my 94 k1500 will start and run fine for a second then die out

i disconnected the vacuum line to the map sensor and pluged it and now it is running fine does this mean i need to replace the map sensor or could the problem be something else

Did you check for flash codes?... (33 or 34)

yes its not throwing any codes

Have you 'REMOVED' the EGR valve to see if it's partially stuck open? .. Especially if 4.3 (?) ...... IF you remove ONE of the injector connectors...run it on one injector... Does that help??