Momentary Loss of Power

[drgnzadiel101]

Per the first comment, the thread's name is "momentary loss of power" aka a misfire...

The battery going out will not affect power while the motor is running. The alternator can cause some screwyness, but it won't cause misfire-like symptoms.

on my honda it would cause the tranny not to shift correctly (automatics run on tcu), temps to rise all the way up, and lack of power. im guessing mazdas are a more simple and dont have so much stuff depending on electricity

 

[streetboi]

my friends jeep had a similar problem thats why i suggested a fuel pump. it didnt trigger a CEL and it only did it when the engine was running for a while. it kinda felt like a jaunt throwing you forward in your seat.

 

[ucMP3]

on my honda it would cause the tranny not to shift correctly (automatics run on tcu), temps to rise all the way up, and lack of power. im guessing mazdas are a more simple and dont have so much stuff depending on electricity

All moderately new cars have a lot of stuff depending on electricity. The newer the car, the more electrically dependent. But they don't use the battery while the motor is running. The alternator powers everything while the motor is running. The battery is charged by the alt, the electrical systems are powered by the alt, etc... Even if the battery is dead, current will flow through the closed system. (crazy)

 

[funkytuqe]

Crap, the car threw a CEL today. I assume it is related to the misfire, however it has been running top notch the last week or so. I will have to get myself a code reader and pull the code tomorrow and see what is going on.

 

[funkytuqe]

So i just reset the ECU and checked spark plugs. They were gaped to .035, so i re-gaped them to 0.044. I also finally installed the new plug wires that have been sitting in my garage for 2 months.

Took her for a rip and no more CEL, car still runs great (for now). I will just keep an eye on it, i have not had a misfire for a week or so now.

 

[funkytuqe]

OK, CEL came back today. I picked up a reader and i get P0300 Random/Multiple Cylinder Misfire Detected. That's the only code i get.

So that pretty much tells me that one of the coils is toast right? Wires spark plugs are new, i doubt the odds of 'multiple' plugs gone bad. Car still runs great though no issues in drivability for two weeks now.

 

[ucMP3]

OK, CEL came back today. I picked up a reader and i get P0300 Random/Multiple Cylinder Misfire Detected. That's the only code i get.

So that pretty much tells me that one of the coils is toast right? Wires spark plugs are new, i doubt the odds of 'multiple' plugs gone bad. Car still runs great though no issues in drivability for two weeks now.

What do your spark plugs look like? And yes, I would replace the coilpacks as was originally suggested.

 

[funkytuqe]

The spark plugs electrodes look like a light brown color, perfect i would say.

Just placed an order for new coils.

Does anyone know if there is a way to test the coil packs? I would like to keep the good one for emergency use in case i am stranded somewhere with a blown coil.

 

[ucMP3]

The spark plugs electrodes look like a light brown color, perfect i would say.

Just placed an order for new coils.

Does anyone know if there is a way to test the coil packs? I would like to keep the good one for emergency use in case i am stranded somewhere with a blown coil.

Um, you could to do a continuity test with a multimeter... But I'm not sure if that would really tell you anything useful, lol. I would assume a broken coil will still allow current to travel through it. Check the coil's resistance and whichever one is lower, I would guess is the good coil.

 

[slavrenz]

The spark plugs electrodes look like a light brown color, perfect i would say.

Just placed an order for new coils.

Does anyone know if there is a way to test the coil packs? I would like to keep the good one for emergency use in case i am stranded somewhere with a blown coil.

What I did when I tested mine to find out one was bad (I assume no risk for any injury or death):

With the engine running, I carefully slipped the spark plug wire off of each coil until there was a small gap between the coil and the wire. If the coil is working correctly, it should still be able to generate enough voltage to bridge this small gap with a spark.

Using this method, I found that one of my coils wasn't firing, so I replaced it.

 

[funkytuqe]

That's a great idea. Thanks!

Only thing is i'm not sure that will work since i think this in an intermittent issue and the car is running great, all power is there and mileage is still good, worth a shot though. I assume this would probably be best to do when the motor is hot since thats when coils seem to show symptoms more often than not.

 

[thecrash91]

actually when my coils were bad it was worse when colder

 

[funkytuqe]

Hmmm ok thanks, I'll check out both hot and cold conditions.

 

[funkytuqe]

Update: Changed both coils and no issues for the last two months.

Thanks Guys!

 

[jtlinna]

Sweet.

Someone should start making p0300 stickers for our P5s...


JT

 

[HKPRO5]

What I did when I tested mine to find out one was bad (I assume no risk for any injury or death):

With the engine running, I carefully slipped the spark plug wire off of each coil until there was a small gap between the coil and the wire. If the coil is working correctly, it should still be able to generate enough voltage to bridge this small gap with a spark.

Using this method, I found that one of my coils wasn't firing, so I replaced it.

I gotta try this out...