I recently installed a PTC 4k lockup converter that i got from another member on this forum. He was local so before i got the converter I went for a ride in his car to verify that the converter did what it was suppose to and it did. I put it in my car and when my car is cold the converter locks up just fine, but after the car gets up to temp the converter will not stay locked. When I'm accelerating it locks up fine, but when I get to cruising speeds it unlocks. Any Help!!
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1999 Camaro Z28: (OEM SS Hood, Wing) Fast 90/90 w/Speed Inc Fuel Rails, 42lb. Injectors, FLT Level 5 Trans, PTC SS3800 Stall,T-Rex Cam, Dart 205cc Heads, Powerbond Underdrive Pulley, BMR Suspension w/UMI Tunnel Mount Torque Arm, Hooker Headers & Y-Pipe, Magnaflow Catback, TRE 255lph Intank Pump w/MSD 255lph Inline Pump, BMR 1.2" Lowering Springs, Drilled & Slotted Rotors, NOS
You have some low level of misfire detection (possibly
false, from loose / lightweight converter) that is inhibiting
the lockup. That's a fairly simple tune tweak, just double
the values anywhere they're "sane" in 6 or so misfire
tables. Probably only 1-2 of them have anything to do
with it, but I couldn't say which so I hit them all, on mine.
I had the same thing when my 10" 3500 went in, and lots
of people do.
Converter Lockup 
