vibrating and dying

i have a 95 cutlass supreme with a 3.1 in it. we recently did a lot of work starting with new head gaskets, got the heads milled, new intake gaskets and spark plugs plus some sensors. the problem is that it wants to die when i am sitting at a dead stop. it will start back up and run as long as it is getting gas. i also had new injectors put in it. i dont know if this could be caused by a bad ignition coil or plug wires. it also has a vibration at around 50 mph and up. the vibration i noticed is also there after it dies and i restart it, the vibration is at lower speeds. could this be a misfire from a bad coil or wire. any help is appreciated. also i check the site regularly so if u post something i may have another question for you so if u could also check this thread i would appreciate it. thanks for any help or advice anyone can give.

Maybe the crackshaft sensor. I saw similar problems in a Ciera with a 3300 although there was no viberation at high speeds. The engine just stalled whenever it wanted to. sometimes it would start right away and sometimes it won't.

Have you checked the timing?

if it ildes down and tries to stall when you come to a stop it is prolly a bad distance/speed sensor.