P0016 datalog assistence
 

Hey all,

I was wondering if you guys could help me out.

A while back I saw a thread posted about the P0016/P0017 CEL and it being potentially caused by a mechanical failure in the intake cam actuators.

http://www.ft86club.com/forums/showthread.php?t=67821

I have the classic issues of car stalling on deceleration occasionally, rough idle at times, and rpm dips too low after I blip the throttle or push the clutch in. I also had the P0016 code. I had my tuner remove it from my map and am just now getting around to figuring this out.

I recently created a log of my symptoms and I was hoping someone could take a second to take a look at it and tell me if my vvt intake angles look laggy or normal. To me, it doesn't seem like there is anything wrong with either intake angle. But I may be missing something.

In my log, I was stationary and simply blipped the throttle 5-6 times. You can see in the log that my RPM's dip very low after each blip. Also, my STFT goes far into the negative at the same time the rpm dip happens. You can also see the afr gets very rich when the RPM dip happens.

The previous owner posted about potentially replacing the bank 1 intake cam actuator (even posted a picture of the new part) but I am unable to tell if he actually followed through with installing it.

It very well could be the ECU itself has burned in the incorrect parameters, and I no longer have a hardware failure. Or, there is still a mechanical failure. Or it could be something else entirely.

http://www.datazap.me/u/blackfirebal...0&data=6-10-29

Thank you guys for your time.


EDIT:

I went ahead and zoomed in on a part of the log that I believe is really telling of some kind of problem.

There are 4 lime green markers marking the rpm dips that happen shortly after I blip the throttle.

http://www.datazap.me/u/blackfirebal...97-331-358-426

The actual afr is all over the place compared to the target afr.

Im having this exact same issue, minus the stalling since yesterday. I will go to check with my tuner on monday, most likely to disable the code first and see how the car runs afterwards. I will tell him to look at your logs, and to look at my data as well, to see if we can figure something out. Tag me on monday night if I havent come back for an update.

Thank you so much! I'll definitely do that.

Goodluck with your issue.

@Icecreamtruk I edited my original post with a highlighted section of the log that I think shows the symptoms of the problem a little better.

Your long term fuel trim is over -20% at low rpm, looks like you have a fueling problem

Caused by
Aftermarket intake
Bad maf scaling
Dirty or faulty maf
Intake or exhaust leaks
Faulty fuel injectors

Interesting.

I appreciate your response very much.

It's worth mentioning that I am boosted.

You believe this is a completely unrelated issue then to the P0016 code that I had removed from my tune? Also, do my intake cam angles look normal to you?

The car drives just fine and builds boost normally anything above idle/decelerating.

Haha yeah boosted makes a difference

Check your bov if its downstream of the maf sensor, few guys have had leaky bov so the maf is metering the air, then some leaks out of bov at idle, ecu fuels for total volume of air then has to remove a lot of fuel via negitive ltft as air has leaked out of bov. Thst can cause symptoms your seeing

Also check the gasket at maf sensor sometimes boosted guys get leak their as well or any inrakes leaks post maf

Sounds good! I will do that!

I took a visual look over my BOV and piping, as well as any visible vacuum lines.

Nothing looks to be a problem, but I might have to perform a leak test.

I made a thing today. lol.

https://lh3.googleusercontent.com/uX...g=w528-h872-no

https://lh3.googleusercontent.com/Do...Q=w527-h872-no

Update even tho your problem seems unrelated. Took the car to the tuner, he initially logged with a "standard" ECU reading tool, and everything seemed and looked fine, logs very similar to yours. So he erased them, went for a drive, and the code came back up. So he then pulled the laptop and started logging other things with Ecutek only to find out that even tho the ECU reports the cam angles to be more or less ok, they werent actually working at all. All cam sensors were reading 0 volts at all times. So he then went on a hunch and replaced the sensor on the right side, and boom, magically it works. Code doesnt come back, car has gained some power that probably lost over time as I didnt notice a power loss, but certainly noticed a power gain after it was fixed.

The whole "once the P0016 comes up the ECU seems to be done, even if you replace the parts it keeps coming" thing that I seem to read in several threads here is more than likely that the ECU was faulty but not all ECUs are at fault when this code comes up, at least mine wasnt.

