Manual Trans RPM while shifting to 5th

Hey folks,

I figured I'd join and ask if people have the same issue/"feature" that I have encountered. Truck is the 07 4 banger Prerunner 5 speed stick variety.

Issue is RPM "hang" while letting off the gas while shifting into 5th. What happens is, you clutch in and let off the gas, and the RPM just chills up at where you left it and SLOWLY comes down. To shift properly, you have to wait for about 5 seconds to synch the engine with the drivetrain in the new gear....or you just let the clutch eat it.

This doesn't happen in other gears, only fourth to fifth. It also doesn't happen while the truck is not warmed up to operating temp yet, nor does it do it at ranges outside of about 1500-3500 rpm. I don't normally shift at 3500 unless I am really needing to move, and I normally shift about 2000.

I believe it is a leftover from the automatic computer where it maintains partial throttle when you let off at speed to not jerk the car. Funny thing is, that four banger doesn't possess the oompf to do that in anything but second or lower.

I've talked to a dealer, who won't get back to me / knows nothing. I'm also diving through the tech documents on the internal Toyota network to check for it, but it's slow going. (I do work for the company, but I'm at the Indiana plant, not NUMMI, so we don't do the Tacoma. Shameless Plug: Buy a Sienna, Highlander, or Sequoia! )

I guess I am going to have to resort to some sort of tuner software, if I could find it. Ideally, I could modify the programming in the truck's computer to not do this.

Anyone seen, heard, or accomplished anything on fixing this?

Thanks.

 

If we are on the same page it is an emissions thing. It causes the engine to burn off what is left instead of dump it out the exhaust.

 

minr does the same thing i wish it didnt!!!

 

So, anyone know of a reprogramming fix?

 

Tampering with the software to cure a slightly hanging RPM? Seems the risk / reward ratio is not worth it.
My experience is that this doesn't even make for a rough shift. Ignore it. IMO
( I don't think anyone has even hacked the newer ECU's, to figure out the encryption)

 

I have the same problem with a 2009 Tacoma, 4 cylinder and it is frustrating the hell out of me. The dealer is of no help and I have phoned Toyota Canada who refered me back to the dealer. I have also written, a not so nice letter, to the president of Toyota Canada. I suspect if they solved this problem they might just find the solution to all the random acceleration problems they are being sued over in other Toyota models. In my case it is not floor mats or a sticky accelerator, I am convinced it has to do with the programming of the controlling computer. It may be fine to ignore the problem, but when you need a clutch Toyota will be very happy to charge you and tell you this is normal wear.
Please

 

stay on top of the problem and post your solution.

 

Sounds to me like he knows what he's talking about.

Since I wrote this thread a while back, I checked with regional dealers, and, with the creation of the chief quality officer position within TEMA, I emailed him and they're working on evaluating the problem. I figured, with dealers giving me the run around, it was time to work from the top down.

Fortunately, I work for TEMA PE, so I can get ahold of most folks in Toyota.
(TEMA is Toyota Engineering and Motor Manufacturing North America, if it helps clarify things.)

 

I know this has been beat and I have seen these videos of the tach/what is descibed, but my truck does not do this. RPMs drop sometimes too fast for me shifting to second due to having to shift slower into that gear. I believe it's happening and may be due to some people pereception, but not here. That should make some people flip out i'm sure. Overall it is slower then other vehicles but that's another story.

 

The rpm drop is very inconsistant, AC load, fan clutch, and engine temp all affect RPM drop. I found on my 2009, it never dropped at the same rate twice. Solution; don't buy a stick.....

 

Has there been any findings as to the issue with this?
My '08 has exactly the issue as described in the origanal post.

Thanks,
chris

 

My 2010 doesn't do this, let off the gas to shift and it drops normally (every time, so far, 6000+ miles), at least "normally" compared to all the other manual shifts I have driven, except for a 71 Pinto, where the RPM's would hang for a second then slowly drop (emission-related crap), but that was easily disabled by "adjusting" the vacuum device that controlled it, and I disabled it with the result of normal shifting and significantly better gas mileage. Absolutely none of that stuff on my Tacoma, so if it starts doing that, I will have to think something is wrong.

 

I just bought a 2008 and it was very noticeable. I had a 2002 tacoma and had no problem with engine speed dropping the second you let up on the gas. Yesterday when I got off the freeway and stopped at the end of the ramp it took about 10 sec before the idle dropped. It just sat a 1500 rpm and slowly dropped back to normal idle. This is my 3rd tacoma but my first with the V6 and never had this problem before.