1986 Mazda RX7 DIENG

After I start the it reves up and than it dies. But if you keep the foot on the accelartor and keep it at about 25oo rpm it will stay running. As soon as I let go of the pedeal it will die. I was thinking it is timming or a egr problem but I am not sure. So please it would be greatly appreciated if you could asnser this question. It sounds like it is a commmon problem because I saaw another car online wich was doing the same thing.

thanks