Stumble misfire condition

A week or so ago I took my in truck yet again for the stuttering problem. Previously the Toyota regional service guy said it was operating as designed and that it would eventually learn how to not stutter. Well that was 1500 miles ago and if it hasnt learned by now its not going to. So on the latest visit they hooked up techstream and let me drive around for an hour to get a good log of the problem. I was able to reproduce the problem while it was being logged and took note of the times when it was really bad. I also sent them a video of my trucks tachometer when it did this.

Well I got the call from my service manager yesterday and he said the toyota regional guy agreed there was a problem and they are working on a firmware fix for it. And he would let me know when it was available. Hopefully this is something that will help all of us.

 

This sounds promising, thanks for sharing!

 

Manual or Auto? If this was previously mentioned, my apologies

 

Agree! Replacing that part shutter gone. I was on the recall list tho.

 

1st and maybe 2nd pulling onto a state highway I let it rev up to 3000 or 3500, but I shift around 2500 from 3rd, to 4th, and swap form 4th to 6th all the time. This sucker still pulls in 6th at ~1500 at 45 to 50mph no problem. It won't punch you into your seat, but the mph's rise up to 60+ no problem. Very smooth manual tranny, if not the smoothest I've owned besides a civic with 250,000mi. Enjoy your new truck!!

 

I will say, that even since my initial post, the truck does seem to be smoothing out a bit. It still has less than 150 miles on it but an heading out on 1000 mile road trip to the NC High Country tomorrow so she should get some good break in miles. I'll be eager to report how she does when I get back

 

@AWDDude what dealer did you take yours to?

 

Eastern Washington state, Toyota of Pullman

 

I am also loving this truck. I live in Alaska and my 2.5 hr drive to anchorage is all mtn. Highways with a 65 mph speed limit. I was passing cars going up and over passes at 75-80 mph easy from 4th to 5th gear. I had just hit 1000 miles in my truck and wanted to see what was hiding at 3000 rpm plus and I'm not disappointed. I also have the MT. which is great to choose my gears.

 

Anyone having any luck getting Toyota to do anything about this? When I took my truck in for the seeping rear diff, engine misfire and diff howling, they just told me "normal characteristics for the vehicle." The other issues I am having with the truck I can live with, but the throttle stumble and unpredictable power delivery make it horrible to drive. I am considering taking a huge loss and trading in for something else, and it only has 5500 miles.

 

You should consider ovtune first before throwing away huge sums on trade in losses

 

I looked into that a bit, but it seemed to me that OVtune was geared more towards the AT transmission. Have you installed it on yours?

 

I do, he's making it great for both AT and MT.

 

Agree - while I do have an AT, he's making a lot of great progress. I was on the heels of dumping mine. No more. It's fun to drive now...

 

Do you guys have any concern of it affecting long term reliability? I am hesitant to install something that changes timing, valves, fuel mapping etc. when it was not designed by Toyota with longevity in mind. I don't really know enough about the operation of this type of motor, or the parameters changed by OVtune to know what could be affected. As an engineer, I do know that making seemingly inconsequential changes can have dramatic long term effects.

 

Zero concerns.

 

I share your concerns - to combat my concern, I often keep an OBD app open. I purchased a Carista (but any compatible bluetooth OBD device will do) and use OBD Fusion on my iPhone (Android has the Torque app). This way I can monitor things like fuel trims, lamda, O2 sensors, and overall engine behavior so I can see for sure that things aren't operating outside of parameters. For example, I tried the latest 1.02b tune and it seemed to be leaning out a bit (not obscenely, but enough that I'd be concerned long-term) so I flashed back to the prior release (1.01b) which was GREAT anyhow and I sit pretty close to 1 lamda at cruise, my cats are holding a solid 1000-1400 temp so not too rich, etc.,

I personally (and I know I'm probably in the minority) wouldn't put an aftermarket tune on my vehicle unless I was monitoring, at least initially, what it was doing to my truck via sensor data. So long as I can see what it's doing and monitor any anomalies I feel good about it - and honestly when I looked at the wonky stuff that was happening with the stock tune, i have a hard time believing that Toyota's stock programming was engineered for reliability. Seems reliability has taken a backseat to speed to market (lots of copy/paste/empty stuff in the stock tune), emissions/efficiency with reliability coming in further down the line as one may have experienced with the prior generations.

Plus I don't get the hard jolts, stutters at low rpms under load, and overall the truck is just smoother. If a rough idling, rough throttle, hard and busy shifting tune was designed for longevity then I can only imagine that SMOOTHING out things will improve that even more. Only time will tell though so it's a dice roll either way, but for my piece of mind I feel the truck will run longer and better by getting that stock programming the hell out of my truck.

 

Thanks for the information. Sounds like monitoring the sensors has alleviated many of your concerns. I will have to do my research over on the OVtune thread and go from there. I appreciate the help.