Moon Buggy

Hey here is one for the RX8 tech-Einsteins. Need your help guys.

My RX8 is 4.5 years old and ran fine until I had strange problem : there is an obvious lack of power (middle revs range - 2500 to 6000 rpm), almost no torque left. There is no better way to describe the problem as the feeling you'd get from accelerating strongly on an old motorcycle with manual shoke on. Like a carb with a too small injector or so (please forgive my descriptions, I'm not a technician as you can see).

So, I placed car in garage to be fixed and it has been stuck there for 3 weeks... and THEY JUST CAN'T FIND WHAT IT IS. They agree that this lack of power is obvious and not normal. Even national Mazda specialist came and checked the car... no clue so far. Computer was reading all as being OK.

Here is what they did : checked compression of engine, noticed it was in the acceptable factory limit in terms of compression and so... replaced the engine (under warranty... phhheeew!). They also noticed the catalytic exhaust was to be replaced and changed it.

NO RESULT AFTER THAT. Still same power problem.

Then, they figured out that the injection command could be mislead by the PCM and replaced it.

NO RESULT AFTER THAT EITHER. Still same power problem.

I'm kind of desperate about this being fixed. Any of you have hints or heard about similar problem... and solution?
Thanks in advance.

I miss the revs, guys.

Easy_E1

iTrader: (2)

Ever change the fuel filter or pump? How about air filter? Only other thing would be bad coils. Did they check them?

dannobre

iTrader: (3)

WOW..talk about throwing parts at a problem

I assume that they replaced the small block and swapped over the intake/injectors/ sensors/coils etc??

If that is the case...I would start checking the /coils/sensors/injectors..and the wiring harness..that's about all that is left

Moon Buggy

@ Easy_E1 : I don't think they did change the fuel filter, pump or air filter. I presume they at least checked the air filter, but I'll ask again! (never know, right!) - The coils seems to be the best guess.

@dannobre : good point, after coils, sensors and injectors are about all that's left to be checked, right! I'm just wondering why that "computer-check" in garage says all is fine (but I have no idea about the relevancy of that "computer-check" they keep telling me about).

Thanks for your views, guys... I'll keep you informed about the next tests and responses.

whg690

Hey, i def am not a tech and you can take my advice with a grain of salt, but my rx8 was doing the same thing and it turned out to be carbon build-up in the engine...decarb kit and all was as it should be...

snowflakes

iTrader: (4)

^ but he said the engine was replaced... so i dont think it would be a carb build up problem, u knoww what i mean... but the only thing i can think of is them replacing the WHOLE ECU out. even though the Ecu is reading normal and all is fine as you said,but there is a possiblilty of a problem occuring while it is on load well besides the fact that they "said" the ecu is fine they should still replace it....if not they should just give you a new car lol :P

Moon Buggy

Okay guys here are the morning news after long call with garage :
They are currently RE-checking the injectors.
OK, maybe it's the steering wheel... geeee, I just can't believe this crazy situation.

PS : BTW I use the term PCM because the guy at the garage used it but I think we're talking about the ECU (aluminium box looking like a computer internal hard drive, the "computer of the engine", right?). So we do have a new one too here.

max5roadster

No sticking intake manifold valves? hmmmm.... TPS? or maybe a faulty throttlebody ...

nmarz77

I just brought my RX8 in to the dealer on friday for the same exact problem. Power loss below 5,000 rpm on mine. They already flashed the PCM and checked compression. Compression was good. Service writer is saying they might replace the engine, though I feel it's probably an ignition problem. I will know more sometime Monday.

Chadwisk

iTrader: (5)

https://www.rx8club.com/showthread.p...ighlight=msp16


hope this solves your problem

nmarz77

Yeah they already flashed the pcm with the update and there is still a problem.

Moon Buggy

@Chadwisk : Thanks for the thread link... I suppose I shouldn't be in the same circumstances by now, since both engine and PCM were changed.

@nmarz77 : Well... seems we're in the same hallway. Before they do so... please know that even with new engine problem remains.

NEWS OF THE DAY :

OK guys, listen to this... Friday I got a call from the head of garage mechanics (I know him and he is a dedicated honest professional that I respect). He told me he had found the power problem source. Apparently it was coming from a problem of instruction sent from PCM to one of the injectors. He was happy and said that the car was giving the boost like a brand new one. Than he said he still had few error codes sent by PCM and was going to check it out over the weekend (talking about dedication... he's a great guy).

Today he calls and says... "I'm really desperate. After driving the car and checking the codes for 2 days... I'm getting loads of new error codes now. Power is back but there shouldn't be codes like that and I can't find what causes them. I'm left alone with this problem. Could you please call MAZDA Europe?"

Thing is the guy called MAZDA Europe 3 weeks ago to get help from an engineer and they didn't seem to move so far... (this is the 4th week my car is locked into the garage).

This is enough now... I'm calling them. Let you know more later.

nmarz77

Damn, sorry to hear that man. I hope I don't end up in the same boat as you are in. I don't think I can handle much more time without my RX8.....the weekend was hard enough. The service writer is talking about an engineer coming out to take a look at my car too.

nmarz77

Well, I was notified yesterday that they will be replacing my engine too. They performed the flash, compression was good but they still de-carbed the engine, only 5 random mis-fires were detected. Car was still lacking power under 5k.

Hey Moon Buggy..... did yours have a long crank before starting?

