Have you confirmed good fuel flow and pressure at spec.

How did you confirm the CAM sensor as good ? Use a scope ?

 

Fuel flow is a observable guess but pressure is good.
Yes, used a scope.
My assumption is that the engine convulsions are causing the computer to "see" the cam pos sensor out of sync with the crank?
Not sure, just a guess.

 

Fuel flow is a observable guess but pressure is good.
Yes, used a scope.
My assumption is that the engine convulsions are causing the computer to "see" the cam pos sensor out of sync with the crank?
Not sure, just a guess.

As you have a scope record the CAM/Crank correlation and post the wave form

 

It's not mine, I will reach back it to my buddy and see what we can do.

 

I will scope tomorrow, and post the findings.
Doesn't the computer compare cam and crank live as part of the information gathering? It seems that is critical information that would always be used....

 

cam sensor failing is common on these. mine went at 162k. it can be done with out hardly any disassembly. the crank sensor is the real bitch. if replacing go oem. the part is like 30$ on ebay

 

Ok checked both cam and crank sensors today. Both good. Took a video.
Can on top and crank on bottom.

 

Ok, that is the picture of it. I can't upload a video? Mp4 not an allowed extension

 

Now can you find a wave form of a known good to compare the correlation..

 

Help me understand?
The wave form was showing proper expressed value with crisp, and correct form. If the ground was bad it would have been messed up. Both positive value, and signal values were in great form.
Crank signal duration is consistent and properly scaled.
Cam signal was properly scaled to the crank signal with a correct set point (the longer wave).
What would you be comparing?

 

You also asked for fuel trims. Here they are.

 

Although you have a Cam/Crank wave form, it is now important to ensure the the triggers are happening at the correct time in relation to each other and TDC.. I know. confusing !!

The fuel trims are reporting a very lean mixture.. the ST and LT must be combined to arrive at the proper adjusted amount. At this juncture the Cam/crank correlation must be confirmed before worrying about the Trims. For future refence, closer to "0" is desirable..

 

Not confusing, I understand that would be optimal. I truly appreciate the "Test, not guess".

Common sense tells us that the ECU controls timing off of this information as well as cam phasing, if it was not at synced TDC, it would run rough and throw a code as well.
This engine has run super smooth and good power when it's not "missing" which indicates it is correctly timed.
It's not just a guess, it is an observed truth.
Now that does not mean that something in the VVT is not going out of phase when the "miss" occurs, however I am unable to measure the wave form at the time of event, only because it isn't practical to do so while driving down the road. Lol.
When it idles, everything seems to be fine.
If i go for a drive, and it starts "missing" i can shut it down and a restart usually causes the problem to go away for a while although that is not guaranteed.
I went through the various grounds as well last night. Everything was solid, next I'll be testing ground at ECU.

 

Is there a good way to static test the VVT, to verify it is working correctly?
Is it a hydraulic actuator controlled electrically or mechanical, or?

 

The purpose of the record function is that the scanner records for later digestion, you do not physically monitor while operating the vehicle..

The session is recorded and saved to a file which can be opened and run at a convenient time..

 

I have recorded the scanner with markers for events. I can see the rpm drop, as well as jumping in and out of open / closed loop when the event occurs. Nothing else really changes (outside of the obvious association with rpm drop. I.e. load%)
I don't know how I could show you any of this without video upload.
Anything in particular you think I should focus on?

 

Nothing new to report, I have monitored with scanner and can't find anything.
I did find it that kia / hyundai both use "slow" computer data reading and response... it could have a major failure and not even catch it, only see the after effects.
I have taken it to a dealer...
They can't figure it out either, 2 weeks now with no progress but lots of head scratching...

 

Can your mechanic record the DATA on a SCOPE ?

Using a scanner, especially if not a top tier will not be able to catch the DATA, also the more PIDs displayed will reduce the speed... If not this is beyond his pay scale...

You will need to locate a diagnostician, not a mechanic...

 

Just a note. The fuel injector harness clips get very brittle. It doesn't take much to cause them to get loose and cause a misfire. I had to replace one at the second TB change after chasing a #5 misfire. If you are in contact with the mechanic run that by them if they have the top off again.