94strokedz

iTrader: (1)

I have a 94 Z28 with a 4L60E. Had a precision industries vigilante 3600 stall, now have a new precision industries 2200-2400 stall. If I start the car and start driving right away, the converter will lock up at roughly 45 mph under little or no acceleration. Locks up at approximately 100 at WOT. However, once the trans is warm(15 minutes of running), and I let the car stop at a traffic light, the convertor will no longer lock, at all, ever, until the car sits for 8 hours and completely cools down. Then, the same thing happens. It did this with both convertors. I have a new electrical harness and plate between the valve body and the trans. Don't know if this matters, but it has a transgo shiftkit and a vacuum modulator conversion as well. The solenoids have all been replaced recently as well. Any ideas on what this could be?? Ohh, and it is not a problem with the PCM as according to the Tech II that I use, the lockup solenoid is still firing, but the converter doesn't actually lock up. Please help with this, as it has been ANNOYING me for a good year and a half now.

94strokedz

iTrader: (1)

Any ideas??

chevyhighrider

If your grandma drove it you would probably get a better time at the track

strokedls1

iTrader: (1)

I believe that dave from yank was saying that it can happen from the oring on the input shaft not sealing right. The fluid thins out when it heats up and can't hold the pressure to maintain lock up. You may want to pm yank and get the specifics.

studentdriver

If the TC is not locking, DO NOT go on any long highway trips. The transmission will overheat and burn itself up. I learned that through experience, unfortunately.

matrik

iTrader: (5)

I'm having the EXACT same problem, which i've been tryin to diagnose for 2 months now. I've replaced all solenoids, including the main wiring harness and tcc solenoid. And i just recently put in a new converter, swapped from a Racing Edge 3800 to a Vig 3200, and have the same problem. I had it tuned as well, so its not something PCM related.

matrik

iTrader: (5)

I just called the guys at PI, and they said something about when the car is cold its in closed loop, and when it warms up, something is making it run in open loop and not allowing the converter to lock, so it sounds like something is wrong with the tuning. Didn't really make sense to me, what do you think?

94strokedz

iTrader: (1)

Good point about closed and open loop. I hooked the Tech II up to it, monitoring closed and open while monitoring the TCC solenoid, and unfortunately closed to open made no change. The solenoid is still firing for the lockup, it just isn't physically locking. I'm gonna look into the Oring on the input shaft now. Thanks for the help.

94strokedz

iTrader: (1)

Well then grandma, next time we go to the strip, you'll have to show me how its done.

matrik

iTrader: (5)

Yeah, i ran a log with autotap, and the solenoid was still firing and the tcc pwm solenoid was changing percents from 0-99% like its supposed to. I'm going to check the O-ring and my vavle body, keep me updated if you find your problem.