Anyone ever had problems with fuel pressure damper?
 

Anyone ever had issues with fuel pressure damper? If so, what were the symptoms? If it were to fail what would I experience ?

I'm currently.dealing with random misfires, misfires on 1 and 2, gas in my oil and HIGHLY erratic fuel trims. I have done EVERYTHING. It's a fresh rebuild, new bhr coils , plugs and wires, I've removed the intake to check for cracks, smoke test, swapped the throttle body just to see, new maf, had injectors sent off for reman, new NGK O2 sensor, I have midpipe, airpump delete, and ditched the CAI for stock airbox. I am out of ideas and running out of money.

Never seen that give trouble, it's just to take out pressure spikes so I'd imagine if it stuck the symptoms would be very mild. Nothing like what you describe.

Are the misfires at idle? At speed? Full or partial throttle?
What are your fuel trims on a warm idle?
Possible the injectors are. miswired? Very common to mix up connectors when installing the engine.
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Wow, that sounds like you've really been at it!

The pulsation dampener just smooths out pulses from the fuel pump and injectors opening/closing to help keep pressure consistent. I really doubt it would be a problem, it's a very simple device.

Hate to ask but have you done a compression test? Having a stuck side seal or something can do some really weird stuff. Worth knowing for 100% that the engine is solid and making good compression before continuing troubleshooting.

+1 on checking injector wiring, this can really do weird stuff.

Dale

https://cimg0.ibsrv.net/gimg/www.rx8...a8f22bffd3.jpg
What do y'all make of this ?

Can you do the same at idle? logs while driving are very noisy.
The -10 LTFT is a little weird but no tragic. It should run.
What's the AFR? It's trimming fuel back because it thinks you have too much, based on front O2 sensor reading.

Do you have the right injectors connected to the right places? Easy to mix that up and put secondaries in place of primaries or reverse the connectors and get results like this.

How would I know if the injectors are connected correctly? The car ran REALLY good at one point. Now it runs, but misfires like crazy and just isnt fast...at all. I connected the injectors EXACTLY as they were before. I labeled everything clearly. Not that I'm incapable of making mistakes, but just to satisfy my curiosity, is there anything else other than miswired injectors that would cause this ?

....and yes Loki, I will get a reading at idle with the pid's you requested. Thanks EVERYONE for your help !!!

This has a few minutes of just sitting at idle. Then I go for a drive ... The car only misfired once about 5 minutes into the drive after a redline and while putting my foot in it. The car had a surging idle and a sputtery acceleration. It had it's moment when it seemed to snap out of it and it wanted to pull hard and smooth for a brief moment, but quickly went back to erratic operation.

...also, fuel injectors are all wired correctly. I checked the colors of the wires and according to a schematic drawing I found online they're all where they should be.

Hmmm, this is pretty weird.
Your MAF is reading high (7g/sec at 800rpm is about 2 g/sec too much). You said the MAF was replaced, have you tried the old one again?
Does the stock intake or whatever intake you have on now have the intake wire mesh screens in front of the MAF?

Yes, I've tried both MAF's and cleaned them both with CRC Mass Airflow Sensor cleaner....no, there's no wire mesh. My intake is stock.
What's so strange is that the car wasnt always like this...Here's a file from March

Ok well you need those screens for a stable MAF reading. They straighten the airflow. For the moment that's all that comes to mind for why the MAF would read high/erratic.

Sorry, here's the file from May (not March). Had the same MAF set up. I'll see if I can locate a MAF housing with screens, but the only other stock intake I have to reference also does not have screens. Thanks for all your time and input. I will update this post as I move forward . Thanks again!

Yes, I found the mesh screen... It is actually inside the airbox.

Ok, let's put a bow on this one.... Instead of trying to go off what I could see with a flashlight, I decided to remove the UIM again and examine my fuel injector wiring carefully and use the correct reference I found online. All of my primaries were wired wrong. Both secondary injectors were wired correct and those were the ones I could see with a flashlight so I assumed that if the secondary injectors were wired right then of course he must've had the others right.... Well, we all know what happens when we assume.
So gentlemen, you nailed it from the start. My sincerest apologies for taking a shortcut and keeping you all involved longer than neccessary. I do appreciate your time and your great wisdom. Thanks to all of you !

you should run another log, also get a vacuum reading, both at warmed up idle, if you can.

think I saw something else, but not sure

Team,
You're dead on too.... While my idel smoothed out and the constant misfires went away, I am still waaaaay slower than I was 6 months ago. Something still isn't right. I'll run a log of my drive home today and then I'll do a cold start to operating temp at idel in the morning.
So what were you thinking you saw ? Vacuum leak ? If so, where could it possibly be coming from ? I've went over EVERYTHING under the hood probably 5 times looking for a vacuum leak.

https://cimg6.ibsrv.net/gimg/www.rx8...335738a03b.jpg
Couldnt get the file to load so I did a screen grab of the fuel trims, MAF, RPMs.

