93 Suburban dies when running idle and is hard to start

[dirty dan]

Is this an ALDL system? If so, are you getting a code 12?
Start with the basics. Have you checked your vacuum lines, especially to the MAP sensor. Have you checked to see if your ECM fuses ('91 has two, not sure about your's) and/or crank fuse is good. It appears to be TBI from your post. Check to see if your wires to your injectors are grounding at the air filter housing). Check your ECM grounds (on '91 @ intake, thermostat housing RH bolt. What's the IAC count when you turn on your key?

[Bremln]

Sorry I never posted the solution. It turns out the ignition module was faulty. I took it in to O'Reilly's and they tested it for me. It only occasionally failed, but as soon as it was replaced, the suburban ran fine.