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-   -   Weird Idle, No Misfire Code Anymore, I'm lost (https://www.rx8club.com/new-member-forum-197/weird-idle-no-misfire-code-anymore-im-lost-265158/)

Tristan Inman 05-01-2017 08:35 AM

Weird Idle, No Misfire Code Anymore, I'm lost
 
Hey all! I just recently started fixing up my RX8 and I've run into a little bit of confusion! I have read all the forums for issues and tried a few things but I thought I'd post my specific situation because I am driving a kind of unique RX8. So time for the whole backstory and all this stuff.

It is turbocharged with the Greddy Kit, has an emanage blue for fuel management, and that's really the only things that apply to this situation but If you need to know anything else then let me know.

I obtained the Pepsi RX-8 and it ran fine except for a CEL for no catalytic converter and it did have a weird thing where at WOT and shifting gears the car would stall out and stop running, I assumed that the emanage blue was the culprit and was trying to make time to tune it so I left it in the shop for some time and only drove it for maybe 15 miles. After it being parked it started to backfire when letting off the throttle but staying in gear at maybe 2-5k RPM*. But it still ran fine so I parked it again and next time I went to move it so I could work on my other garage queen, it was really hard to start up, granted I do have the crappy OEM 04 starter but it was harder than usual and also idled poorly and threw a misfire code in cylinder 1 (I am aware that I don't have cylinders so calm down) and it threw the code for the P2004 for APV being stuck open. So because it just hit 16k on the odometer I decided to upgrade the ignition system and the new coils are installed and now it starts better and has no misfire but it is running extremely weird still. The ignition system is entirely new, coils are tested good, changed the wires and they all have spark to a ground and then put the new NGK Iridium trailing and leading spark plugs in and they tested good and everything is starting normally but not running normally. So now when I get into the car it starts, while staying in neutral and parked, but it idles for rough and if I go full throttle it will stall out but if I go half throttle it will drop and then if I gradually go to WOT it will make it all the way to redline and then when I let off of throttle it will backfire quite loudly. I have data logs of Idle with various OBD sensors and a video of the idle so you can actually hear it on. I'll post links to the data logs on drive and yeah any help would be appreciated.

* The video was taken with the only the downpipe to go ahead and eliminate clogged cat so no one says it. Either way the exhaust is only manifold to turbo to downpipe to muffler to atmosphere.

Everything is in that file and titled appropriately

https://drive.google.com/open?id=0B3...UtmczdhZ0tpa0k

Loki 05-01-2017 10:12 AM

So is the APV still stuck open?
Because you're pulling 12-16 g/sec of air at idle, which is high. Nominal is 5-7g/sec. So either the MAF calibration is wrong or it's really pulling more air somehow. Is this engine ported?

Tristan Inman 05-01-2017 10:39 AM


Originally Posted by Loki (Post 4816950)
So is the APV still stuck open?
Because you're pulling 12-16 g/sec of air at idle, which is high. Nominal is 5-7g/sec. So either the MAF calibration is wrong or it's really pulling more air somehow. Is this engine ported?

i haven't had time to the APV troubleshooting outlined by someone else on this forum and I've been thinking about getting to it after finals (last one is friday) but could that really be causing such a drastic increase in air?

Loki 05-01-2017 11:16 AM


Originally Posted by Tristan Inman (Post 4816954)
i haven't had time to the APV troubleshooting outlined by someone else on this forum and I've been thinking about getting to it after finals (last one is friday) but could that really be causing such a drastic increase in air?

It will mess with your idle for sure. I can't quantify it, but people who have stuck APV problems, have similar idle problems. The high air intake could be caused by the computer trying to compensate for the suddenly open secondary intake paths.

dannobre 05-01-2017 12:10 PM


Originally Posted by Tristan Inman (Post 4816954)
i haven't had time to the APV troubleshooting outlined by someone else on this forum and I've been thinking about getting to it after finals (last one is friday) but could that really be causing such a drastic increase in air?

Trying to tune with the eManage is very poor. There is no way to effectively use it for a tune that isn't plagued with errors from the ECU trying to trim out the results.

Pick a flash tuner or a standalone to get a tune that will work.

Tristan Inman 05-01-2017 12:59 PM


Originally Posted by Loki (Post 4816971)
It will mess with your idle for sure. I can't quantify it, but people who have stuck APV problems, have similar idle problems. The high air intake could be caused by the computer trying to compensate for the suddenly open secondary intake paths.

Okay I'll take a look at that hopefully within the next couple of days.

Tristan Inman 05-01-2017 01:02 PM


Originally Posted by dannobre (Post 4816982)
Trying to tune with the eManage is very poor. There is no way to effectively use it for a tune that isn't plagued with errors from the ECU trying to trim out the results.

Pick a flash tuner or a standalone to get a tune that will work.

Yeah I plan on getting a standalone AEM Infinity it's just hard to justify $1500 when I'm in college haha. Another thing Is that it worked for 16,000 Miles before this issue happened and it's just weird but yeah I hate this emanage.

CelestialGryphon 05-01-2017 01:23 PM

Brother builds race cars for a living. Won't use anything but the AEM Infinity suite for anything. Current car is a nonsensicle RB30 build. Adaptronic is best for this application.

Loki 05-01-2017 02:03 PM

If you have time and desire to DIY tune, to save money, look up MazdaEdit. You can sell the blue after to pay for it ;)


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