~0zzygirl~

Moon Buggy... some people have had to have their PCM replaced b/c it went nuts. I'm no expert but you might try researching that and see if it sounds like a possibility.

nmarz... I don't know but if it doesn't fail compression I wouldn't let them take out your engine. My 8 was a rape victim and it's never been the same... make them exhaust all possibilities before they replace the engine.

My 2 cents.

shaunv74

Catlytic Converter clogged. Have them physically unbolt the converter and inspect it. It can get too hot melt and clog up.

It doesn't always throw a CEL code but is a common reason for lack of power. It may need to be replaced.

We see it a lot in the states.

nmarz77

Oxxygirl- Thanks...I would love to tell them what to do but unfortunately the technician has to follow what Mazda wants him to do in regards to this situation and they told him to order an engine. He's not going to get paid for doing any other work at this point.

shaunv74- Usually the power loss is higher up in the rpm and under load with a clogged cat....although you never know, cars can act very differently sometimes. I am experiencing a power loss from almost idle with no load but at 5k it wakens back up and I have full power.

Not sure if you have ever been in a car that you can adjust the igntion advance on....but basically it feels as though the ignition timing is being pulled until 5k. This is no matter if the car is hot or cold.

~0zzygirl~

Yeah, I hear ya... I just hope they checked injectors, valves, etc. That would be so much simpler. Good luck.

shaunv74

Your issue sounds different than the OP. I was thinking the cat. could be his problem.

kristopher_d

No power down low, in both cases sounds like APVs stuck open. That'll be 2¢ each please. Moon Buggy, I'll except €0.01

nmarz77

I should add that between 4k and 5k it felt as though it was breaking up and by 5k it ran fine.

I got a call from the service writer and the reman engine came in today. The tech is in the process of doing the engine swap so I should know more hopefully late tomorrow or Friday. I'll be surprised if it fixes the problem, but with cars you never know.

Moon Buggy

Okay guys... we got it.

I'll make the in-between story short (had to call MAZDA Europe to get help of engineer - finally head mechanics happened to be smarter and more determined to find solution and he got it - thumbs up to you, my friend!) : problem source : PCM communication problem with one of the 6 injectors. That was the cause of the lack of power.

The error codes we were getting was because the change of engine (new) + PCM (new) required a complete manual reprogramming of the new PCM.

Other problem isolated : an electro-valve was broken (the one sending more air in exhaust to boost burning at engine start - anti-pollution process). That one was complicated to identify but we got it.

Other information discovered (maybe you guys know that I haven't read enough on the forum, but I share info anyway). Apparently MAZDA Japan has extended the warranty of engine up to 5 years (instead of 4, here in Europe). Reason given is that there was an initial problem of the PCM instruction to send lubricant (oil) into engine. PCM was not sending enough oil, with as result the progressive destruction of the engine. They changed that later (reprogrammation of PCM), but decided to extend the engine replacement program (probably the reason why they don't hesitate much before replacing engines).

Also... I immediately noticed the start of the engine was nothing like ever experienced on my car. Immediate response as compared to long (yes, somehow cranking) start. Explanation : MAZDA also adapted their latest starters to rev the engine faster for a better start (that was before the PCM re-programmations, I guess). And man, the difference is obvious, compared to the starts I used to get before.

A lot of learning through this long process. At the end of the day I'm pleased to have my car back, running fine, together with a few things that might help around here. Then, as a final word, and even if he does not read this, I am thankful for the help I got from the head mechanics at the garage. The guy invested a lot of extra-hours into finding a solution and most important : understanding a problem solving process all by himself. He didn't get the necessary support from the so-called MAZDA Europe specialists and THAT is a shame, really.

Did you guys ever hear about similar problem? Like the mechanics who have to work on RX8 left alone without technical support?

@nmarz77 : good luck on your side... let us know how it goes after engine replacement.

nmarz77

Sounds like you are lucky and have a really good shop to bring your car to.

I used to be a mechanic at the worlds largest Porsche dealership in South Florida. We had so many cars coming through the dealer for service that we had to figure out and solve all the the new bugs and problems on most of the cars ourselves and then we would report them to Porsche Cars North America. A week or two later a TSB would be out. My dealer paid techs countless hours out of thier own pocket that they didn't have to so we could figure out the problems on the cars to get the car back to the customer and keep them happy. I once spent 80 hours tearing the entire interior, dash and trunk out of a Boxster so I could inspect for chaffing and test each wire of the main wiring harness to figure out an ABS issue which turned out to be a pin in a spot that it shouldn't have been due to a wireing harness installed in the car by Porsche that was 1 model year off. Spent another 20 hours converting an A/C system from manual to automatic climate control because of a misprint on the sales brochure.

I guess I expect every dealer and manufacturer to be the same way, but unfortunately it isn't so. You lucked out. I just hope the dealer I took mine to is just as accomidating as yours was.

Moon Buggy

@nmarz77 : Thanks for your note. I still haven't received the bill for this though, but I'm sure they won't charge me for the hours spent finding the solution.
And that is indeed very nice.

This said, I just think it is unfair for the mechanics who really love their jobs and are good at it. Unfair not to be backed-up by team and engineer knowledge center. MAZDA as a brand should be scouting these star-people and either reward them or let them become specialists who "share" their knowledge through the network, the other way around. This is IMHO the way a car brand can grow, through building stronger dealer network and happy customers word-of-mouth. Woops... couldn't help letting the marketeer-in-me shout here!

This said, nmarz77, I wish you luck on your side too.

PS : Driving my car this morning brought me up to a satisfaction level never encountered before (even when it was brand new). This new & reviewed engine really rocks!