sc93

So when I let of the gas coming off a 0-50 mph romp, the rpms start going down slowly, then the drop suddenly to idle RPM's. Then when I slow down and press the gas, engine revs but doesn't want to go anywhere. Almost like the tranny isn't grabbing if that makes sense.


This is a 93 Z28 700R4/4L60 btw. 3.23 gears

Also, the shift points are low. In OD at WOT from a stop I floor it, and it goes to 4500 rpm and then shifts. Doesn't go to redline.

Any ideas?

Kris93/95Z28

Might be your govenor in the transmission.

I know when my transmission was rebuilt the govenor needed to be adjusted because the car would shift at a very low RPM about 4,500~5000 at WOT.

For the low idle deal, my 93 would do the same until I replaced the Idle air control valve....That really cleaned up alot of problems

Gripenfelter

Sounds like your Throttle Position Sensor or TV cable.

My TPS was shot and my car would shift at 5200rpm instead of 5750rpm.

I put in a new one and it shifted at 5800rpm.

Clean your IAC while you're at it.

sc93

Ok thanks for the input.


Where are the TPS and IAC located? Can I change these myself?

Thanks

Gripenfelter

The TPS is the black semi-round plastic piece on the passenger side of the throttlebody held on by two screws.

The IAC is on the bottom of the throttlebody. You will have to remove the throttlebody to get at it.

Piece of cake.

12SCNDZ

You're input sprag inner race lugs are broke.
Your TPS has nothing to do with your transmission. It will only affect a 4L60E equipped car, which is electronically controlled. Your car has a 700 which is TV, and governor controlled.

sc93

input sprag inner race lugs ???

please explain, I've never heard that before.

What do they do? Where are they? How do I replace them?

shoebox

Tranny innards. Unless you can rebuild the tranny, you need to take it to shop.

sc93

thanks, that's what I figured

sc93

Is there anywhere I can get a repair manual for the 700R4 (4L60) ? I am interested to see expanded views of internal components and such, to see how the thing works, and where everything is.

shoebox

A factory manual will tell you everything you need to know.

GPZ1100

to get a stick shift next time! (couldn't resist).

I had similar issues with my old boat (an 84 taxi cab).

Car would granny shift, at WOT, the revs never got above 4000 rpm (84 vintage, 305 with 700r4), etc etc.

I got so fed up with it, i swore that would be the last auto i'd ever get. Been driving manual since.