Im working on my trans tuning right now, and when I get my TCC lock up set how I want it, it works for a while, then may, or may not work. It will lock up when forced through the HPT scanner, and sometimes it will work by itself, but others it wont. Where should I start looking? Is it something mechanical, or in the tune??

 

Converter lockup is controled by the vehicles computer. You have a tuning issue. You might do a search on computer lockup since it is a common problem.

 

 

Most likely intermittent misfires.

 

Thats what I was thiniking, but I cant see any missfires (actually someone a little more knowlegeable was watching the scanner) I went ahead and maxed out all my misfire code picker uppers (I m not sure what they are called) and plan to flash that tune in the morning. What gets me is that when I make any change and reflash the PCM, it works for a little while perfectly, but after a few miles, it just quits locking up.

Any help finding where to go in HPT to fix this??

Thanks for the help

 

it is easier to just raise the "misfire detection" temp to something like 250 rather than change those tables. I would also change the 1870 code detection temp to something really high to help diagnose it. I dont know why but i have seen cars do this all day...nothing works and then the next day after cooling off, it works perfect....weird but true

 

You can log the TCC Mode and look at whether it says
"locked" or something else (HPTuners displays a -3- in
the case that TCC lock MPH/TPS is met, but lock is
being suppressed for other reasons).

The other problem I've had, is a converter clutch that
is just not strong enough (combination of friction mat'l,
clutch diameter and line pressure as-applied through the
PCS and TCC solenoid valves). This manifests as holding
at very light pedal but "flaring out" under more throttle,
not an unlock per se. If you see this ("Locked" mode,
slip = 0 at (say) 10% TPS but hundreds of RPM at 20%
or like that, you may have to play with the pressure.
The delivered pressure at the business end of things is
pretty dependent on the fluid temp, hot = slip = hotter
in my experience.