Question on TC Lockup with 94 454

[kevinvinv]

Hello,

My Tune has been running fantastic but recently what I thought was some "hunting" or "hesitation" mid-throttle turned out to be the TCC sort of locking and un locking and in general doing nothing super positive.

It will lock solid later (at higher speeds) or if I back of the gas -- and if I punch it- it will quit trying to lock... so overall it is good at the extremes but the middle ground has gotten squishy.

I am running a 454 with a 4L60E tranny so a little extra torque on the front end. The tranny is build strong and the TC is supposedly pretty good... but I am wondering if this is an indication of a tune issue / sensor issue or if maybe some failure of the TCC might be happening.

Any thoughts welcome.

Also, if anyone is interested- I have a 91 454 MEMCAL available if anyone wants to make an offer. Cheap is OK.

KV.

[lionelhutz]

Pull-up the TCC tables and see if there is anything obvious that would cause it.

The transmission tables are all similar. Basically, you will find tables and from those tables you can find that at any particular speed there is a lock and unlock %TPS value. What happens is that if the %TPS goes below the lock value then it locks. If the %TPS goes above the unlock value then it unlocks. Anytime the %TPS is between the 2 values it stays in the same condition it was in. So, the lock has to be lower then the unlock and you need some difference between them to avoid hunting.