Interesting. How did your tuner log the voltage to the sensors? Is that a parameter in Ecutek or did he manually check them with a volt meter?

Which cam did he end up replacing then? You said the right, but was that the passenger side top (intake bank 1 (that relates to the P0016))?

Thanks for looking into that and remembering to post back here. There's a small chance I could have more than one things going on. First and foremost I have to figure out my fueling issue. Just need to find the time to test for boost leaks.

He checked with a voltmeter for the electrical connection, which was fine. He then checked with Ecutek for something he wasnt logging before (techstream or some similar software he was using). With ecutek he was able to see the sensors all reading 0. It was indeed passenger side, I meant right as in, right when standing in front of the car and looking at it, so passenger side.

get maf cleaner and clean it. Start with cheap fixes.

I would totally start with cheap fixes, but this has nothing to do with the MAF sensor doesnt it? Its cam gear position related, so only the cam sensor, the cam sprocket or the ECU should be related. Oil might have something to do (since this all works based on oil pressure), but I dont see how AFR has anything to do with it.

Edit: unless you mean get MAF cleaner and use it on the cam sensor connection, then yeah, you could start there I guess (if it can be used that way, I dont know).

@steve99

I went ahead and tested for boost leaks. I found a handful of small leaks and addressed them.

Unfortunatly, it doesn't appear to have made a difference.

Updated log:

http://www.datazap.me/u/blackfirebal...ata=6-10-11-21

I'll get some maf cleaner and see if that helps.

Yeah still got high negitive ltft at low rom\ idle and it gets better as rpm and hence air flow increases and by 3000 it looks ok.

It posible its a maf sensor issue or leaking injector.

Do you have someone you could swap maf sensors with ?? As they are quote expensive to buy,

The other thing that looks rearly suspect is fhe manifold pressure it reading up to almost 1 bar pressure which is about 14 psi boost at 1500-2000 rpm seems increadably high.

I think it looks like you have a bad MAP sensor ie manifold pressure sensor, this could be effecting tune they are known to fail ight be worth seeing if you can swap in one for a test must be same one you have if its non standard

Im assuming this tune has run ok previously eith the current injectors and setup so we can rule out badly scaled port injectors, and your not running flex fuel kit.

Good video here on diagnosing issues with ltft

https://youtu.be/5WnM_NsOtd8

I have a boost gauge and it does not reflect 14 psi of boost at that rpm. I wonder what is causing that.

Would the EVAP hose under the Intake Manifold cause these symptoms if it popped off?

I was just doing some reading and this issue popped up in my searching. I had also remembered that a P0441 code was the other code I had my tuner remove from the tune to get the slip light to go away.

I'm going to check that as well.

Fun fact, I actually have another maf sensor I can test with. A while back, I thought I had a bad maf sensor so I bought one. Turns out one of the wires in the maf harness had come loose. I had a shop source me a new one and install it.

I wonder if something with the work that they did is actually not correct. Hm.

Or wait, is the maf sensor that is located post intercooler, but pre intake manifold different than the "map" sensor? I might be confusing the two.

Edit:

Oh I see now. Right. The mpa sensor is on the top right of the intake manifold.

Some extra info on my setup that may or may not be relevant:

I have a dual radium catch can setup.

The PCV can on the right, vents to atmosphere.

The crankcase can on the left has a check valve between the intake manifold and the catch can. Then it routes from the can to the crankcase.

I'm like 99% sure that the check valve is flowing the proper direction (intake manifold --> can --> crankcase) but playing devils advocate, if that check valve was on backwards, would it cause this problem?

Photo of catch can setup:

https://goo.gl/photos/jXFHFnYjeYezZ7Qg8

Im assuming the ecutek log is correct, the MAP (pressure) sensor is in BAR and it seems to be reading incorrect values

Hm. Ok. I will look into that.

So correct me if I am wrong. (I watched the video, knew about 75% of it, but it really clarified and solidified my understanding of fuel trims)

What is happening to my car is for an unknown reason, my car is running very rich, at idle, but not under throttle. This is why the ltft reads -22.7 under idle but bounces back to 0 under throttle. If the MAP sensor is reporting an artificially high number, the car would think it needs to add more fuel than is necessary to compensate. My car has learned this imbalance which is why it is showing up in the ltft. Does that sound correct?

yes thats correct, for some reason the ecu is needing to compensate for and overfueling (or perceived overfueling) situation and its doing this by using a large negative fuel trim.

