warbick

My 8 stranded me the other day after I shut it off to grab some coffee. Came back out and it wouldn't start. Had it towed to Mazda and it fired right up for them. Then they pulled a 30301 misfire code. Looking around here, it seems it's actually a P0301.

The problem is, they can't figure out what is wrong with it. Plugs, coils, and wires are all good according to them, and I replaced the plugs myself this past summer. They tested the fuel pump and said that is fine, and the cat is fine according to them as well.

I'm going to pick it up tonight. They said they replicated the starting issue once, but found out nothing and haven't replicated it since. I have searched all over the place and a few others have had similar problems, but no answers were shown that have worked for me (I also reset the ecu as suggested).

Anyone have any ideas? Am I dealing with an incompetent dealership? There is another that isn't too far away, I could take it there I suppose. This is my DD, so I really need it working properly.

rickeo

iTrader: (1)

Do you know when the coils and wires were changed last? Are they originals? What year is your car and how many miles are on it?

warbick

2004, about 56k miles. I do not know when the coils or wires were changed, they easily could be the originals, but the dealer says both are fine. I went to pick it up today and it started fine, but the CEL is still on and I have a slight hesitation issue when pressing the throttle. I left it there so they can look at it Wednesday.

xexok

According to other threads and I believe teamrx8 the way Mazda tests the coils is not the best way. Your best bet is to buy coils yourself and install them yourself. Buy coils and wires from Mazmart for OEMs or advance auto/autozone/checkers for the cheaper brands. You will get completely and totally ripped off if you have the dealer do it, not just a small markup but a crazy amount.

warbick

Thanks. I have been thinking exactly this, as they seemed to not be completely sure in their own coil test. I have been looking at some BHR coils but man, they are expensive. I don't think I can justify almost 5 times the price of OEM. I will give Autozone a call or maybe hit up Mazmart.

I will search for a DIY but I'm assuming coils/wires are not difficult to change?

j9fd3s

coils and wires are very easy. coils can be changed by removing the little box from the intake tube, do one at a time, should take about 15minutes.

shop around for prices, if you look you can buy pretty inexpensively. save the old coils, you might need them to diagnose something someday

xexok

Just the oem coils from Mazmart are $240, the BHR kit starts at $500 so is pretty much double the cost of oem. The BHR kit also includes new wires with it so that is another thing to consider. You can go with cheaper alternative coils from auto part stores and pay much less than oem if you want, many people do.

TeamRX8

iTrader: (25)

use your head, which means consider the source because there are a bunch of numnuts around here who think snapping off parts buying replies without the proper diagnosis is the right way to do things

1. Reset the ESS profile/NVRAM (search brake stomp procedure)
https://www.rx8club.com/trouble-shoo...memory-169443/

2. Clean ESS (eccentric shaft sensor)

3. Test coils and plug wires
https://www.rx8club.com/do-yourself-...-wires-222641/

4. Inspect spark plugs

5. Inspect cat converter for plugging


in general this is referred to as a misfire condition, there are literally hundreds of threads on the subject but this one is the most comprehensive

https://www.rx8club.com/tech-garage-...t-here-222280/

sometimes it just happens especially in a non-start cranking situation so don't go overboard unless the code keeps coming back

warbick

Thanks.

I have already done all of the above aside from the shaft sensor and actually tested the coils (but mazda did). I'm fairly certain the coils are originals and it's time for them to go. I'm picking up some from the local auto parts store for about 29$ each. If that doesn't work, I'll take it back in but still have new coils anyway.

Thanks everyone for your help.

warbick

Just to update, the coils fixed my issue entirely. Feels like a new car!

warbick

I did also clean the ESS while I was already there. Could have had at least something to do with it.

wcs

iTrader: (2)

Thanks for the update