I purchased a 1990 GXL NA automatic to give to my daughter for her 16th birthday. Purchased with bad idle. Thought it would be simple. Lost $370 at dealer for diagnostics. Put in new Bypass Air Control Valve ($470). Have 6 volts AC at BAC connector w/10kohm resistor in place. BAC ohmed correctly. TPS's ohmed correct, checked TPS's with lights - OK. When I turn adjustment screw on ThrotBody for 1400 rpm starts seeking between 1000 and 1400. Stalls when put in drive. Runs the same with BAC plugged in or unplugged. What does screw under red cap on top of engine behind ThrotBody do? Car drives great speed. Tomorrow I'm supposed to tie a big bow to the car for the birthday part and its going to be a big dissapointment. Any help. Thanks!

 

i have a 90 vert auto and it didthis when i bought it i just adjusted the idol screw as hight as it could go the car nolonger dies when i put it in gear but will if i slam the breaks to a dead stop r put the ac on and try to stop.
this is a guess outta of the blue but mabe its the tranny r torque convertor cause my tranny is shot i am getting another with a torque convertor hopefully this will solve my problem till i get the $$$ to put a 5-speed in


hope u fix it


how many miles does it have?

 

76,000