83 Eldorado, Starts fine, no idle

I have an 83 Eldorado. Just had new sparkplugs & wires, new distributor & rotor button, new battery, and a new altinator installed, but I can't get it to idle. It starts fine. I can pat the gas pedal and it will stay running. But once I stop patting the gas pedal, it will die. I've even had it pressed half way to the floor and held it there and it will die. Just will not stay running. Soon as it dies, I can start it right back up no problem. I have no clue what the problem is. Any help or advice would be most appreciated.

Fuel pressure is one issue, if it won't idle the isc could be another, additional diagnostics must be done, there is no quick answer for this.