1988 Cargo Van 4x4

When my van cold starts, it cranks for several seconds before firing. If you give it gas, it starts. Once it fires, you have to keep giving it gas, or start driving to keep it running. If you don't keep it revved up, it runs rough at a low RPM and might even quit.

Of course, all this goes away once the engine is warm.

After using the search function, it sounds like I might need to clean my cold start injector, or possibly buy a new one?

What should be my first course of action in troubleshooting this problem? Planning to tackle it this weekend.