Hey, been hesitant to join this site as my '8 is just my daily driver. But I've had some engine issues I've not been able to diagnose by searching the forums and was hoping some of you '8 heads would be able to help me out, haha.

And by hesitant I knew when I signed up I would be having problems I wouldn't be able to research and solve myself..

When I first got my car from the dealership 2 years ago, I fell in love with it! I got such a great deal on it while looking for cars, I simply couldn't pass it up! 120k miles, one owner, new engine at 80k-ish miles, $4,999 out the door from Hyundai Dealer.

Anyways..! About a year ago, my car started having crank issues. From a cold start it would take a little bit to get the engine to turn over, eventually to where sometimes I'd have to let it sit for a minute to come back and try again. Also, after about 15-30 minutes of driving, it would seem like I would lose some compression, until I started from a cold start again. (Not as much acceleration as normal, very noticeable) I've dealt with this for a while as I could walk to work and didn't drive it much.

Now recently... I've noticed that I have a lak in acceleration all the time, and about a month ago, while trying to start the car, it wasent turning over, at all! Just the starter motor spinning! So I took it to the Mazda Dealer, paid the diagnostics fee, and was told I needed new plugs, wires, and coils; also should run Power Zoom Engine Cleaner.

I replaced the Plugs (NKG), Spark to Coil wiring (NKG) and all 4 coils (AC Delco). Followed this thread here: https://www.rx8club.com/series-i-do-...eaform-142852/ - Followed it as best I could with Seafoam Cleaner, even hooked the vaccuum lines to oil when I was ready to go through with the procedure to keep everything nice and lubed up!

Still had the loss of acceleration but it is manageable. Called Dealer about the trouble when starting and they said I probably have a water jacket leak in a rotor housing, takes a bit to start up but it burns off the coolant after its started.

Then is where the major problem happened... And I have searched all threads here on the matter and my story plays out differently... Was driving back from parents the other day, all full from delicious, delicious ribs... And the CEL started blinking, and my car was hiccuping with intermittent loss of power, the whole way back to my house. Like everyone else with this issue, I was freaking out! Parked, it starts up, rough idle ranging anywhere from 750rpms up to 1,600 rpms, when dropping from 3k back to idle I notice some back-fire and can smell heavy amounts of fuel...

Noting, that I replaced all plugs, coils, wires, and cleaned the engine, I also checked my MAF and filter box and everything seems to be in check. And I replaced everything about a week ago. CEL only starts flashing when driving and accelerating..


---TL;DR---


New Plugs, Coils, Wiring, cleaned out engine, Flashing CEL light, no problem with MAF. What are my options??

Sorry for the long first introductory post!! It's just when something happens to your baby, you don't have time to chit chat and wait 30 days to find a solution, I can't sleep! D:

(P.S.: Working on a project '91 FC3S TII, engine is about to be put back together, but problems with my '8 has stalled my work! Ever since I got my '8, I've become a rotor nut!!! Whooo!)

 

Catalytic converter might be shot? worth getting it checked out.

 

Well flashing cel is always a miss fire but i think you knew that.

I don't have a clue with your troubles.

Are you burning oil? Fo you premix? Hows uour coolant level?

 

Yeah, when I looked it up misfiring made perfect since when compared to a piston engine.

Replaced the radiator about a year ago, when I did all the work a week ago I did notice my coolant was a little low so I topped it off with 50/50 antifreeze. I don't premix, but I do use 5w30 Royal Purple when she does start getting low. Changed the oil filter about a year ago and when I did that I also mixed some Lucas in with the 4 quarts or so.


I hope its not a CAT problem, I had all the wires I was supposed to have unplugged when I did the engine cleaning, but it did say if they weren't unplugged it would kill the CAT.. So thats the only relation I can see, it doing this after only a week.

Could the MAF somehow be malfunctioning, and would it fit the symptoms? As I said, it looked clean and I have cleaned it out in the past, but I guess anything can go bad at will.

Also, possibly useless info, but I also swapped the ESP sensor when my car wouldn't start before I took it to the dealer, it was used at that. I didn't put the original back in but I dont think that would have anything to do with misfiring, but I don't know...

