Hi all!

I have my new 422 iron block installed.
I also did a be cool and a cooler thermostat.
I have the built FLP LEVEL IV tranny with vaccum modile for the shifts, since
three years now.

Now I have the problem that my Torque Converter doesn`t lock up most of the time.

My question:

Does the lock up somehow relate to coolant temps????
It really seems to me, it does.

I ask that because it`s very cold outside now and the be cool and thermostat
let the water go down to
154°F on the highway.....and the TC doesn`t lock up.

When I came home after 2 hours of no lock up, the last minute of driving I
had about 180°F water temp and the TC suddely locked up.

Also when I do a stop during highway driving, and the coolant gets warner,
then the TC does lock up for a while.....and it seems to me as soon as I get
on the highway again and the coolant goes back to 154°F the TC looses the
lock up again.

It will be warmer outside this weekend and getting warmer and warmer outside
and I also will put in a 180 thermostat instead of the 160°, but just wanted
to know if it can be that the measurements of the coolant temp. decides if
the TC does lock up or not......

BTW, my TC did never lock up the first few minutes after cold start when I had my stock
engine in, so it really may be it waits that the coolant has warmed up to get
the lockup.

And when I first drove my stroker Vette with the stock thermostat and hotter water temps, I didn´t recognise lock up problems.
I just recognised them after the thermostat install, but who knows, I may be wrong?!?!?


It sure is PCM related as I can lock up the TC with my lockup switch without
any problem.


Thanks in advance for your help!!!


Michael





[Modified by Austrian Vette, 9:35 PM 4/9/2003]

 

Michael is your car even going into closed loop at those low coolant temperatures? You want the engine to be at 160 at least, preferably more. With LS1 Edit you can adjust the TCC lock up based on MPH and % Throttle.

 

Godspeed,

yes it goes into closed loop.

But indeed the too cold water temps seem to cause my lock up problem.
I just read a post on LS1tech and it seems the PCM reads the temp sensor for operating temp bevore allowing a lock up.
That would declare why no lock up on the highway .....154° is too cold.

Hope that´s it because I LOVE to drive with the new engine and I need to drive it a lot to get the oil temperatures down (breaking it in).......
I only have 100 miles on it yet because it was snowing two days ago :(

But it should have 70° this weekend....then I go for a long drive.......

Michael

 

Michael,

According to my 98 service manual, TCC lockup is controlled by
transmission temp minimum of 64 degees F (18 C) and engine coolant
temperature of 140 F (60 C) which is pretty close to what you are seeing.

I 'll bet that once you get warmer weather (or a 180 thermostat) lockup
problems will be history...........


Dick

 

Thanks,

I hope you are right.

I´ll see this weekend......it´s getting warmer outside.

Thanks,
Michael

 

Problem solved!!!

I did desensise the misfire tables and the TC did lock up.

No chance to get that done with a 236/240 601/608 cam without desensising
the misfire tables.

:cheers: :cheers:

Michael

 

:iagree: with the temps.....That's why I have my service maunuals. Very easy to trouble shoot using Root Cause Analysis :thumbs: :cheers: