Technical Spark plug check

[fiatmultiair]

Hello,

I bought a car that did not have any history of maintenance, I wanted to check the spark plugs first so I can get a ball park of whats going on. To me it seems like it's a rich mixture fire in the engine but I would like your opinion.
Engine is Multiair 1.4 turbo, these are denso plugs and I switched them to NGK Laser Iridium ones.

 

[bugsymike]

According to my 2012 manual ( I don't know what age your model is?) the Multiair1.4 Turbo is listed as having NGK IKR9F8 spark plugs, in my manual it only gives the plug gap for the non turbo version of 1.0mm(40thou/inch) looking at the photos I would have said the gaps were much wider, but more to the point if the plugs are that colour after a good run then I would say it was running rich or the journeys you make are not long enough for the engine to warm up and clean the soot off themselves.
Maybe other Forum Members can advise?

 

[fiatmultiair]

Model year is 2009, my plugs came in pre-gapped and I compared the old ones to the new plugs and they were the same.
I suspect that this is running rich, and I need advice on how to resolve these issues, hopefully it's not a costly repair.

Also, I don't think my local mechanic is capable of figuring out if it's faulty MAF sensor, O2 sensor, or MAP sensor. If anyone has had simular issue let me know.

 

[bugsymike]

The details I gave were from a Auto Data Technical Service Data manual and cover from 09-2012 with engine series no. 955A2.000.
Are you able to read any Error codes stored or pending in the cars ECU to give a possible guide to the problem.
Have you checked for other things that can affect it such as blocked/dirty air filter, slight air leak /loss on the turbo pressure side, pipes/intercooler etc.
It may even be something as simple as due to colder weather or even a thermostat opening early or short journeys that the engine is not getting hot enough to run efficiently. All these things can increase fuel consumption and show on spark plugs, as running richer/sootier.
A good run with the temperature gauge showing in the middle followed by inspecting the spark plugs may give a better idea regarding that side.

 

[AndyRKett]

I'm kinda inclined ot agree with Mike those gaps look to big. I have just cleaned and gapped all the plugs in my car. 0.9mm gap and they look way bigger.

Big gap = weak spark = incomplete combustion = black plugs. I would start with the basics and work backwards from there.

Also if this is a car only ever used to commute to and from work, or lots of short trips, and never given a proper run out at higher speeds and higher RPM then that can lead to carbon build up over time, it may benefit from being driven like an Italian car for a day or two, that is to say, you're not driving it properly unless the valves are dancing on top of the bonnet.

Fancy expensive spark plugs are often not worth the money and add nothing.

 

[varesecrazy]

Bearing in mind that it's an unloved Multiair..

There Is always chance of fuelling correction problems

 

[AndyRKett]

Bearing in mind that it's an unloved Multiair..

There Is always chance of fuelling correction problems

Multiair filter? is it the inlet side that multiecu runs on ? I’m sure if there were issues on that side of things there would be an engine light ?

 

[fiatmultiair]

So the past owner did not really care for the car much. Multiair unit was replaced 1.5 years ago, he mentioned that the service was also done 1.5 years ago, also right before he sold me the car he done turbo maintenance and exhaust maintenance, so these sparks were working during all those issues. Also, I found out that these sparks were fake potentially as the fit and finish was half a**ed. Running new plugs shows me some improvement but nothing big, it's just noticeable. I do need to change the O2 sensor as well, which I need to find a part for it and find a way to do it as our official fiat service is absolute garbage.