Hi Folks,

after my workshop finally gave up I would like to post my troubles here hoping is there's somebody out there helping me getting my red one back on track.

First a little bit history:

In May 2009 i found a Nov. '05 with 76000 km on the clock for a reasonable price on the used car market in Shanghai. On test drive the only trouble it showed up was a broken wheel bearing, not a big issue since mazda is using standard bearings for 50 bucks. So I made it mine. Shortly after purchase the "Akropolis" issue came up (cooling water level low). Found a connector on the cooler broken due to material aging - very disappointing. Nevertheless the engine never run hot, I changed the radiator immediately.
One week later - warm start problems. Checked the PCM SW version - OK, so changed the spark plugs. No improvement, there for the engine came up with more and more rough idle and finally knocking @ 6000 - 7000 rpm.
At this point I should mention that my workshop is certified for the RX-8, but the guys there are not the smartest. Unfortunately in my small 5 mio people town there is only one RX-8 shop because there are only 3 rotaries running (!). So I found a copy of the workshop manual on the www and after 2 days fighting I convinced the workshop to go through the "knocking/pinging/detonation" troubleshooting procedure. Found low compression, kick or overhaul the engine . Ignition, oil metering system, fuel pressure pump and fuel pressure regulator showed normal behavior. First I was thinking about overhauling the engine, but mazda blocked the spare parts for the RX-8's heart here in China. If you want to buy rotor seals, you have to apply for release, wait for Japan to confirm and then import the parts. Takes around 3 months. Forget it, order a brand new engine for 9000 US$ (yeah imported goods are luxury in China due to customs and tax).
I still need to find the root cause for the failure of the old engine by taking it apart, but first I should get the new one working... The "specialist" blames that on the bad fuel quality, I should fill 97 instead of 93. I guess he gets his cigarettes for free from SINOPEC. Honestly, I wouldn't fake the low grade fuel by taking high grade and stretching it, rather I would fake the expensive one...
When swapping the parts from the old engine to the new one, I found that the whole air intake system was so dirty, the built-in flaps were stuck and could not even be moved by hand and a lot of force. Have a look:

Everything was cleaned, engine was assembled and implanted into my red colored tin box. This still happened last Saturday, unfortunately I got sick on Sunday and couldn't join the final assembly and the tune-up. According to the mazda guys everything went smooth and I went there to pick up the car on Monday morning. But there came the no-go, the engine was stalling at idle. So I left the car there and went to work. They were searching (according to check-list, but I don't really believe them) until Tuesday evening when they finally gave up and I took the car back.

Now I'm on my own with 9k drained from my bank account and a car that still behaves like a girl. Today morning I was driving it to work (50 km) and monitored the behavior:

- At cold start the engine is running on 2000 rpm for a while before lowering.
- After 30 sec it starts to swing between 750 and 1500 rpm, very rough at the lower end.
- The swinging window is getting smaller and smaller, suddenly the engine stalls.
- After 10 min in city traffic, the idle is stable @ 850 rpm.
- Driving at constant speed and rpm for a while and releasing the clutch then causes unstable idle again and sometimes stalling, even after 50 km.
- When pushing the throttle during unstable idle, the power comes with a delay, but with some kind of punch.
- The power output seems to be lower than before with the blown engine, but this could be a subjective impression because I don't rev it over 5000 right now and the engine sound is much more smooth than before.

According to mazda everything was checked, nothing abnormal was found. What I can confirm:
- No DTCs displayed
- fuel pressure OK
- injectors cleaned (2 times) and new seals
- ECT signal normal
- IAT signal normal
- ignition normal (no sparks, timing OK)
- APV operating normal
- purge valve operating normal
- secondary air injector pump operating normal

Please feel free to give me any hint what comes up in your minds, I will drink a barrel of finest Weihenstephaner Hefeweizen on the poster who can help me out of this disaster

Greetz
Mike from China

Edit: feel free to keep any spelling mistake you may find...

 

I too have encountered the dreaded stuck SSV while working on another RX8.
I assume you cleaned the valve before installing it (I use carb cleaner).
Did you also clean the inside of the SSV housing?

I also noticed that the SSV gasket wasn't in the pic.
Are you missing it or did you just remove it before taking the pic?

 

Yeah the housing was cleaned and the gasket was replaced by a new one... Don't have a pic from the housing, but now it looks same like:

 

The symptoms you described in the first post is so similar to what I encountered with the stuck SSV its not even funny.
Have you checked the SSV (installed in the manifold) to see if it opens without resistance and then returns to the closed position on its own?
Also, put a vacuum pump on the SSV actuator and see if the valve opens and closes smoothly.

Other things to consider...
When you replaced the engine did you also replace the ignition coils and wires?
Do you have a good battery and have you verified the connections at the battery are secured/tight?

 

I tested the SSV operation with a manual vacuum pump - OK

Battery connections are OK

Ignition coils and wires have not been replaced because they don't show any problem according to the workshop manual test procedure - anyways right now I just asked for a quotation and delivery time.

Somehow I believe in a problem with the injectors - when I rev up from unstable idle the throttle actuator responds immediately but the engine gives a "starving" sound. Might be possible that their universal engine cleaner made more damage on them than cleaning...

 

You're not getting any CEL codes?

 

nope

 

Just to rule out the ignition circuit, I would install an inline timing light onto each plug wire and see if one of the sparks/lights appear weak/inconsistent.

 

If ignition spark tests OK, do you think it might be one of the other scenarios around a major change-out in the motor or control systems associated with the motor?

https://www.rx8club.com/showthread.p...ight=pcm+reset

Possibly the original motor mounts were bad and they were reused or they were improperly installed with the new motor (should be some other tell-tales that go along with this one though)?

Bad neutral switch (I'm reaching here)?

 

Ok, yesterday evening I had 6 of my engineers off their work and searching for an inline timing light... guess the result? "In China don't have!" Because motos are very rare here, I couldn't even find those fancy plugs with built-in light I use on my Guzzi in Austria ^^

So I did it the only way I could do it - pull my favorite fuse F20, take out the spark plugs and visually check the sparks while cranking the engine. Actually I like this method because I'm used to do that on my oldies since I got my first 50cc..... OK that's another story. Sparks are bright and equal on all plugs.

Neutral switch N/A -> MT but I remember to have read something about a load switch, could it be that one?

From now I would consider the ignition system ruled out. Also the symptoms do rather point into the direction of air intake / fuel injection. I have to look after something which is physically changing with the engine temperature (no PCM output, the ECT shows operating temperature and the problem still persists). What could that be?

Today morning the car gave me another hint: at cool engine I noticed a short power loss @ exactely 4500 rpm, throttle position has no influence. So does anybody have an idea what exactly the PCM is doing at 4500 - maybe I should have a closer look at the effected components.

Greetz

 

It sounds to me like you have a vacuum leak somewhere in the intake manifold that is allowing unmetered air into the engine. Double check all your gaskets that you replaced. You can also wave an unlit propane torch around the gaskets while the engine is running. Any spot where the engine speeds up or slows down when you wave the torch around it indicates a leak.

 

Hi folks,

after a week of troubleshooting i found the problem. The stupid guys changed the wires for the fuel injectors - FP1 and RP1 were connected to FP2 and RP2...

Got the idea to check that after reading through the injector topics around here. Thank you all guys, I'll have my barrel of beer on all of you

Greetz
Mike