Had an odd code come up....U1900 CanBus communication.... What does this mean ? Not a whole of info online about that one.

Vacuum is between 13.1 and 14.2 at warm idle.

You need to pull the vacuum hose from the intake before the throttle body to the Jet Air Mix nozzle and completely block both sides. Otherwise it’s bleeding air into the intake for that purpose, which masks the true vacuum condition of the engine. It also bleeds air to the oil injection nozzles from before the throttle body, but I’m reluctant to suggest blocking that line too since some people might kill their engine if they mishandle it somehow. These are “good” vacuum leaks designed in the system from air measured by the MAF. Not to be confused by “bad” vacuum leaks not measured by the MAF. They do result in a Renesis engine appearing to have a low vacuum level compared to other engines though.

In the previous comment it seemed like there might be a vacuum leak. I couldn’t really discern anything from that log when I looked it a while back. I addition to rpm seeming to surge every so often, some of the data column titles are not easily understood, at least not in a quick glance. Perhaps American english is not your primary first language? You might also consider omitting data not needed trying to assess a vacuum leak, but in all fairness I didn’t indicate that’s what I was after. In general, when trying to assess a problem eliminating unneeded data (clutter) helps to see things more clearly. At least for me. I do appreciate seeing the data on a spreadsheet rather than graphed though. Thanks for that.

You also need to be concerned for certain check valves and vacuum in the intake valve/solenoid storage tank. If it’s not receiving vacuum or holding vacuum (check valve between solenoid tank and intake nozzle) then the SSV and VDI intake valves won’t function properly, leading to power issues. The wiring into the solenoid connectors is known to be come brittle and break with age, which then the solenoids won’t function properly for the valves, but generally this will result in a cel. Or also the solenoids themselves can go bad or leak, or their seal at the vacuum tank leak. All these things can affect the valves operating and cause low power. Also the electrical actuator and proper (non-sticking) function of the APV valve if it’s a 6-port. All these valves have to move freely and properly for the engine to operate at maximum potential.
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English is my first and only language lol, but I totally see where you'd think that. Those headers are just what the app puts up there. I'll weed out all the extra pid's and run another one. I'm thinking rpm, stft, Lyft, maf and I'll see if that app has one for vacuum. I actually used the torque app to get the vacuum reading and the Fusion app to get the spread sheet. Anyway....

I plugged the hoses and intake and my vacuum went up to fluctuafing between 14.2 and 16 at warm idle. What's odd is that when I drove it, it would dip down to between 3 and low as zero when I first take off and while accelerating it stayed down lower than warm idle levels. When I let off the gas it shoots up to the 20's and then back down. I also just noticed I have a coolant leak at the radiator nipple....so I guess I'm ordering a radiator today.

Let me ask you this.... Do you think this is something a shop could find with a smoke test ? I just had that darn intake off when doing my injectors and I went over it with a fine tooth comb looking for cracks or leaks. I'm just wondering what the easiest way to get to the bottom of this would be.

Thanks again for your time. I appreciate EVERYONE'S time and help, but when someone with your reputation chimes in it justimakes me feel better ... I have no rotary shops in 4 hours of me or Mazda dealers other than one dealer that has a bad reputation to say the least. So you guys are all I have. Anyway, I really REALLY appreciate your help.

***UPDATE****
I had an issue with the accelerator pedal . It just went out....literally wouldnt do ANYTHING. Car was running, but nomatter how long or hard I laid on the pedal the rpms wouldn't move. So I unplugged it and swapped it with a known working pedal. The car ran like it use to .... it just came back into form and it was GRRREAT....for all of about 5 minutes and then it went back to the same loss of power garbage I'd been dealing with. The following day that accelerator pedal just quit working completely like the other one. So I put the old one back ok...i n and it worked, but that same lack of power was there. So I messaged Charles from BHR (He's helped me out A LOT with this particular car) and he had the idea that there could be something glitchy with the pcm and suggested I have it reflashed. So I took it to the only dealership in a 2 hour radius and $200 later and all seems well. My warm idle vacuum even went from where it was around 12-13 inches to 16-18 inches. I don't know how or why, but after the reflash the car is running VERY noticeably better.