My 4runner V8 done this a good while as I stated and no codes at all ever showed up.
After assuming my shift issue was more likely a "nature of the beast" issue and living with it, it then got even worse so I was getting worried.
Then the other day I was leaving my friends house and I nailed it hard from a dead stop and it stumbled some, then took off. I tried it again and same thing?
I came home and popped the hood and looked at air filter, checking fuel rail,electrical plugs etc.. and double checking to see anything the squirrel I killed a few days before that climbed up under hood and without me knowing I started 4runner, biff, bang, boom (I saw center hood flex) but no damage done to truck, poor guy.
So I pulled my Mass airflow sensor out and it looked ok but I had never cleaned it once. I also saw my throttle body needed cleaned again some, it had been awhile so the next day I went and got a can of Seafoam "SPRAY" with curved tube that inserts into throttle body (see link) and a can of Mass Airflow cleaner and went to town cleaning both up.
After I put it back together and drove it a few days now it's like a new truck. It was running better immediately too btw. I had no idea how bad it really was, but after a week now it has never once hard shifted again. In fact it shifts absolutely perfect both up/down like it done before.
So it's my belief that my big balls should be held every night..Whoops!!!
Oh' sorry guys a rock n roll flashback hit me while typing..
I meant to type:
It's my belief it was my Mass airflow sensor being dirty and the slight hesitation interrupted the shift points as they must correspond together. I only wish I had just cleaned the MAF sensor first and drove it a bit to be sure but I think that is what caused most of it. TB was not that bad and was removed & cleaned before while problem existed so try MAF first.
I don't know yet if fuel milage will change I felt I needed to let its computer settle in a bit before checking that, but it sure drives sooo much better and my nerves sure settled down now knowing it's not a tranny issue so again we'll leave that up to Bruce Jenner...lol
Advice:
Don't use anything but Mass airflow sensor cleaner to clean the sensor as most carb cleaners may damage or leave a film behind. Cost just a few bucks for someone to avoid a future headache is all I'm saying here.
How to clean MAF sensor video. (I don't know him I typed into youtube search and clicked.)
https://www.youtube.com/watch?v=gRfaPfTcfOM
Sea foam says don't spray sea foam into MAF sensor, insert tube somewhere between the sensor & TB but best directly into front of TB.
Sea Foam "Spray" video if not removing TB to clean:
https://www.youtube.com/watch?v=u6UeJXkzDW8
Hope the fix for others here is as simple...Best of luck and a big thank you to everyone "again"!! Until next time...OMG! There will surely be a next time too..
Peace!
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