Done :wavey:

:drama:

Nitrodann finally went full retard:laugh:

no bro, your turbo plumbs directly into your crankcase which is sealed completely to allow pressure to build up and it actually pumps it's own oil through the return line. that's how awesome turbos are.

Well that's that. Since this is related to the reliability of the car I'll post it here and not in another thread. The car was driving fine till yesterday then once after going into boost the car is behaving erratically. Now every time the car hits boost is definitely leaner than before and I get a flutter sound similar to the hard spark/fuel cut and my AFR go a bit crazy. Also the car leans out bad once it's been driven.

???

Post log.

Happens right at this point because that's when I let go of the throttle. Which I just noticed reads 72 percent when in reality was WOT.

https://www.miataturbo.net/attachmen...ine=1369062980

The actual log would have a lot more information than a screen shot. Can't really help you much with the limited information in the screen shot. It certainly doesn't seem like AFR's are going "crazy."

I would do a TPS calibration though. Are you saying you had it floored the whole time above and the TPS tapered off by itself? That would be strange, TPS's are usually pretty reliable.

Yeah stupid me. I had the car floored and the log registered the throttle at 72 percent. AFRs and timing seemed fine and it was running fine then this happened with nothing that I can think off that would cause this to happen. I was driving the car fine then when I turned it on again this issues were present.

log and tune are attached now

Well, I looked at the log. Honestly, I don't see much wrong there. I see AFR going up to about 12.5:1, but a bit of tuning would take care of that. I don't see AFRs going "crazy," and I don't see anything that would cause rough running.

???

At 15psi, you've got enough boost to blow out your spark unless you've got a smaller gap or have COPs or LS coils. Assume you've taken steps to prevent spark blowout?

BTW, if you are concerned about AFR's going to 20:1+ when you let off the throttle, that behavior is normal. It's called "overrun cutoff" and is designed to cut fuel when you coast in gear. There's a dialogue in MS where you can adjust it or turn it off.

I understand the overrun cut-off. Do you know how the car behaves when you have faulty spark wires? sounds like a subi and hesitates. Well that happens then goes away. Under boost right about 4k rpm it happens again under WOT then when I do partial throttle the car can sustain boost without an issues.

Then if I the car is warmed up, during cruising I get AFRs on the 17-18 which I've never see. The car cruised between 15.6 and 16 before. I don't get what could've caused this. The car drove fine since the leak was fixed then after one drive I felt some sort of misfire then all this started. I checked the engine bay and everything seems to be in place. :dunno: don't know what to do

How do your spark plugs look?

Remember that a misfire will cause a lean reading due to excess oxygen.

All vacuum lines/caps in place?

I'm still not seeing what you're talking about in your log. Do you think you captured it?

I took another log. In this one I barely went into boost at 120 kPa or so and my AFR were in the mid and high 12. I also tried to use VE live tuner and it would not add sufficient fuel to make up for the the lean spots. I did wash the engine bay using a hose, but I did put a plastic cover over the spark plugs.

Could there be any enrichment that should be turned off? even if that's the case it wouldn't explain why the car is running erratic from one moment to the next :facepalm:

Next time you take a log and it starts having problems hit the "spacebar" on your keyboard and it will mark the spot in the log. This way we can easily find where you are having issues.

The TPS numbers are not a percentage but rather just numbers. Closed might be 32 and wide open might be 143. You won't know until you do a calibration.

I pulled the spark plugs to see what they looked like and this is what I got. There was some water drops on cylinder 3 ... maybe that's what caused the issues

IMG_1473_zps25295494.jpg Photo by superbuffon01 | Photobucket

I didn't know that. I just took the car for a drive to vatozone. On the way over there I had the issue happening to me. When I got back I made sure that the timing was correct and I did a log. I was able to do an almost full 3rd gear pull and a bit of 4th. There was just one lean spot that's clearly evident in the log.

TPS is now calibrated 0 = closed and 100 = open

???

In my Megalogviewer plots, the value is being converted from ADC to %.

Water and ignition components = BAD. Make sure you're using dielectric grease on the boots.

Caught it. I circled a couple of events from those pulls below in blue.

https://www.miataturbo.net/attachmen...1&d=1369162708

The lean event in the 3rd gear pull is clearly linked to a drop in the "RPM/100" signal. I identified another drop in the "RPM" signal during your 4th gear pull which also resulted in a lean spike. Note that these parameters ("RPM," "RPM/100," "PW," and "DutyCycle1") are not all logged at the same time. That's why the drop in the 3rd gear pull only shows in the "RPM/100" line, while the drop in the 4th gear pull only shows in the "RPM" line. In reality, they're happening in all of the parameters as reflected by the AFR.

Sooooooo . . . looks like you may have an issue with the CAS. I'd be looking at the wiring/grounding/water. If there's nothing obvious there, you may need a new CAS.

Ah, I wasn't referring to MLV but to the values you see in TS when you calibrate it.

Gotcha.

Thanks for the tips it could've been that the connection was wet. I drove the car again and it was fine. I'll inspect the CAS and make sure that is dry because this did not happen once before. I doubt I have to replace it. Thanks for the help :wavey: