When driving in OD the under light throttle the converter acts like its locking and unlocking, the rpms on the tach only change 50-300rpm depending on the speed and load. Above 90K/hr (56mph) it works fine, locks and stays locked. I have tried adjusting the low rpm misfire table to 32767, but it still does it. And I checked the fluid level its fine.

so it does it below 90k/hr (56mph) or below 1500rpm.

light throttle, if I give it a bit more gas it will ether stay locked or unlock.

It cyclings, locked for 2-3 secs unlocks for 1-2 secs then locks again.

rpms go up higher with more load (hill or pulling trailer)


This is happening after 6.0L install and Trailblazer torque converter (11")

 

yeah mine does that also, its weird. maybe the transmission is on its way out?

 

Have you tried disabling the misfire code? When the PCM sees multiple misfires it wont let the verter lock up. Right now mine locks unlocks at random. Im assuming its because I havent killed the misfire code with Edit. I could be wrong guys, but I thought id give an idea.

 

I had the misfire code disabled, but the computer will still montor misfires it just won't set the code. Next thing I will try is changing the misfire detection temp.

 

Ah, ok I got ya man. TB verter still treating ya well?

 

Do you already have a shift kit in it ? What I think it is is the pwm working its magic ( I hate it). The Transgo HD shift kit is suppose to get rid of this by making the TCC lock up valve an on/off instead of the pwm ( pulse width modulated) factory setup if I'm not mistaken. This will probaly be my next mod if and when I can afford the time and money...Zed

 

storm hit the nail on the head. It's the converter doing exactly what you said ... unlocking and locking. It's actually called a partial lock, where the TCC selenoid is switching on and off.

The TransGo kit should fix that ... the high dollar one that is.