caidek

It's a 86 GXL auto with 155k that I looked at. Once running it rev's to warmup then drops to slightly below 800rpm. I didn't notice any white smoke while revving it to 3-4k. I got out and let it run for awhile. It seemed to be fine once it starts.
The engine bay looked pretty clean, no dents or major rust.

I'm thinking low compression or dirty injectors. Anyone know what's wrong with it?

DerangedHermit

At 155k I would guess it probably has both. I know low compression causes slow starting, not sure about dirty injectors.

MPM

Check your plugs also. All the general tune up items need checked. Clogged fuel filter or air filter can cause hard start also.