I've just begun to resolve a misfire problem at idle. I have replced aftermarket plug wires with Mazda OEM. I just checked the plugs and will have to admit that before getting the FSM I just duplicated new NGK plug placement (L & T) that was in the car when I bought it.
However the plugs I was given at NAPA were the correct BUR numbers but they ended in "P". Example BUR7EQ"P", BUR9EQ"P".

Today, with a bit more smarts, I have found that the leading and trailing plugs were reversed in both rotors I have three (3) relatively dumb **** questions.

1. Could the "P" at the plug type contribute to the misfire? What per chance does the "P" mean anyway?

2. Would reversing the L & T plugs in both rotors contribute to a misfire, and:

3. Do I check TPS next if new wires and correct plugs does not stop the misfire

Thanks... Jerry

 

If new wires/plugs did not stop misfiring, check your CAS and coils. Make sure the wires are snugly mounted.
Also, get your fuel injectors cleaned. Check your fuel pressure and replace the fuel filter if you have never replaced it.

P = platinum. Since I need to change my plugs every year, I haven't noticed a difference between P and non P plugs. I swap back and forth depending on whats available.

Since it is summer time, I would doubt that the misfire was caused by plugs in the wrong position. When I bought my car, it had two trailing in the front rotor and two leading in the back rotor and the car ran perfectly.

I also don't use the plug washers. This puts the plug closer to the air/fuel mixture and the car seems to run stronger. Some people say that the plug could get too close to the apex seals and trash the motor. I would hope that Mazda made the plugs 'idiot dealer tech proof' since they were the ones that installed the above mentioned plugs incorrectly.

How bad is the misfire?

 

LEAVE TO PLUG WASHERS IN!!!

i took this advise not from deadconv but from another user and after a while 10k or so miles i noticed a little film on my plugs??? well it started getting worse and eventually they were soaked in oil well i put in mew plugs due to the oil they were getting fouled quite quickly this time though i was too lazy to take off the rings well i went to check them on the next oil change to see if i should replace them yet and lo and behold no more oil on the plugs? so just a word to the wise it DOES help i DID feel a difference in throttle responce. BUT, it also made my plugs fould because they are to close to the oil control rings with out the plug ring.

just my experience
james

 

Explain that.
The washer has no say on whether there is more or less oil on the spark plug. The closer to combustion, the hotter it gets and is more likely to stay clean.

The only time that my plugs ever fouled is when driving like a wimp or when taking lots of short trips and not fully warming the engine up. I think that you need to exercise your engine some more.

 

I highly doubt it - the "P" means "Platinum" and just lasts longer.

YES!!!

We need more info...


-Ted

 

not that they were getting fouled by carbon they wer getting foulde by oil coated by it so much that they no longer liked to work