94gmc Sierra 4.3 dies at idle changed fuel
pump cap rotor has good spark have to put a
cap of gas in tbi to start but if not reving will
die runs fine when driving just start up and
Have you checked the idle air control valve?? They are notoriously bad. If your idle air control valve checks out (meaning, it's good), then it could likely be EGR valve. However based on what you're describing, it is not likely that EGR is your problem.
Search GMC Sierra 1500 Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
GMC Sierra 1500 Experts