are all 6 injectors powered by 1 wire and where in fuse box does it connect in 1990 pontiac grand prix?
The injectors are powered at all times what makes the injector pulse is the ECU grounding the other wire out. If your looking for a fuse it should be marked EFI
Your best bet is to get a set of noid lights from your local auto zone you can rent them for about 30 bucks. this will tell you if your injectors are getting power and if they are pulsing the way they should be.
Looking for a Used Grand Prix in your area?
CarGurus has 2,860 nationwide Grand Prix listings starting at $1,995.
Search Pontiac Grand Prix Questions
Pontiac Grand Prix Experts