Why does my 1994 gmc sierra stall when i put it in gear

Your idle air controller may be failing. Begin checking for stored codes using a code reader, and progress to standard troubleshooting steps such as checking spark, fuel delivery, and operation of the intake air control circuit.

There are a numerous reasons for this problem..best bet is to have it serviced by a reputable indavidual

check fuel presure

yes i have an idea. you may have a bad idle control sensor. you have the symptoms of it. so far as you've posted. the sensor cost's about $20.00 ONLY 2 SCREWS to replace and any parts store that you purchase it from can tell you where it's located on your engine.usually on top of engine,silver canister type w/one plug in[electrical] also when replacing,disconnect the positive cable on your battery, this allows the computer to adapt the new component to the system. if there is anything else i can assist you with,please repost your question to fixya.com there are plenty of nice people out there that will be happy to [assist] you. thank you for choosing fixya.com

i donthink it is pickup coil....i think u need to replace eletric ignition down on steering colum

i have a 06 sierra that done the same thing and it was the distributer gear stripped

have him check the catalytic converter it sounds like it is glogged

i would check the dist.cap and wires.this seems to be a place to start.check all vacum lines.would also check fuel pump pressure.you need to determine if its fuel or elect.may also consider cam sensor.

had this problem on my neighbors 98 chevy truck with the same engine !!
it turnd out too be the fuel pressure regulator,you have too pull the upper intake too replace it!!

check your pmd switch. i had mine changed and it runs great. the problem is that it gets too hot and burns it up. be sure to move the pmd swith on the firewall away from the injection pump.