Hi all. I have a 91 Z28 with a stock 700R4 for now. Whenever I slow down to turn at red light or stop sign it shifts into what seems to be 3rd gear or overdrive instead of 1st or 2nd gear and it shakes and shutters very badly. Also if I just happen to get into a skirmish with another driver whenever It gets above 110 mph it starts to cutting out as if it's not getting enough gas or maybe the governor is stopping it from going any faster. As long as I keep it at 110 mph it's fine. Any help or suggestions would be most helpful.

Thx

Kenneth

 

If you are at a deadstop and it is in 3rd or OD, then the car would most likely die. Maybe it's just having a hard time downshifting. Bands? Solenoids? tranny on its way out?

About the 110mph thing, stop street racing! It's dangerous. Although, the tranny/car is probably cutting out. I didn't think thirdgens had speed limiters though...

 

Yeah they did have speed limiters, some of them were set to cut out at 110mph...

As for the tranny issue, have no idea...I do simple stuff on the tranny such as mounts thats about it...

 

91Chevyrs & Z28cross-fire, thanks for the info. I think I will just purchase another tranny or have this one built. If it does have a limiter in it could it be taken out with the rebuild or will I have to get a custom chip?

Thx again.

 

I really don't think its neccessary to jump into a rebuild or get another tranny. I'd get it checked out first, when I was having problems with my tranny, I took it to my local shop and I gave them a very detailed description of what was wrong with it.

The guy popped open the hood, looked at my TV cable and saw that the cables came loose from the brackets, so he snapped it back in place and it was driving perfect again.

As for the governor, I believe you can buy something called a governor recalibration kit and with this you can recalibrate your shifting points to better suit your need.

If its neccessary and ur gonna be replacing the tranny even if it is good or bad, then do as you wish. But don't jump to conclusions, I thought my tranny was toast when it started acting up and its been running strong ever since.

 

First I suspect that the Torque Converter Clutch is staying applied when you are slowing down. There are several causes to this. First is a bad release switch on the brake pedal. Second the TPS maybe bad. Third there might be a short somewhere in the wiring between the TCC and the ECM making the transmission torque converter stay locked, even though the ECM is not commanding it to do so.

Another possibility is that the governor is hanging up and the transmission is staying in high gear. If the shuddering feels like a when you slow down and don't push the clutch on a standard, suspect the TCC. If it stayed in a higher gear, it simply wouldn't have any power.

Third, TBI F-bodies were goverened to 110 MPH. The fuel injectors stop opening when you hit 110 MPH and re-open when you hit 108. Just a FACT of the stock calibration. There is a way to disable the speed sensor with a switch for racing purposes, but why?

 

Ok Fast355. If the TCC is staying locked could that be solved by simply purchasing a new converter or not? Sorry don't know a thing about tourque converters.

As far as the governor and the factory calibrations to stop opening at 110 and re-open at 108, I ran into a guy close to my home who wants to sell a 78 or 79 Camaro (bottom end of motor knocking) and a sbc 350 bored .60" over with a 10:1 compression ratio all for $800. I think I may jump on this deal and take the 305 out of my 91 Z and put the 350 in with a built tranny and put the 305 in the other car.


Kenneth

 

If the torque converter keeps locking/unlocking it might be dieing. A new one could fix this possibly.

As for the $800 dollar 79 camaro and 350; Why would you want to take a 350 that is KNOCKING and stick it in your car? You also do know that it is illegal to stick an older engine in a newer car right? (emissions)

 

The 350 is not the one in the car. It is on an engine stand. The one in the car is the one that is knocking. The guy told me the 350 is a Vortec engine. Sorry about that, I should have put all of that on my previous post.

 

Birdboy it sounds like your foward run clutches are smoked. My tranny is in a billion parts in my garage for a rebuild. My tranny did the same thing, drive like crap at slower speeds and run great at higher speeds. The first time I rebuilt it I only put a kit in and didn't do any homework or buy other parts. Know I have been doing my homework and aside from the kit I will be purchasing other parts to make sure that I don't have to R&R the trany for a long time. Whether you buy another tranny or rebuild the one you have a new convertor or having your's rebuilt is a must.

If it still moves take it out in front of the house and get one more gooooooood burnout. I did and the car almost didn't make it into the garage. But the street is forever tattooed.

 

I think I will take your advice 91Z28TTOP and lay a long one out in front of the house towards the end of the month. I'll have to resist the urge to do it now just for the sake of having transport to and from work, unless I go and get my motorcycle out of the shop, then it's on.

 

Yup, it gets out the frustrations these cars can build.

 

before getting a rebuild, I'd check the TV cable adjustment.

The cutting out thing is your top speed limiter. www.tpichips.com sells excellent chips that you can get the top speed limiter removed on.

 

Looks like whoever did your "gorilla chipz" didnt take out the speed limiter in it.

An engine built for a 78 Camaro is probably not set up for a 92 Camaro. Remember, 92 engines are roller cams with 1-piece rear main seals and the oil dipstick on the passenger side. Dont give up those benefits. Plus, an engine already bored .060" over is at the end of its life and cannot be serviced again. There is less metal there between the cylinders, so it could run hotter, as well. I wouldnt touch that engine.