NB: No spark on cylinder 2 and 3

[Ziox]

It all started this winter, when I started the engine it would run rough. At first it was not that much of a problem because it would fix itself in a matter of seconds and not happen very often. After a few days it became a more annoying problem, it would not fix itself straight away and sometimes i would need to rev the engine a little bit. Days went by and things became to get worrying , to a point where i didn't want to run the engine afraid to ruin the cat and other parts in the engine. I started to check what was wrong and narrow down what i needed to search for on the forums. I checked the spark plugs first, and plug on cyl. 4 was covered in oil. I changed all 4 spark plugs to check if that was the issue. At first I thought it fixed it, because it ran smooth after that.

But after one and a half week it came back and more frequent. I eventually found out that it had to be no spark on Cyl 2 and 3, because when i removed the plugwires on either of them it would make no difference on the engine, and when i put the wires back in it would fix itself. So i thought the plug wires was the issue, after replacing those with high quality ones the problem disappeared, but only for a week. And today i drove the car to a mazda dealer to have it diagnosed (drove it 100 meters on low RPM, luckely i was right by it.) That costed me 180$... And what result did they get? Nothing, they just said that my car had a foult code (1345) and they recommended changing coil, which I dont want to gamble 380$ on without knowing 100% is the issue.

Info about the car:

• NB year 2000
• 109.500km or 68.040miles
• last service 105.000km or 65.250miles
• 1.6 litre

Other helpful info:

• Had a problem with stalling and missfire a year ago, problem was a loose CPS (cam position sensor) Not tighten or have come loose
• Did check the CPS today
• Had a noise problem earlier but this is no longer a issue it dissapeard by it self. CHECK OUT: http://mazdaroadster.net/showthread....705#post164705

If there is any more info you need to narrow it down, please tell me.

Here are some pictures i took of things that can have something to do with this problem (dont know if its sweating or leaking:

[Demon I Am]

Here is my saga on a very similar problem: http://mazdaroadster.net/showthread....need-some-help

TLDR: Faulty wiring on the coil pack wiring connector. Try running the car, and jiggling the wires connecting the coil pack on the drivers side. Having a timing gun that reads spark pulse makes this easy, try to rent one or borow one if you can.

It's an infuriating problem, but I hope you find your root cause

[Ziox]

Tried to jiggle the connectors and wires on the back of the coil, no luck D:

[Demon I Am]

Order an aftermarket coil pack for $80. http://www.amazon.com/gp/product/B00...ilpage_o00_s00

[Ziox]

Okey, I talked to someone from Canada that have been working on old cars. He asked me to open the fuel cap, I have allways known that the cap makes a vacuum noise when I open it but I never thought it was bad. Could that cause that kind of problem with the engine? I will try to open the cap next time I start the car and it runs on 2. Just ordered a coil :S

And by the way, the car does run good as long as its on, the issue only appears when i start the engine. And not every time i start it.

[Ziox]

I have another question, will a problem in the EVAP system cause these symptoms or gas cap?

[NobleRogue]

You should be hearing air "escape" when you loosen the fuel cap. It is a pressurized fuel system. If you hear a vacuum sound then there is a chance that you have an Evap problem. And low fuel pressure can cause misfiring. I'm working on a misfiring problem as well. The problem is that there are so many things that can cause it to misfire that it can take a long time and a lot of money to track down. Considering that you have oil on the number four spark plug, I would do a compression test. Wet and Dry. This can tell you if you have bad rings, carbon build up or a bad head gasket. Look on youtube.com for videos on how to do a compression test. If you do not already know how. You can get a gauge at Auto Zone for under $30.00. I would also check the PCV Valve. It could be leaking oil in to the intake. If this does not help you solve the oil on the spark plug problem, do a leak down test. there are videos on youtube.com that will tell you how to do one. You may also want to get a shop manual. A list of issues that can cause a misfire. 1. Bad fuel pressure caused by a weak fuel pump, clogged fuel filter, leaky fuel lines, faulty fuel injector relay and bad fuel injectors. 2. Poor air flow caused by a Faulty MAF censor (Mass Air Flow), clogged air cleaner or debris in the intake manifold. 3. Bad or unreliable spark caused by bad pugs or plug wires, bad coil, faulty crank position censor and a faulty cam shaft position censor. I hope this helps. I know it can seem a little over whelming. But once you fix it, it will be worth all the work and time.

[Ziox]

Changed coil 2 weeks ago, no sign of any problems yet. Thank you all for the helpful feedback!

[Demon I Am]

Awesome. I hope that was the culprit!

[— freedomgli —]

I figured it was the coil. When two cylinders running from the same coil are both experiencing misfire then it's usually the coil or the coil wiring. It's a pretty common NB issue.