3spd auto help

i bought an 86 2m4 while back, it had sat for a year. When i bought it it had no front brakes, i ran new lines and installed callipers. I then took it on the highway for the first time(I had driven it in town with only back brakes. ) the first time on the highway it drove smooth and when i slowed down for the light it died. I then restarted it and when i put in in drive it died. I then put it in neutral and droped it doing 2k it went sluggishly but it went, then it drove fine. the next time I took it on the highway it did it again, and again, and again, everytime i go on the highway it kills it when i come to a stop. I tried driving it like a stick while decellerating, but the problem remained, it also does this with reverse, if the light is green adn you dont have to stop after you get off the highway, it will just die the next time you slow down to less than 5mph. Is there any reason for this, or a solution????

matt holt,

[email protected]

The purple wire on the brake light switch runs the TCC (torque convertor clutch) and it appears that your TCC is staying engaged all the time.Thus running like a std trans 1:1 ratio. The TCC switch or sometimes it's called a Lock up switch may be bad too. Both of these are easy fixes, even tho the TCC Lock up switch is in the tranny it can be done w/o removal of the tranny. But if it's the Convertor it will have to come out. More than likely tho it's the brake ligt switch. When your driving at 50 mph , lightly touch the brake pedal, if you see a increase in the rpm's the lock out (TCC) is working if no increase Bad TCC or Brakelight switch. Remember its the purple wire off the B/L switch. Also of you have a volt meter hook it to the purple wire and if you see voltage through the wire when you touch the brake (at 50/55mph) then it is the Lock up switch. B/L switch 15 bucks..Lock up switch....30 +/- good luck just had the same problem and I almost went nuts trying to find the problem

More than likely tho it's the brake light switch.

Sitting is bad for automatic transmissions... it is possible the tcc clutch valve opened and stuck there... the only remedy for this is to rebuild the valve body. That would be on the extreme side though, check the electrical first. See if your brake lights work... A bad ground in the brake lights might cause the same tcc problem as a bad switch at the pedal. Usually the high-mount light will turn on if the switch is good but the tailights won't.(2 seperate ground wires) Grounding issues make cars do weird things... mine had a bad ground wire in the tailight harness and prior to fixing it If I stepped on the brakes with the key off all the warning lights would come on, the ashtrays would light up and the fuel pump would start running!!!!!

For what it's worth, mine did the exact same thing when it got hot and it needed a new lock-up switch.