 

If you do anything ignition or belt related the ESS profile needs to be reset i.e. search "20 brake stomp" procedure.

Recheck your ignition work and make sure you reconnected all coils & plug wires properly.

Possibly clogged/damaged cat converter. Unbolt at exhaust manifold connection and look into cat pipe with a flashlight to inspect cat entrance for failure.

Possibly water jacket failure getting worse (and/or it will eventually). Have coolant system pressure checked.

You should always unbolt the cat converter when doing an engine cleaning. Otherwise excess cleaning fluid goes right out the exhaust ports into the manifold and ultimately into the cat converter. Plus on start-up and running afterward you will also be contaminating the cat converter if you have it hooked up. If there is excessive cleaning fluid in the exhaust it can light off and damage the cat on start-up too. People don't seem to realize most of the cleaning fluid goes straight through the engine and out the exhaust. So if you pumped the whole can through 95% of it ends up sitting in the front exhaust section unless you open it up at the manifold outlet connection and let it run out instead.




.

 

I will try everything mentioned above in order when I get home today. I'm still learning as I go when it comes to car maintenance in general. I did a lot of research before doing the engine cleaning but didn't see anything about actually removing the CAT. Makes plenty of sense though. Luckily where I'm at there are no emission regulations so if I have to have the CAT off for a while then it wont bother me too much, just make driving a little louder.

As said before, I will try all steps when I get home, and get the coolant pressure checked when I get some time off from work. Thanks!

 

You changed the oil filter a year ago? Aren't they like ten bucks? Those are disposable, and should be done with every oil change.

 

Alright! Cleaned the MAF connector and sensor again. Couldnt find a 10mm driver for the ESS... So I sprayed a bunch of brake cleaner all over it from where it was held in place. Checked all the wiring from the spark plugs to coils, everything seemed to be in check. Couldn't drop the CAT as I couldn't find a 10mm to remove the O2 sensor with.

Put everything back together, and voila! No more misfiring!!

Still concerned about code P0661, doe's anyone know how any three of these solenoids affects the vehicle, specifically performance?

Car accelerates like crap i.e. half of the torque its supposed to have. I am gonna try to get all the proper tools from work to drop the CAT and see if its clogged up!

 

Well, started up car this morning, drove an 1/8th mile down the road. Misfiring again... Not sure what could be going on now.. Gonna poke around again after work I guess.

 

And another update. I did some other maintenance as well while I was all in the mood. I removed the Fuel Pump and cleaned out the sock filter. Also, removed the UIM and got back to the three solenoids for SSV, VDA and AIR.

I didn't have a conventional way to test them as it required plugging up a 12V line and gound to test to see if they were functioning properly. So... I took some alligator clips, hooked them up to a 12+V and GND in my desktop PC and tested them. Turns out the solenoid hooked up to SSV was bad!

Browsed around the forums to see which one was least important (until I can get it replaced) and found the AIR isnt essential to engine performance. Swapped the solenoids around, went ahead and cleaned everything I could reach with brake cleaner and assembled everything back. As per another thread, I held the tripometer down while turning the ignition switch to ON, and then did the 20 Brake Depress again to reset everything.

I took it out for a spin and I am still having misfiring...! Not sure what to do at this point. How likely is it that one of the coils and/or spark plugs could be bad a week after replacing them? Any more thoughts?

Thanks!!!

 

I know no one is really interested in this thread anymore, haha. But I got her up and running finally! Runs better than I ever remember it being!

Turns out a coil had actually gone out a week after I replaced them! A friend of mine said a bad cat could do that which would make since it being extremely clogged and all. So in the mean time before I get either a straight pipe of another cat, I gutted mine out and put it back in place. Put more seafoam in the tank as well.

I reset the ecu again and drove it around in a parkinglit carefully for 15min so it could relearn. For a 4port motor, this thing feels fast and responsive, I loooove this car again!!!!
163K miles and she is purring! My family and friends are trying to convince me to sell it right now while its running, but the RX7 I got lasted 276k miles before having a major oil leak (original motor still running). So im hoping this guy could last another 20k to 40k atleast.

Thanks again for suggestions!

 

Glad it worked. A DOA coil is not where I would have looked first, second or third.