So got a new to me 79 Z28 the other day and it has a problem with the automatic transmission. The problem is that sometimes it doesn't like to shift. Most of the time it doesn't like to shift out of second. It just gets revs the rpms and accelerates slowly. Furthermore, sometimes if i coast and slow down enough for it to shift down to first but dont stop completely then accelerate again it doesn't always go into second, but this is rare. On occasion though it works great with no problems. This usually happens if the car has sat for more than a day without being driven. But it goes back to the 2nd gear problem after a few miles.

So there you have it. I know nothing about transmissions but if someone can give me an idea so I can research it I would appreciate it a lot.

 

1) Make sure the vacuum line from the intake manifold is still connected to the vacuum modulator on the trans.
2) Make sure the kickdown cable is still connected to the carburetor. At WOT (wide open throttle), the cable should be pulled out all the way.
Those two things work in conjunction with each other to control proper up and down shifts.
3) With the gas pedal planted to the floor, make sure the carb butterflies are straight up and down.

 

Thanks for the reply. A few more questions though if you dont mind.

Each number is in respective regards to your post above.

2) Is the kickdown cable the one just below the throttle cable on the carb ? If so then is it supposed to have a lot of slack in it ? I can move it at least an inch in both directions. The "adjustment hole" is in the middle of the bolt post and the nut is not tightened against it. Is this how it is supposed to be ?

3) Should I be checking the butterflies with the engine on or off ? I have not dealt with carbuerators before. Also it has a holley double pumper on it. I dont know what model though.

Thanks.

 

okay, so i checked the kickdown cable and its fine, the carb is fine too. i got the modulator changed today and guess what ? ......... i still have the same problem.

so any idea of what it could be now ?

thanks.

 

I talked to a few tranny shops today and one of them seemed pretty confident that it might be the governer due to the fact that the previous owner was constantly smoking the tires and that the governer was a common problem with people that did this.

So does this sound logical to and fit the symptoms to you guys ?

Thanks

 

I don't know about the smoking the tires and governor connection, but it would be the next logical thing to suspect given it's not the other two things. Could be the weights are hanging up, guess you'll find out.

 

So who should I believe ?

I have the one guy (from the slightly out of town one man operation shop) that is confident that its the governor.

Then i have the local rip off shop that wants me to fix other problems first because they dont want to drive it in its current condition before they even check it out, but they are trying to tell me that the governor has nothing to do with shifting up, it controls down shifting. Is this true ? From what I have read I dont quite think that is correct.

 

The governor has everything to do with upshifts, along with the modulator and cable. You can raise or lower your shift points by changing the springs and/or weights on the governor. That guy doesn't know his stuff. There's a good video on youtube showing how to play with your governor, lemme see if I can find it.

 

Oops, got sidetracked. Here's what the governor is about. Maybe show it to the rip off shop too, but I'd steer clear of those "experts".

 

Alright. Got the governor checked out today. Not the problem. Looks like its a tranny rebuild for me !! He also said that my shift cable was fried due to something not being grounded properly and it was grounding through that cable. ????

Anyways, long road ahead.

.... this sucks