Manual surging in 2nd

Occasionally when I have to hammer down to get the truck moving quickly 1st gear accelerates perfectly but about halfway through 2nd it feels like the engine surges, that's the only gear it will do it in. I've had the problem at cold and normal operating temps.

I don't want to make a trip to the dealer only for them to just say they couldn't replicate the problem or say it's because I have an aftermarket airbox installed.

Is it from variable valve timing kicking in or is there a TSB out there to fix this?
I tried searching around but I couldn't find anything about the 2019s, if you are a better searcher than I, I'd appreciate a link I could follow. Or if you've had this issue and got it fixed even better.

Thank you

 

There are TSBs for this. I looked back through my emails to my dealer when I had them done. It looks like the way I worded it to them is TSB 0058-18 is specifically for the manual transmission and is supposed to help with smoother shifts. TSB 0125-18 is supposed to help with gear surging. This is for 2018+ MYs which it looks like you have a 2019.

I didn't specifically have any issues but had them done anyway and did notice a difference.

Hope this helps. I'm sure others will chime in with more knowledge than I have.

 

Apparently there is a TSB for this that is a ECU torque/power curve update. Good luck convincing your dealer of this as they don't have any knowledge of this for the MT. Only AT. But, once plugged in there will be an update you can run for MT.

 

Do you have TSB number for this?

 

Nope. I've read on this site people are getting this done to their older 3rd gens and when I asked about 2 months ago when I had to get an Oring and gasket for my HPFP and they had no idea what I was talking about. Shocking.

 

Sounds like you are ready for a tactrix cable, vf tuner, and a tune pack!

 

Sounds like a vacuum leak on your aftermarket CAI...put the stock one back on see if the problem goes away as I suspect it will.

 

What rpm, and describe this surge. Is it just a surge of more power, or is it bucking? Or...?

 

Sorry, but there are no published ECU updates for 2019 or 2020 Tacos. There are two ECU IDs for 2019s, but a TSB has not been dropped yet.

Just in case, there are four ECU TSBs for MTs:

TSB-0058-18 for 2016s through 2018s
TSB-0125-18 for 2016s through 2018s
TSB-0013-19 for 2016s through 2018s
TSB-0043-20 for 2016s and 2017s​

The first three all apply the exact same software file (CUW files).

 

I have the same issue. It's like riding a two-cycle dirt bike and hitting the power band. Often when not needed. Ask about a fix at the dealer last week. All I got was a funny look.

 

noticed something similar on my 2020, I assumed it just kicked into some OD mode because I put the pedal down enough, our '95 4runner did that, but maybe a MT shouldn't?

 

The surge around 2,000 to 2,500 is VVTi, and the intake plenums opening up (ACIS) is the boost feel at 3,500. Lowering that ACIS value gives better low end torque and much less of the boost / surge feeling.

There are throttle maps for each gear, including neutral. Talk about messing with the minds of MT drivers.


There is a fix for both of these issues. OVT / vF.

 

I've looked for vacuum leaks everything is tight and without a smoke machine I didn't notice any leaks. It rarely happens, maybe 1 out of 50 accelerations.

I'd say around 2500 rpm, it feels like the truck realizes I want more power than it's giving and the power increases. To me it seems like a tune problem not a mechanical problem.

 

It is, IMO.


The way that I was able to consistently reproduce a surge was to drive for a bit at a steady pedal. Then, quickly and smoothly get pretty deep into the throttle. This would cause a stumble and a surge. My guess is that the system goes into some steady state mode and gets all flustered when you want more throttle?

 

Don’t need a smoke machine an easy way to find a vacuum leak is to remove the intake tube from the throttle body and start the engine...cover the TB with a plastic lid from a coffee can, Tupperware or whatever...if she stalls immediately your good if she runs for a bit look and listen for the hiss the engine will find the leak for you.

 

Oh ok, thanks for clarifying, you would know better than I would. I find it kind of surprising that the 2019s don’t use the same TSB since they’re essentially the same as the 2018s. But, I guess if the ECU/build is newer that would be like downgrading to an older patch (in theory).

Would the new trucks not get all the TSBs in the newer ECU/build, assuming that’s how it works?

In any case, hope they release TSBs for OP soon!

 

You're welcome!

It is not really a downgrade, just that there are new features and functions with each MY that would need a different ECU ID.

I would assume that a newer MY would at least have the latest TSB updates, but it seems that the 2020 folks have some of the same complaints as some folks with older Tacos have also. The only sure thing is to keep any eye out for ECU TSBs as they do significantly improve the driveability and seem to give small power bumps also. Certainly for me, the last TSB (04B14) felt very different than the one before it (04B13).

It has been a while and no one really knows yet why there are two ECU IDs for the 2019s. We certainly know why there are multiples for the 2016s through 2018s.

 

An OV tune is on my wish list but I don't have the money for it right now. Maybe if a local shop could flash it for $500 I would do it but $800 plus I'd need a laptop is too much right now.

Another mod on my list is the 2x4 lo gear mod, the reverse gear ratio is absolutely horrible. I've stalled so many times backing up steep driveways to unload materials, it's so embarrassing to stall out in front of a customer.

 

I actually realized that the other day. When in Neutral and you blip the throttle, not much happens. When you put it in 1st, clutch in, the throttle response was instant, just like a cable throttle. I couldnt believe it, i was shocked haha.

So what i noticed in all gears, is that when the gear is selected and the clutch is in, the throttle response is much quicker than just neutral.

Why the heck would they do that?
Because when rev matching, the shifter should be in neutral...

 

Yep. Nutty.

Because they can? Engineers . . .