1989 f150 inline 6 runs good for a min and spit and sputter and dies

If it stays running if u press gas pedal then u have a vacuum leak if it still cuts off, fuel pressure test needs to be done

Second the fuel pressure checked 4 bad pump or filter I had that problem before after replacing fuel filter fuel pump coil turn out to be ignition module mine was on the side of distributor big plug on the side like this one I wasn't happy with the pip in the distributor either so I just bought a whole nother distributor are ignition module Maybe under hood on side above wheel well not sure what side she can troubleshoot it with a voltmeter or most part stores test them. Also check fuel pressure regulator for small gas leak u can try unplugging the water temperature sensor on the manifold and see if it runs longer. and while running unplug and plug back in the map senser just to see how it likes that not sure location on that model most likely on the back firewall or the side above one of the wheel wells. Id check the wires and plugs out too. If possible Id troubleshoot the ignition module and the pip senser first.