Misfire from cold?

[markey b]

Anyone else have any clues as to why I get a slight misfire from cold? Did it before the nod is seems to start on 3 then then run for a bit before it smoothes out. Going to do valve clearances tomorrow but any other suggestions?

[Logg]

My car seems to start doing this to after changing to iridium plugs.

[B18ftMOJO5]

I thought i was just imaging it.ine does to. Clears up straight awa. Mines the b18ft though.

[TopCat]

My car seems to start doing this to after changing to iridium plugs.

Sounds pluggy to me too mate.

[casper]

My car seems to start doing this to after changing to iridium plugs.

I have also developed a missfire since switching to these plugs.:agree:

[Logg]

I have also developed a missfire since switching to these plugs.:agree:

I just put it down to the plugs not liking cold start up with a overly rich mixture. But after pulling away the first time the miss is gone.

[Brigsy]

Possibly too rich and sooting up the plugs. I also had this with a minor h/g leak

[markey b]

I run iridiums, maybe it's just normal. Tried normal plugs but misfired on boost

[casper]

Mine does it on boost,starts about 12psi.Got a feeling i gapped the plugs to 0.8 which could be the problem.First job when the weathers ok.At this rate:coffee: 2014

[michael tierney]

i had a misfire a while ago...turned out to be dampness in the dist cap....lying up too long!

[michael tierney]

i had a misfire a while ago...turned out to be dampness in the dist cap....lying up too long!

[casper]

i had a misfire a while ago...turned out to be dampness in the dist cap....lying up too long!

This could defo be adding to the problem in my case.:(

[Logg]

Mark now your running wasted spark have you changed the plugs to resistor ones?

The rest of you dizzy lads what plugs are you running? I use to find the NGK plus would start misfiring after six months or so of use. I changed to the copper campus champion plug and it was fine afterwards.

[tubbyG]

with the std dizy etc I use these

http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_19 4727_langId_-1_categoryId_165736

Have had no probs with these for over 1000 miles at 20+ psi, compared to my old NGK's :D

[casper]

Whats the number for campus plugs?ngk bp5es?

[Brigsy]

I still use b8evx...gapped to 0.5mm for high boost. Clean them occasionally but generally have no problems.

In my experience they arent very fussy when the mixture is rich.

[Tony Walker]

my denso iridiums do it most mornings but i dont have a choke i just blip the throttle while cranking, starts straight away better than my picasso lol but misses for 2-3 seconds? I presume it just fouls the first plug and runs on the other 3.
If i stick a new set of plugs in its fine for a few weeks then usually returns intermitantly.

[casper]

Well campus plugs have sorted the misfire out,seems to boost smoother as well,if thats possible?Only cost 7 quid for all four,thats 23 quid cheaper than the iridiu:agree:ms i took out.

[Tony Walker]

Well campus plugs have sorted the misfire out,seems to boost smoother as well,if thats possible?Only cost 7 quid for all four,thats 23 quid cheaper than the iridiu:agree:ms i took out.


Could you post the part number? make model? cheers.

[casper]

Could you post the part number? make model? cheers.

Ngk bpr5es.:agree:

[Mart]

Resistor type & heat range 5 wouldn't be my first choice of sparkplug to fit in a C1J, and even more so if running high boost.

[casper]

Resistor type & heat range 5 wouldn't be my first choice of sparkplug to fit in a C1J, and even more so if running high boost.

To be honest Mart not mine either,but they were recomended and seam to work well.:agree:

[gttjames]

To be honest Mart not mine either,but they were recomended and seam to work well.:agree:
was it colin on fb who suggested them wernt it?

[casper]

Have i put the wrong campus plugs in then?Should i have put the 6es in,thats the copper ones.I remember scoff saying to use n/a plugs from a campus.:confused:

[HAndy]

your plugs should be resistor type already, i think all irridium plugs are:), what heat range are you running, depending on what type of driving your doing mostly,ie cruising around town in traffic, odd blast @boost, try going back to a grade 7 plug, it will help with the cold start temps at the moment, and will warm up quicker burning of the carbon, what afr's have you got at idle also ,can you not lean it out a little?

if your sticking with the 8-9 grade irridiums at a guess? maybe close the gap up to a 0.6 or 0.5, this will help also;)


although if it where me , i would stick with a 7 grade plug. would'nt change to a 8 grade at very most grade 9, until you've got aleast 300bhp, rule of thumb is go up 1 grade of plug for every 100-150hp increase:)

are you using same ht leads? could it be one has broken down, change the leads around see if its the same cylinder missing?

of course if you have been running these plugs for a while and have carboned up before badly, and you have re cleaned them,chances are the plugs are ****ed already, and will need changing anyway:crap: they only withstand so much carbon build up/fouling then no matter how well you clean them ,they never fire correctly, oli's was proof of that the other week;)

[HAndy]

I run iridiums, maybe it's just normal. Tried normal plugs but misfired on boost


probabley knackered plugs or blowing out the spark, closing the gap would stop this also;)

[casper]

The iridiums i replaced were an 8 heat range.Im not sure now i have put the correct campus plugs in.?When people talk of putting campus plugs in there gtt,which one are they using.:eek:

[TNT ANDY]

interesting read hear guys - the heat range is in respect to 100's degree C?

[casper]

Luckily the bpr5es plugs i put in were cheap so im not bothered about changing them.So i dont need a resistor plug and the heat range needs to be colder s:confused:o what about ngk bp7es?I can get these today for 8 quid or the evx's for 25.Just cant see the point in spending that much on plugs.:sad2: