Misfire Question

[8Ball]

New member here. I did a search, but I am still a little unclear on 2 different cylinders misfiring. Any help is appreciated.

2003 Mazda Protege 5.

Running rough as hell. Pulled codes and get P0302 & P0303 which means cylinder misfire on cylinders 2 & 3 from what I have read.

My question is, would this most likely be the coil? I know it has 2 coils on it. Does 1 coil fire 2 & 3 and the other fire 1 & 4?

What would be the best way to troubleshoot this? Start replacing wires/plugs, or swap the coils to see if the problem moves to 1 & 4?

One last thing, the problem is not all the time. It has ran better and the check engine light cleared on its on, but it is getting worse and more frequent. I am not sure if the previous errors were the same, as I didn't have a scan tool until today.

 

[pasadena_commut]

My question is, would this most likely be the coil? I know it has 2 coils on it. Does 1 coil fire 2 & 3 and the other fire 1 & 4?

That's right. If the problem comes and goes check the connector going to the center coil, it might be loose or the connectors might be dirty. If you must replace the coil and you're not in a hurry you can get one for a lot less from Rock Auto than what you'd pay at the Mazda dealer. See the last few posts in this thread for replacement info:

http://www.msprotege.com/forum/showthread.php?t=123616443

 

[Black_Protege_5]

^^ I agree. It should be the coils. Check the connectors and the spark pug wire. On my stock wires I had a splice in it and the Idle was rough until I got the magnecor wires.

 

[Cellerator]

Check spark plug gap, if it closed in then it's a screw from the VTCS and it is under warranty from the dealer. It's quite annoying and always feel like it's going to stall, I had that a couple times before my dealer knew what was going on and they replaced it.

 

[blownoffvalve]

wow that was very confusing to understand

 

[Diehonda]

^which part? seemed fine to me.



Yeah switch the coils adn see if it moves to 1 & 4. Do a seach on coils and you will see a thread about tune-up information.

Factory coil part number is FFY1-18-100 and runs about $25 from what I have heard

www.rockauto.com has two brands - both under $20. I have a discount code for 5% off if you order before 02/28/2006 or go to http://www.msprotege.com/forum/showthread.php?t=123614937&page=1&pp=15 and around the sixth page people were confirming receipt of theirs from rockauto. Their discount code may go beyond 02/28/2006, so if you order after that just ask them if they can share the code.

Also do a search on VTCS and recall.


BTW Welcome (hi)

 

[8Ball]

Thanks everybody. I'll check it out and let ya know what I find.

BTW, really nice site you have here and very helpful members.

 

[Protege52003]

does your car idle like A$$ sometimes? check and clean your egr valve. i had a couple cyl misfire codes when mine was dirty.

-R