I have an 88 trans am with 305tpi and 700r4 automatic. when I bought the car it had had some engine work done, and it seems like it took a bit too long for it to shift from 2nd to 3rd.
I tried adjusting the tv cable by pushing the little metal button in and then sliding the black end of the cable back until it was as far back as it would go. then I moved the throttle to the widesst open position by hand,which as i understand sets the adjustment. I tried driving it down the block and it's worse than ever. The car has only 95k mile on it I don't want to damage the trans. Can someone please help me out and tell me what I've done wrong and walk this dummy through this step by step?

 

Here's some photos. I hope someone will help me. I am pull over at a parking lot now so I don't drive it until I get this set right

 

You did it correctly. You shorten the cable then you use the pedal (not by hand) to ratchet the cable to it's adjusted position.

If that doesn't work then your problems are inside the trans and no amount of messing with the cable will fix it. Mine started late, hard shifting and I tried adjusting the cable. Helped for a few weeks then the trans blew up. I masked a bigger problem by messing with the cable. There is only one correct adjustment and that's as above.

GD

 

This video makes it even more confusing! This person says you pull the cable OUT not push it back!

 

Thanks GeneralDisorder,it wasn't shifting bad before,I just wanted to set it to be sure it was right because it seems to be "stacking" 2nd to third shifts in D (non overdrive) mode.
Can you go over with me again how I set this right? I just watched a YouTube video and its saying the opposite.

What I did was push in the metal side button and push the black plastic end of the cable back as far as it will go,then I let off the button and by hand pulled the throttle body wide open as far as it would go.
Should I have instead used the gas pedal after?

I also didn't hear any "clicks".

Thanks for any help you can offer. Sorry to sound so stupid

 

Its accomplishing the same thing either way. That method just requires a helper. Either way works. I installed a built race spec 700R4 after mine went out, adjusted per book as I outlined above and it works perfectly. Chances are if you can't get it to shift right using the method above then the trans has some kind of problem internally.

GD

 

Yes do it as you did, but use the gas pedal instead of rotating if by hand.

GD

 

Ok,I just did this again-
I pushed the metal button on the side of the cable,then I slid the black plastic end of the cable as far back torward the firewall as I could,then I released the tab. Then,this time I got inside the car and pushed as far down on the pedal as it would go and heard one "click" or snap sound. am I doing this correctly this time? I have not driven it yet. I don't want to damage the trans if I am not doing this right.

 

Thanks "GD",I sincerely appreciate your advice. I did it again but using the gas pedal after this time. I pushed it down as far as it would go and heard one "click" or "snap". Hope I am doing this right

 

Ok,I took it for a test drive and now it's shifting at 16mph,27mph and 46mph. Before it shifted at 15-25 and 40mph into overdrive. I've made it worse! What am I doing wrong?

 

Am I supposed to actually disconnect the cable end from the throttle before pushing the black plastic part back? In this video this guy says to do that. I thought that wasn't necessary.

 

I tried it again. Pushed the button in,pushed the black end of the cable as far back as it would go,let go of button,got in car,floored it,heard a "snap" and let off the gas. The end of the cable is sticking this far out now. Is it supposed to make a "click" or "snap" and pull out when floored?
Here's a photo of the black plastic part sticking out further afterward

 

That's fine that's exactly what's supposed to happen.

 

Ok,tried it again and now it's much better! Shift points are now 12-22-30-33 and then it goes into overdrive at 40. Does this sound normal?

 

Depends on throttle position but sure. It doesn't sound bad. It should hold 3rd as long as you don't lift your foot. The non corvette TV sleeves don't allow full throttle overdrive.

 

Thanks General. It does hold third and those numbers were at light,normal throttle,no wide open. It's better than it was when I got the car. Just wanted to see if it was in the ballpark or should be dialed in more.
When I got the car I had to adjust the idle down because it was idling high,like around 1000 or more rpm. I don't know if my adjusting the idle screw also changed the tv cable position a bit too.

 

You adjusted the idle by following the link below (or attachment), yes? Because there is no idle adjustment, in the classic sense) on TPI inducted engines.

https://www.thirdgen.org/tpimod2/

Thinking out loud: I doubt messing with the adjustment screw affected the TV cable adjustment; WOT is the same regardless of the throttle linkage starting position.

 

It can also be a stretched cable that is no longer the proper length to work correctly. In which case, the only solution is to replace the cable.

As you point out. Messing with the cable and fiddling with it will mask a problem. The cable is self adjusting until it becomes too worn to adjust properly.

 

I'm pretty sure you should hear more than just one click. I put a new cable on when I put in my rebuilt trans and it has a soild 3-6 clicks IIRC. sounds like the cable is stretched.

 

There was only one click when the pedal was depressed fully to the floor.
It seems to shift alright now.

 

My 1986 cable works just great with my built race trans and clicked once or twice. I think it may not register as separate clicks either if you hit the throttle quickly.

I can't see the cable itself stretching. The adjustment insures that shrinkage of the sheath is not a factor. I don't buy the cable being stretched theory. I've worked on thousands of cars from 1950's to 2016 and I've never known a braided steel cable to have any significant amount of stretch. There's less load on the TV cable than a standard throttle return spring on a throttle cable. I would have to see it and have it proven to believe it. Barring some kind of excessive loading or corrosion....

GD

 

It exists. Over decades and 10s of thousands of miles its not inconceivable to think that the cable would stretch. Its a stranded metal cable.

I've seen it on my own car that wouldn't shift properly and I ended up replacing the cable and it would then shift properly. I followed the adjustment process and the cable would click once, or not at all. It was too long to adjust properly.

Replaced the cable and adjusted in the same process and suddenly the trans shifts properly.