Random Misfire

[Schwamm]

My engine is randomly misfiring (P0300), and I've replaced spark plugs to start with. I'm not sure if the root of the problem is a coil pack or spark plug wires somewhere, and I've only been able to test the two wires under the coil packs with a new part and that didn't fix the problem. Before I go spend money on different wires or a coil pack, has anyone had this happen to them or know what caused this, or would most likely cause this? Any easy way to test? I've heard I can use an ohm meter but I'm not sure exactly how.

 

[aubrandb3]

It is more than likely the coils. I do not know how to test them but i am sure there is a way.

 

[JB50]

Bump

 

[lyserjic]

Or, it may be you fuel pump. See my post about here:
http://www.mazdas247.com/forum/showpost.php?p=4331183&postcount=6

 

[yellowspeed1710]

My engine is randomly misfiring (P0300), and I've replaced spark plugs to start with. I'm not sure if the root of the problem is a coil pack or spark plug wires somewhere, and I've only been able to test the two wires under the coil packs with a new part and that didn't fix the problem. Before I go spend money on different wires or a coil pack, has anyone had this happen to them or know what caused this, or would most likely cause this? Any easy way to test? I've heard I can use an ohm meter but I'm not sure exactly how.

my car was doing the same thing and everyone told me to replace the coil packs, so I did and it runs and idles good now, so I would try that first its not too expensive, I think you can get them at Auto Zone for around 26.00$ a piece, Good luck

 

[chwood]

Bumping this thread - what would cause repeated coil pack failures?

I'm on my second set (including plugs & wires) in 6 months and the car is acting sketchy again like this set is going bad too.


For ref - I've got catless midpipe, corksport dp, hard intercooler pipes, (recently replaced) mbc at 9psi & AFC on stock supermap.

I DO think I've got a boost leak so I'm checking into that. I cleaned the EGR probably 10k miles ago.

 

[JDM Sam]

The factory coils are poorly designed.