RXh8love

Hey guys, i am super new to the forum and the rx8 club in general. I am having some issues with my rx8. Any help or input would be appreciated and i apologize in advance if the questions are stupid or maybe answered before but i wasnt able to find the answers. The car is 2004 AT with 130k on the engine. Its got a greddy catback.other than that stock everything. Car was starting ok hot and cold. Hot obviously a little slower but never issues or never not starting. I was doing maintenance as per research decided to change coils plugs and wires. Changed those. And my hot start actually got a lot worse( not sure why).
i got no current codes except for the rear o2 sensor. Sometimes it throws the p0076 control solenoid bank 1 circuit low( i cant find info on how this affects the vehicle, and i dont always get that code, any input?) I also sometimes get the p0171 system too lean code, but again it doesnt happen all the time( where do i start looking for that from research i am seeing i might have a vaccum leak somewhere?).
The issues i am experiencing with the vehicle rn is rough idle, when warm. When cold it idles great no issues as soon as it warms up rpms dip below 1k and it starts vibrating a little, rpms dont really move up and down but the car is vinrating a bit, it vibrates even more if i throw it in reverse and rpms dip to around 500. I also now experience rough hot start where the car wont start when hot until it cools down, from cold it starts np. I def dont baby the car and rev it every time i drive, the car feels underpowered in 1st gear at high rpms, just doesnt feel as snappy and lacks torque. I took it to mazda a while back and they checked the it said the compression is fine even tho they didnt give me the numbers so i dunno whats fine to them.
I do still have an old starter so i was thinking thats where i need to start at least to help with the hot starts because starter feels like its cranking slow.
i cleaned MAF it gives 5-6 g reading at idle. Cleaned throttle body. Was thinking maybe seafoaming it, what you guys think? Any input appreciated!

CaymanRotary

Did you try reinstalling the old parts you took off? What brand coils did you get? When you also changed the spark plug wires did you ensure they were run properly between the coils and spark plugs? Not being able to hot start could mean your compression is low. Would be a good idea to compression test it anyways since your milage is pretty high. Also possible you got defective coils and that's why it's not running right. The main thing on this car is running tests.

Also read the new and potential owners sticky on this forum. It will help you out a lot.

RXh8love

thanks for the input, i didnt try putting the old coils back, maybe i will give it a shot this weekend just to see if it would make a difference. I got the d585 performance coils. Also a dumb question but does it make a difference where you ground your coils to? I grounded mine to the battery ground. I did check the connection to make sure the plugs attach to right coils. I was wondering if say one coil was an issue would it affect only hot start or it would affect hot and cold?

CaymanRotary

ok, this makes a lot more sense. The d585 coils are brilliant but the dwell on them can cause starting issues. You may need a Cobb accessory tune to get them to work a bit better. I always just use OEM Mazda coils and never have an issue. Found a thread that can explain it better than me.

https://www.rx8club.com/series-i-aft...-dwell-241134/

Edit: what brand of d585 coils did you buy? You want Delphi.

RXh8love

i am actually not sure what brand they are cause i bought a kit that someone recommended this is it
https://www.npboosted.com/collection...-wires-bracket

CaymanRotary

Cheap coils that look better than they work I'm afraid. Delphi are the best from what I've read. I'm just happy with the performance I get from OEM so I doubt I'll ever personally install these. Good news is at least you can reuse the bracket but I would get better wires and coils.

RXh8love

ok i will try and install the old ones maybe tonight and see if it changes anything. It would suck cause they r brand new but whatever.

CaymanRotary

The worst part about these is they are already quite expensive. So you would think the quality is there but it just isnt. Dont worry, you arent the only one who's paid big money for bunk coils (I've done the same lol).

RXh8love

oh i bet. having this car is worse than having a gf. Biggest attention ***** and endless money pit. I spend more time researching and fixing this thing than i do on my relationship.

CaymanRotary

It's an exclusive club to be a part of at least! Feeling your pain right now man... could try the spark plug wires though they may be ok so all you'll need to replace is the coils.

RXh8love

its those deceiving good looks, they get you every time. Ok thank you for your help, i will try installing the old ones tonight, if it fixes the issue i will order a new set and report back go from there. Also if anyone knows anything about this solenoid issue and how it affects drivability? The dealership said i dont have to do it right away and its not a big deal, but i dont really trust em too much, their diagnostic goes as far as scanning codes.

CaymanRotary

Is it the p0661 code? Those are the three solenoids by the firewall and yes, they affect drive-ability.

edit: Noticed in your original post you had the P0076 code. Here is a thread that goes into better detail to help you diagnose it.

https://www.rx8club.com/series-i-tro...nk-1-a-193398/

bluetii

iTrader: (3)

I too had D585 coils and had issues. Went back to oem or NGK and been running great ever since.

RXh8love

Thank you for your replies guys. I will look up the link on the solenoid i think from what i gathered its the vdi solenoid. Its a cheap part and i should probably just replace it but i dont trust myself to take off the UIM to get to it, but might have to suck it up and do it. Either way coils or not i should replace it. Hoping switiching the coils will resolve the issues somewhat. Appreciate the help

CaymanRotary

Anytime. good luck! If you are removing the UIM to replace solenoids you may as well change out all 3. If one is gone the other 2 are likely not far behind.

RXh8love

I am just not confident id put it back together lol, taking it off wouldnt be the hard part. So i put the old coils back the idle is still rough, but the car started from warm without a struggle. Now when i start it, the rpms start at a 1000 then slowly drop down to about 500 car feels like it might stall but it doesnt and they climb back up to about 700 or 800 and stay there, car still shakes a little.

RXh8love

Go for a drive just now cel is flashing p0301 cylinder missfire. Fml

CaymanRotary

it’s likely those coil packs are bad. If you want it to just run right get Mazda Rev C Coils directly from Mazda. It’s all I ever run and all that’s really necessary. Either that, or run Delphi D585’s.

UnknownJinX

If you think an RX-8 is a money pit, just talk to a BMW enthusiast. Trust me, you will feel much better afterwards.

Rev C is okay, but just like any revision before it, I would still keep an eye on them after, say, 20k miles if you are not tracking. Supposedly some people still have them fail.

As for D585 coils, this just looks like another old BHR copycat. I am not going to go deep into the whole business ethics part of the matter, but if you aren't buying the original(which, if anything, at least has decent customer support), it's a bit of a hit or miss. BHR also overhauled their design so it can directly replace the OEM coils.

RXh8love

Alright so the old coils start the car better from hot, but when i accelerate first 2k the car barely moves engine throws a missfire until it goes into the higher rpms then the car drives fine, i switched to the d585s again no missfire but the car struggles to start from hot. Thinking i am gonna get another set of coils at this point and see what happens.

CaymanRotary

You either need the Delphi D585's or Mazda coils. That should solve your problem. If it doesnt, I would recommend doing a compression test.