Trottle Body can not acheive WOT because of Tansmission TV Cable
 

I have a 93 Z28 Automatic. My problem is that the butterflies on the throttle body will not completely open up when the TV Cable (Aka. Detent Cable) is set at the position where the tranmission shift points are correct. By sliding the adjustment towards the front of the car, thus realeasing tension from the cable, the throttle body will then reach WOT but the transmission will shift into Overdrive at 20mph. Does anyone have any ideas whats goin on with this or how i can fix it. A guy told me I had a 4L60E tranny but I thought I had a 700-R4. Altough I dont know if the TV cable attaches to the transmission or to a control module the adjusts the shifts points electronically instead of mechanically. Any ideas would be appreciated...Thanks, Ryan:confused:

in 93 the tranny is a 700R4. Have you done any transmission work to it? Shift kit, transgo kit? How are you adjusting it? The best way is have someone hold the gas to the floor, then push the button on the TV cable, then push the housing of the cable towards the firewall. It's possible that your TV cable is streched and you do not have the proper geometry anymore, thats why you have to make up for it. Also the lever in the transmission that attaches to the TV cable might be messed up. However its strange that you have adjust it so "loose" to get it to shift right. Proper TV settings are crucial for the life of the trans. If the things I have mentioned aren't it, the more experienced tranny guys will have to help out. Also, does the car drive any different when you put it in drive, and when you step down hard on the gas, does it downshift?

Well the tranny has had a complete rebuild. They didnt install a shift kit but they did beef up the valve bodies and servos and some things like that. Although i didnt have to loosen the cable to get it to shift right i had to move the adjustment towards the firewall which tightened the cable. I have had so many wierd ideas of what could have happened. I wonder if the accelerator cable could have stretched some because if you apply just a little more force to the throttle body linkage while it is floored you have get it very close to WOT. :confused: Who knows? haha

Just for clarification, the 93 A4 is actually designated as a 4L60.

RyanU1, take a look at the speed density link in my sig, and look for a member with the screen name knightfire. I would think he could set you straight.

Sonnax Ind. "TV Corrector"!!!!

Toyr transmission is a 700/4L60...Without the "E", because it's still governor/hydraulically shifted. An "E" is electronically shifted.

The TV cable helps controls your transmission pressure, and it is directly connected to the TV linkage in the transmission. The reason it makes shifts later/earlier is because it raises/lowers pressure. The governor actually controls the shift points.

Since you've only messed with the t-body, let's start there, though. Try doing a search for SONNAX INDUSTRIES. Look for something called a "TV Corrector". It goes on the end of the cable, and it should help your adjustment problem.
It is, however, possible that your TV valve has stuck. Snap the cable a few times to see if it makes any difference. With the car running..pull the cable a few times and let it snap back.


Frank
All-Trans Transmissions

Why would he need the sonnax device? If the valve body was setup right, it should work right. I mean it's not like he put a carb on it and it wouldn't work.

I have a 700 in my vette. The way I was told to adjust my tv cable was to hook up a pressure gage to the test port on the drivers side of the trans case. Read the pressures with the cable unhooked and hooked up the difference should be 5 to 10 psi with the hooked up pressure being the higher of the two. My pressures were in the 70 to 80 psi range if I remember correcly. Also you need to check for an instant pressure rise. Pull on the tv cable as it is hooked up, or tap the throttle to make sure that as soon as the gas pedal moves so does the trans pressure. Once you have that set, drop the pan. Have a buddy push on the gas pedal and make sure the tv valve is operating correctly. At full throttle it should push the valve all the way in.

If the trans rebuild shop did their job right, they probably installed a spring in the tv valve to help it return to the closed throttle position to keep it from getting stuck. Once you have verified the tv valve is working and your pressures are set check for WOT. If your still not achieving WOT you'll need to play with the throttle linkage. The best way to do this is to put a spacer on the throttle cable down at the gas pedal. Lift the pedal up and add a zip tie or something that will add a little more travel to the gas pedal. What you fighting against to get WOT is the extra spring they installed in the tv vavle and your throttle cable is stretching before you get to WOT. I had this same problem with my vettes throttle cable.

To adjust the shift points you'll need to play with the weights on the govenor. Not the tv cable. So be sure you set up the tv cable correctly. Then find someone who's played with govenors before to get it straighted out. You probably need to remove weight from the govenor to raise the shift points.

Another good place to look for TV cable help is a place called Bow Tie Overdrives.

The cable adjustment has nothing to do with the way the valvebody was set up. The cable is a physical link between the t-body and the TV linkage. If the cable is adjusted too short, it will ratchet out and allow lower pressure. The TV corrector is a spring that goes on the throttlebody end of the cable that allows proper adjustment without ratcheting out of adjustment.

Frank

http://www.transmissionspecialty.com/parts/main.htm

Go to all parts...Then to GM multiple part...Then to #AS1-01K

Frank

dont want to hijack, but since you guys are on the subject my car has trouble getting to WOT. pedal feels real smooth with light pressure on it, then to go WOT i have to really slam the pedal real hard. checked it out today and there is a bit of travel from the light pressure point to slamming the pedal. is this normal w/ the 4l60 trans?? ohh almost for got, the car has a BBK 52mm TB.

Man you guys have been such a help. Im gonna print out all your replies and take em to my tranny shop. Cause it always seems that the problem that your having, they dont know how to fix. So hopefully I can start trying some of these ideas today. My and my hometown rival are supposed to race saturday and i need to dyno tune my motor before we run. Thanks so much Ryan