What colour spark?

[imp124]

Hi

i had all the plugs out today, just bought some new ones as the ceramic was cracked on the old ones, i earthed the spark plugs and they gave out a yellow straw coloured spark, when i had my bikes i was told this colour spark was not good so i was wondering if this could be the reason for my misfire?

So far i have changed:

Plugs

HT leads

Cleaned Dizzy cap + arm

Changed coil

i have also had a spark plug on the HT going into the dizzy and this produces a straw coloured spark also, the spark gap is ok, any help please??

Steve

 

[ollyc98]

Was the earth good, my sparks have always been blue. Is it the electronic dizzy or the points type?

 

[imp124]

the earth was good but i dont know if the dizzy is electronic or contacts someone else might be able to tell us, and i know what your going to say if it is the contact type .... i will clean the contacts and check the gap etc... makes sense actually if it is

also how would i go about checking the coil with a multimeter? and what readings should i get?

Steve

 

[imp124]

just been looking at the engine code for the ST and i believe it is MA09ERT?

if so i have also been doing my homework on the engine codes

correct me if in wrong but MA09ERT = MA (micra/march engine) 09 (930cc) E (electronic fuel injection) R (supercharged) T (Single turbo)

If this is correct i believe this means that the dizzy is infact electronic?


ALSO does the ECCS system with the ECU have fault codes that can be read with a diagnostic?

Steve

 

[frank]

the R is supercharged steve, and it will be electronic (it has an ecu eh) is the missfire on 1 cylinder (ie, have you tried pulling the leads off, one at a time ?)

 

[imp124]

i have not yet tried this but the misfire is intermittent as in it does not happen on every cycle only sometimes but often enough to happen at least once every 5 seconds

i have also been looking up on the ECCS system does it have a self diagnosis system as some people are saying that the fault codes can be read out on the red / greed LED's

RED = 10

Green = 1

make any sense to anyone?

cheers

Steve

 

[ollyc98]

Oh it's for the ST, will of course be electronic, how stupid do I feel lol.

 

[frank]

i have not yet tried this but the misfire is intermittent as in it does not happen on every cycle only sometimes but often enough to happen at least once every 5 seconds

i have also been looking up on the ECCS system does it have a self diagnosis system as some people are saying that the fault codes can be read out on the red / greed LED's

RED = 10

Green = 1

make any sense to anyone?

cheers

Steve

i would guess 2 red flashes = 20
2 green flashes = 2 , etc ?

 

[imp124]

yes that is what is floating about the internet but this is in regards to different cars (not the ST) but the fault codes all appear to be the same just dont know if the St has the internat fault code read off lamps etc?

also is the dizzy cap from a Figaro the same as the ST?

 

[SammoHung]

jumping back to the original question (spark colour)

-> yellow straw spark colour does not always indicate a fundamental problem...

this could be caused by either:

-a genuine ignition fault
-the air that the arc is forming in (environmental conditions: temperature and humidity)
-contamination of the plug electrodes
-change of circuit impedance as the arc forms...(dont ask)


....is the misfire still there with your new plugs?
....are you CERTAIN that it's a misfire (not just a late angle fire or a fuel transient?)