Tacoma - OVTUNE - VFTUNER - Update Info and Original Development

When I did this they could not find anything wrong with it. My truck is smooth with the factory tune. I'm not opposed to changing the sensor myself, I just want to make sure this is the actual issue before doing so.

 

Going through the service department right now and I read the same thing. The stutter I agree is not part of the tune. I think it has to do with the crank sensor being replaced.

 

My truck did not do it before the tune and didn't do it with the tune until I installed the Spec U exhaust. I want @OVTune to see logs before I jump to conclusions.

 

Something interesting to note, I cleaned my MAF when I got home tonight. I haven't gone out for drive, but I did start the truck after reinstalling the sensor and letting it dry. I noticed on my way home that on my truck the fluttering happens almost exactly at 1800 rpm +/- maybe 150rpm. With the truck stopped in the driveway and gently revving the engine I can feel it stumble at that exact point. I am looking into techstream right now to see if I can log anything.

 

Quick followup before I start dinner. You can absolutely log just about anything in techstream. You can save the data in toyota's proprietary format, or export it to a .CSV.

I did not have time to go out for a drive, but I will take a log on my commute tomorrow morning. The attached .csv is a log from my truck sitting in the driveway reved up to the ~1750 rpm where I can detect the stumble. I didn't change any of the settings and it looks like it was updating about every 0.5s. I will see if I can analyze the data and infer anything from it. The stuttering is not nearly as noticeable as while driving.

 

My $.02, if you are custom tuning your truck and aren't on a recall list, replacing your CKP is a simple thing to do. Sure, try w/ the dealer but if they can't replicate the symptoms w/o your tune I really doubt you'll have much luck (I didn't). But replacing this part costs you $90 and takes 10 mins to swap (just do it after your truck has sat overnight so its cool)

 

Ignition looks to be all over the place, 20* 40* -2*

This is such a low rpm low load range I don't modify anything in this area of the tunes ignition

 

That seems like massive learned knock correction.

 

@OVTune what size micro SD card can we use for logging? Any special speed requirements?

 

@OVTune I've had the misfire/fluter since day 1 of owning the truck, it's most noticeable in the 1500-2200 RPM range when the motor starts loading up in 4th gear. Took the truck in today for the recall, service advisor didn't even know about the recall until he looked my truck up. Sensor was replaced and now the truck is smooth.

On a side note, while the truck was being serviced, I had them run me back to work in the Sieanna minivan. The minivan felt like a rocket compaired to the Tacoma. The guy was joking that it feels like it turbos under the hood. The sad part is the Tacoma has the same 2GR-FKS and weights 100 pounds less than the van. Any chance you can get into the ECUs on one of these vans to get more data for your tunes?

 

Here is what i logged with the torque app. I don't know how to use it so i don't know if it does any good.

 

What transmission does the van have?

 

You're looking at learned positive correction. Lower numbers are worse.

The ECU has multi-layer knock filtering.

first it has learned noise
then it has base filtering, then it has coarse adjusting, fine adjusting, final adjustment, learned multiplier.

The Knock learned value is the sum of total the ECU *may* remove from the knock correction Ignition map if it needs to.

Knock Learned * AM = End result ignition ADDITION to base.

The lower the learned knock advance, the worse the car is doing, generally. (although it depends where in the RPM range)

 

Has an 8 speed.

 

Whoa! Need to put that data in an Excel worksheet, that shit gave me a headache

 

What's your average MPG after tune and regear?

 

Read a Car & Driver article on the 'FKS equipped 296 HP '17 Sienna, they liked the powertrain and the thing hauls ass (for a van). Claimed 6.8 0-60 time. They did say the throttle is "lazy" though - that's familiar!

 

I will definitely log ALL engine data tomorrow, I just did the selected items to test it out this afternoon. Tomorrow morning I should have more useful data to share. I understand you don't change anything at that low RPM. Do those large swings in timing make you suspect the CPS still? The VVT is almost completely stable for the entire short log. It doesn't look like (with no load) the VVT is causing the issue as you had initially suggested.

 

That was my initial thought as I wasn't fully aware of the crank position sensor issue.

That ignition timing does not look normal. The ECU never wildly swings ignition like that. Ultimately Ignition is calculated by Crank Angle...so it is something to consider.

email me some full logs and if you can do wide open throttle as well

 

WOT with pleasure. I'm going to order the CPS tonight if I can find a source.