Mystery intermittent hesitation/stumble from a stop?

Today I pulled the plugs the passenger side looks normal the driver side looks a little rich. Cleaned the intake and MAF sensor with MAF sensor cleaner and let dry over night. Also cleaned my intake pre throttle and throttle body. Replaced the air filter then plugged in my reader and did a drive cycle. Now I'm getting a P0102 MAF code with now CEL. sensor still reading below the spec. I'm going to order one and replace it.

Yesterday I ran a can of seafoam through the intake and put injector clea er in the tank. After the road test with the sea foam it dose run a little better.

More to follow.

 

Did this WOrk?

 

Nope, brough it to the dealer didnt find anything wrong. Said it was the best running and looking 2nd gen they've ever seen.

 

you still have the CEL? and code P0102?

 

Your code is for low voltage at the MAF sensor.
I'd look for bad or loose connections between the ECM and the MAF.
If the connections are good, and wire integrity is good, replace the MAF.

To check wire integrity. you could monitor voltages on the scan tool as you wiggle wires. Key on. (if your scanner shows voltages)
Or use a voltage meter.

 

Never had an engine light only a permanate code.

 

My 2013 Off Road (67k mi) is having a similar set of symptoms!! Very similar.

I haven't looked at my injector volume lately, I'll check and get back with you.

I have the same unbalanced idle spark advance readings, I think even down to cyls 5-6 kind of breaking the pattern.

My fuel trims are something like B1S1 -1.5, B2S1 +3.2 at idle, and they still seem a little biased in the same direction under load.

My MAF reading is in spec.

First I'm going to ask you some questions, and then I'm going to tell you the facts about when my truck started acting like this.

1) How is your mileage? Does it seem to have decreased at all?

2) At idle, do you ever get a sort of a harmonic thrumming? Like when you have two very similar tones that are off by just a fraction of a phase and they periodically come into and go out of phase with each other?

3) Go back into your live data and come back with the values of "Engine Speed Fluctuation Avg (Worst value)" #1 - #6

4) Is your cold start idle noticeably worse on cold days (<60°) than on warm days (>70°)?

5) Do you ever hear a clunking noise like the one in this users video? https://youtu.be/uP71INwgcuk?si=yW8hLnN1luXtdD5I

NOTE: As the camera moves out the driver door at 00:06 the noise quickly becomes the dominant sound you hear (clunk-lunk-lunk-lunk...)

If you do, is that associated with ambient temp in any way?

OK now my story.

My truck has never had a single mechanical issue except one. Two years ago mice ate my knock sensor sub harness, the shop I went to for the repair (chosen because they said they could replace it without having to take the head off of bank one) were a bunch of fucking incompetents. The first thing I noticed was that they left the vacuum line for the fuel pressure regulator off of the air box. Since then I've discovered that they broke the bracket that holds the heater hoses behind the upper intake, they broke the filter off of the ACIS VSV, and, now we get to the meat, THEY CRUSHED THE HARNESS SIDE CONNECTOR FOR THE BANK 1 VVT SOLENOID.

I have since transplanted new plastic onto the factory harness as the internal pins were undamaged and able to be saved, but I worry that that solenoid may have been under-current at while that broken connector was still in place and suffered damage or degradation.

I think we both have VVT issues, just like OP.

I'll pull my actual numbers from my logged data later today and post an update. But your readings are so god damn the same as mine I feel like I'm looking in a mirror!

I'm really really glad I came across this post, even more so your comment. This is the first time I've seen someone else with concretely analogous behavior and live data to show for it.

Buddy, I'm kinda excited.

 

That sounds like you might just have not had the sensor fully plugged in while the key was on at some point

 

MY TRUCK did and does this a little still
i noticed an improvement with new air filter, maf cleaning, and TB cleaning a little (ironic)
2015 taco 4.0 90k miles

i never got a code by the way, just a slight choke off the line
the things i did above did improve it but sometimes i feel it still, my mpg improved, its pretty good

i wonder about that vvti solenoid thing though - but i dont want to mess with moving the alternator. i might just even run it and not worry about it too much

 

did you have to swing the alternator out of the way to access drivers side?

 

No, no, no. Whatever your thinking of...
Aha! You're thinking of the VVT OCV filter cover. Those are the big hex heads on the side of the head, the solenoid itself is on the inside ... side of the head

Wait one, photos incoming

 

Here, I've illustrated both OCVs and the bank 1 VVT sensor.

 

You would def have to move the alternator to get to the bank 2 VVT filter.

Did you watch the videos I linked in my earlier comment? Does your truck sound like that ever, how about when it's cold out?

 

thanks for those marked up photos above...
my truck has no cel, but it used to choke for a split second off the line,
then i did air filter (oem), TB cleaning (minorly) and cleaned MAF and it improved, as did my mpg
but i still get it sometimes. the video you posted, i cant say i hear that clunking...the engines are noisy to begin with haha

thinking maybe the vvt solenoid thing in future perhaps since it doesnt require moving alternator

i bookmarked a few things from this thread...at the same time, my truck doesnt run bad overall, im not overly concerned with it