Gunk in Injector

[whiplash willy]

My car had been mis firing pretty bad, so I removed the Injectors to check them. The gas that came out of the fuel rail when I pulled them out was brown/orange color, and #3 &#4 injectors had brown gunk on the top of the Injector. The car is a shell I picked up a long time ago, and had been sitting for a while. I swapped my old SOHC in and put a new fuel filter in it, and ran about 3 tanks of gas through it. What could cause this gunk in my fuel system?

[rogoman]

Gasoline that's been sitting in the fuel tank for a long time starts to form varnish; condensation causes water to form in the tank which leads to rust. So now the gas has an orange appearance.

Drain the fuel tank. The fuel pump should be removed and cleaned. The fuel lines should be flushed out. The injectors should be removed and either cleaned or replaced.