This may or may not be related to the MAP (pressure) sensor which seems to be reading very high levels of boost pressure at low rpm.

Usually fueling problems are to do with injectors , mas air flow sensor MAF, or oxygen sensor or air oe exhaust leaks ect.


now as you boosted and using ecutek, its possible the tuner has used a custom map setup that ties manifold pressure to fueling OR you using a speed density tune which used intake air temps and manifold pressure to determine fueling. If you on a speed density tune them MAP reading will effect fueling a lot. Maybe talk to tuner

I can't view the logs but 1 bar MAP is 0 bar of boost, or atmospheric pressure. 2 bar MAP would be 1 bar of boost....

Poor idle is usually sorted by fueling correctly. Any changed injectors etc?

Hah yeah too late in the day forgot that for absolute manifold press vs boost :-)
Look like the map sensor is fine

Back to the cam code and fueling issue

Bosch 550cc injectors

Hm, gotcha. So when it is below 1 bar it's showing vacuum. Got it.

The longer I look at this and the more I read the more I think it could be a leaking injector. It is such a drastic amount of overfueling happening after throttle.

Look how even the stft has to drastically compensate for the excess fuel to maintain stoichometyry.

http://datazap.me/u/blackfireball5/l...5&mark=709-661
@steve99

What is "injection time direct final ms"? Can't seem to find any information on this parameter with Googling. There seems to be some kind of fluctuation happening during this rich event at the link above.

Thats the amount of time the direct injector is opening in milleseconds.

Unfortunatly with these cars being duel injection system makes things more conplex.

Their is tables in tune that determine the ratio of port and direct injection used at any given time based on load and rpm. Standard setting at or near idle is arroind 30% port and obviously 70% direct. To achieve the desired fuel delivery. However tuners often cgamge this ratio when using bigger injectors to rely more heavily on the port injection system. The pi di ratio also changes with load and rpm see table below, but tgis is stock tune, yours may be different

http://www.ft86club.com/forums/attac...1&d=1448324203

Gotcha, so is the fluctuation i'm seeing at that point relevant?

I wonder if the latencies are set correctly. There are settings for min DI and PI volumes, these also need to be corrected when changing injectors. If bigger injectors have been installed, usually the setup is the cause of poor idling and fueling error.

So, the car was professionally tuned by Pure Automotive under the previous owner.

I can confirm that the car used to run properly under this tune and settings at one point in time.

It still had the idle dip, but at least the ltft was properly at 0.

http://www.datazap.me/u/blackfirebal...data=5-9-10-19

This was from like, 2014.

Does anyone know what the ideal maf sensor voltage should be around idle? I notice that mine in my log is reading anywhere from 1 to 1.5 v at idle. This article I just read is stating, "The output signal is typically about 0.7 volts at idle and about 4.5 volts at wide-open throttle."

http://www.autoserviceprofessional.c...ow-sensor-lies

There's also a section in here that states, "Usually with a dirty MAF, long-term fuel trim will be negative at idle and become more positive as rpm (airflow) increases. But we just noted that a dirty MAF under-reports airflow; why is long-term fuel trim negative at idle? Actually, given enough time it might start to increase, but on most models it won’t change at idle as long as the short-term trim is able to keep total fuel trim below the code-set criteria (25%)."

I currently have my car at my shop. They discovered the bov was sticking and not moving very smoothly, so they serviced that.

They are testing now to see if that helped, but I am thinking if that does not help, the maf my be where I should look.

I know someone mentioned to clean the maf. I should have done that but I was wrapped up in looking for boost/vacuum leaks.

UPDATE:

So a long time ago, I had an issue where a wire going to my maf sensor was severed. I had that repaired by a shop years ago. After reviewing the log again and doing mroe reading, I suggested to the guys currently working through my issue to look into the maf sensor. They said that hey wiggled the plug to the maf sensor while the car was running and it died. They unwrapped the plug and two wires came out. The previous shop did a crappy job. The new plug was supposed to be here today.

Will update this thread if this solves my problem. Thanks for all the help everyone. :)