly as much, still steaming tho on idle. Took it down the road, no steam out the back with foot down upto 6.5k rpm, got out and still a bit of steam comming out, it is a bit cold outside atm?
The compression tested 150+ on all 4 when i did it, double checked em all.

How do i test the water pressure? Never done that before.

[l1ttle_d3vil]

get a pressure tester, or take it somewhere who has one. its a straightforward job, just need to clip something onto the radiator cap and give it a few pumps and you should know if its leaking or not.

and im sure you would've noticed this already seeing as how many times you've taken the plugs out, but one of my spark plugs was cracked a while ago (the white part between the HT end and the hex). when cold it would run mint, but the warmer it got the more it started missing. when it was warmed up, it would miss and stutter all the way up to 4500rpm/TVIS then would go fine.

had me stumped until I pulled the spark plug out and it fell to bits in my hand

[shazeal]

99% sure none of the plugs are cracked, I just put the new plugs back in, re-re-re-re-aligned the crank angle sensor just incase lol. Completely ignored what the timing light said and adjusted the timing by ear, not exact but is how i used to tune motor bikes with my dad.
Seems to be running like it used to...
Seems like something somewhere is wrong as the timing light is giving me the wrong reading, ive no idea what.

As far as the steam goes... still has me worried a bit.
Ive had a head gasket blow on the water side before, twice once on my old escort mk2 which filled the sump with water plenty of steam all the time while driving. Other time was on my Escort mk4, which only had a small leak into the head, and it blew loads of steam, like a bloody steam engine lol.
On this car it only happens once the car is hot and is at idle, when driving there is no noticeable steam coming out. Oil doesnt have any white stuff in it either. Ill find a tester anyway as this is making me paranoid now

[CAMB01]

I had built a 4g63t engine out of an evo, owner put the engine back in, and assumed the CAS was where it was supposed to be, so never touched it. A week later it had steam out the exhaust at idle, but nothing while driving, when inspected had a blown headgasket, with pressure in the cooling system you could see water going into the combustion chamber through the spark plug hole. Found the timing was 45 degrees advanced

[shazeal]

Bah, now im even more paranoid. Ill have to check this tomorrow.

[matt dunn]

adjusted the timing by ear, not exact but is how i used to tune motor bikes with my dad.

Modern cars sound at idle great at around 30 degress as they love it,

but with computer control unless you set the ecu to timing set mode,( diagnosis mode) and do it with a light you wont even be close.

And even that isn't the full story, unless the TPS is set right it still wont go into base idle and timing mode.

Gone are the days where you twist the dist and listen.

Matt

[shazeal]

TPS is set right, and its going into diagnostics mode, the idle goes to 1k then drops to 800 same as my old NA car. I cant use the light as the reading its giving isnt correct, or if it is the timing of something is out. Gonna take it down to my local garage this morning and ask em to test the water pressure. Thanks for your help guys (crosses fingers that it aint a bhg )

[shazeal]

Ok took the car down to the garage and got the guy to test the water pressure, he pumped it up over normal and it sat there for ages before slowly returning to the normal pressure which he reckoned was normal. I bought it back home and then did the normal thing for clearing air out of the system, was no bubbles or excess pressure in the water once the car got upto temp.
Drove it for 30 mins got out and let it idle, no steam... head gasket is fine looks like.
Timing is still an issue as far as setting it precisely but its running really well with the final "timing by ear" i did last night.
Think im gonna have to look harder at the cam belt only thing i can think is it has jumped a tooth or was set wrong in the first place

Anyway thanks for all your suggestions, i learnt how to test the water pressure so thats something