87 Z28 auto trans. The problem is starting out, I have to get the rpms up to about 3500 before it will shift out of 1st. Shifting into 2nd at about 3000 after that it shiifts ok. If I let the rpms drop it down shifts immediately and the process starts all over again. What can I do? People have said it was a vacuum modulator but others say this trans (700R4) doesn't have a vacuum modulator?
Ant suggestions?

 

Maybe the TV valve is stuck.

 

Where is the TV valve and how do you unstick it?

 

I feel your pain. I'm going through the same thing. This is what I've been told to check.

1) The pump. With a catch pan in place, disconnect one of your transmission cooler lines and run the car for a couple of seconds (not too long) to see if your pump is pumping. You got no fluid coming out, then your pump is bad. Remember to refill fluid levels before running it again.

2) The governor. Check your governor for sripping and wear. Its under the cap at the rear of your transmission--driver's side.

3) The throttle valve (TV) linkage. This one has me scratching my head. Maybe someone could help us both by giving the procedure to this.

4) The Vaccum modulator. My dad (confused ford guy) told me that I might check it. Wrong! 700 R4's don't have a vaccum modulator so yours is just fine.

5) The Pressure within the tranny. Someone hinted this to me. As far as I can remember, there is a valve that can be checked to determine the pressure--if you have the propper tools. It is on the driver's side just a bit above and forward of the governor.

I hope I've helped you a bit and maybe someone else will color the picture a little more for the both of us. Good luck.

 

The TV cable is connected to your throttle lever. I believe under the throttle cable. It has a plastic sleeve where it slides in and out to be at a certain position to have the line pressure your tranny needs to shift right. To adjust it, look on the tranny board and follow transfixleo's method.

 

After checking the TV linkage, pump, pressure, governor, lines, and everything else I could with and around the tranny, it turns out that the problem was the catalytic converter. It was the stock converter and it went bad. The excessive backpressure threw things all out of tune and kept me from shifting. It might be worth your time to check this. Good luck.