I recently purchased a 95 Z28 with an automatic transmission. To my knowledge the only modifications it has had done to it are a K&N cold air intake, Jet Stage 2 ECU chip, and Flowmaster muffler. It has 205,000 miles on it. It has come to my attention that if I floor it the car will not shift into second gear. I tried drive and over drive, tried from a dead stop and while rolling at about 20-25mph. It shifts fine until you put the pedal to the metal, then it revs all the way up to redline until it starts beating off the rev limiter and just stays there until you let off. Felt like the torque converter was slipping but I don't know. Almost felt the same way a standard feels when you have a worn out clutch and you try dumping the clutch at about 4-5,000rpms. You know how it will just rev away and torque the whole body away but the clutch just can't grap the flywheel. My car feels just like that but only if you floor it. Any ideas?

Could the Jet Stage 2 ecu chip be causing problems? I don't even know exactly what all it is supposed to do besides change the fuel curves.

Somebody, if you can, please shine some light on my situation. Thanks.

 

I forgot to mention, when it is in Drive it won't switch into 4th. You can be cruising along at 45-50 in drive and it stays in 3rd until you switch to Over Drive, then it kicks into 4th promptly.

 

may be computer related but, sounds like maybe a problem with the lockup solenoid. doubtful anything to do with the converter. at worst some clutches are roasted. Sick

 

What exactly is the lockup solenoid or what does it do?

I read a few other previous threads with guys complaining about their trannies slipping from the launch and acting like a blown clutch. But this is wierd.... I mean it launches like a fricking bat out of heck but it just won't upshift for anything until you let off the throttle then it just kicks into 4th and coasts. I don't know... let me know guys.

 

Check the fluid level. Easiest thing to do. If it was the torque converter, it wouldn't move at all.

 

Torque converters always have a certain amont of slip, but when they break, the car is hardly able to move. The TCC is used to eliminate slippage when the car reaches a steady cruise speed, but is disengaged at WOT so it is out of the picture in your case. What I think your problem may be, is that your transmission has seen better days and needs a rebuild, could be slipping clutches, low line pressure, etc... The Jet thing is not a chip, as the 95 cars do not take chips, what you probably have there is a reprogrammer and there is a possibilty that the shift pionts have been set too high and the engine is hitting the rev limiter before the transmission is told to shift by the PCM. Before you do anything, either unplug the programmer, if it is one of those that stay hanging on the diagnostic port (dongle), or reset the PCM to stock if you have the type that actually reprograms the car. IMO these gizmo accomplish very little in 4th gen cars, as GM has done a very good job of getting all available power out of the stock engine.

 

im currently having the problem with my Z and forunatly i know what it is. You have burnt clutch plates, also hate to tell you this, but the tranny is on it way out, which means your going to need a new transmission, torque converter and the whole 9 yards. I just took mine into the shop today and won't have it until friday. I had the same exsact problem you were having and im confident its the problem. I'm paying $1,500 to get it fixed, however i know someone who will do it parts and labor for that cheap. Firestone was ready to charge me $2,400 to fix the problem, i nearly fainted when i heard that. Anyways, good luck lol.

 

Well that blows bad! Oh, well. I did buy it for a project so guess that's a start..... hey, your Camaro looks exactly like mine.... maybe once it's fixed u can borrow mine and go back and say it's still having problems.

So automatic trannies have clutch packs in them???

 

yeah, from what i was told, only reason why i know the problem is having is cause i have/had the same exsact problem. I'm no pro on cars, but i know my stuff pretty good.

 

Does my car have the 4L60E or 700R4? Is one a manual and one an auto or what?

Also, whichever one mine has, where is the best place online to buy one? I can replace all of this stuff myself but I am not simply wanting a stock tranny. I don't mind paying a little extra if I can get one that is beefed up. I intend to rebuild the engine and bump the power level up a tad so I want to make sure my tranny can take the abuse. Any suggestions are great. Thanks.

Also, thanks to Z28ster for pointing me in the right direction.