Shifting Issue

[ThirdgenTa]

I will start from the beginning. So the other day I removed my entire throttle body so that I could clean inside of it and clean the MAF sensor. I took the throttle linkages off and undid the wrap around part of the spring. I removed the sensors and put them back in. So I reinstalled everything where I thought it went. The only thing I was unsure of is the connectors. I installed them in the only places I could get them to fit. I then started the car and let it run to make sure I put everything back right, but didn't drive it.

Fast forward to this morning. Took the car out and it was not shifting. It would go up to 4500 rpm and then I would have to let off and it would go into 2nd. It seemed fine with all the other gears. I got onto the highway and was doing about 65mph at a steady pace, but when I gave it just a little bit of gas over 2500 rpm, it felt like it would downshift and shoot back up to 4500 rpm and not shift until I let off.

I had RareGmFan take a look at it and drive it and we came up with a few theories like it could be the computer or that it's only shifting with line pressure. He looked at the area I worked on and said it looked to be all in order.
Anyone have any useful ideas? I would rather not drive the car around like this and damage the Trans.
Oh yeah and I did check to make sure that the sensors were pushed in tight. Im just not 100% positive they are in the right area.
Here is a pic of where I installed them.

Click to read more...

 

[KagA152]

whatd you use to clean the MAF sensor? try unplugging the MAF and drive it again, if the MAF got contaminated or damaged load calculations will be fubar and cause shifting problems. The TPS also plays a role in load calculation. If you have a scan tool available you can monitor the MAF and TPS to see if theyre going crazy

 

[ThirdgenTa]

whatd you use to clean the MAF sensor? try unplugging the MAF and drive it again, if the MAF got contaminated or damaged load calculations will be fubar and cause shifting problems. The TPS also plays a role in load calculation. If you have a scan tool available you can monitor the MAF and TPS to see if theyre going crazy

Well the funny thing is that I didn't even end up cleaning it. I wasn't sure which sensor it was so I just removed them and looked at them and then reinstalled. Then it was pointed out that the top one is the MAF. You might thing I am retarded put the only MAFs I have worked on and familiar with is the in line ones from Thirdgen F-bodies. The only cleaning I did was put throttle body cleaner on a rag and wipe down the inside of the throttle body real well.
The only one I did not remove is the one on the top facing the side in the picture. I did not have the right size torx and I ended up breaking a head off so I couldn't couldn't remove it. You can see it in the pic. I think it might be the IAC?

 

[Turbocharged400sbc]

the only thing i could think of is the maf got damaged somehow, should be no problem to unplug it and run it as speed density to see if it shifts more normally.
did you disconnect the battery? this can reset learned adaptives that a worn trans would require to "shift normally"
fluid level running at operating temp in park is good?
really the only thing i can think of is that your really close to setting the dreaded "max adaptives" code and the pcm was reset so its going back to the programmed values till it learns that your trans is worn out and maxes line pressure to get it to shift...nothing youve done would harm shifting, all your connectors are in the right spots, the broken iac screw wont affect anything as its sealed with an oring (though i find it odd that the screw that normally breaks off is the lower one and your upper is the one that broke lol)

 

[10sec]

Sounds like the TPS is going nuts.

 

[ThirdgenTa]

Sounds like the TPS is going nuts.

Thats the one that connects to the flap in the TB right? I took that out and maybe I didn't position it right???


And TBC400- I am going to start with disconnecting the battery. I had a code from last week that I never cleared (loose gas gap). Maybe it will set another one?

 

[Turbocharged400sbc]

if you have a code reader go for it but a evap leak code wont cause any issues, you may have not installed it right and possibly damaged the carbon track inside the tps but you would also notice hesitation and it would chuggle/fall flat in one area of the pedal travel. any running issues besides the shifting?

 

[Turbocharged400sbc]

for refrence when you install the tps youll want to have the bolt holes offset clockwise a little bit, then once the surfaces are flush rotate it counter clockwise to line up the bolt holes. this puts the least amount of stress on the arm

 

[RareGMFan]

I drove it for a few minutes yesterday. I started out just accelerating very gently (some might say like a normal human being, perhaps), and it shifted perfectly fine. Solid shifts, and right where they were supposed to be. I gave it a bit more throttle the next time I took off from a stand still (still well under 1/2 throttle), and it stayed in first till I eased off the accelerator a bit, then it shifted into 2nd. It did this very consistently. The trans seems fine otherwise, and the car is running smooth.

The only thing I noticed wrong from visually inspecting the sensors is that due to the top/left bolt on the IAC not being there since it broke off in the throttle body, the sensor is a bit loose. Nothing major, but you can definitely wiggle the sensor around a bit.

3rd - If it's going to set a code, it doesn't need you to reset the PCM to do it. It would already be there. You should get it scanned even without resetting it just to make sure no codes other than the EVAP have been set.

 

[bikrboy128]

Sounds like the TPS is going nuts.

this.
back when i had my gtp i took all the sensors out and cleaned them (like you did) and didnt re-install the TPS right.

 

[smug]

My TPS went bad making my car shift funny

 

[ThirdgenTa]

Well I actually decided to buy the right tool for the job this time..Makes it much easier. I took everything apart and I reinstalled the tps the opposite way that I had it. It went on much smoother than before. Everything is back together now so as soon as my roomy moves her car I will take it for a test drive and follow up.

 

[Turbocharged400sbc]

annnnd?
i have spare tps's if you did manage to damage yers...but since your near the picknpull you can snag one pretty easily

 

[ThirdgenTa]

annnnd?
i have spare tps's if you did manage to damage yers...but since your near the picknpull you can snag one pretty easily

Just took it out a few minutes ago and it's shifting almost as good as new!
Thanks!
THe only other thing is the SES light went back on as soon as I started the car. Not sure what that is about.

 

[Turbocharged400sbc]

so the tps arm was behind the throttle blade bar?
if you had a scanner you woulda saw the tps voltage never change lol