injectors not opening

Is there any ecu sensor that cause the injectors not to open. Injector resistor checks out.I'm getting power to the injectors.But Missing the {MAP]sensor. Missing the ground on the valve cover. Would any one of these problem cause the injectors not to open? Basic thing if any one knows all the cause for the injectors not to open I would like to know this informatoin please.

It say's in a manual i have that if the tranny ground, thermo ground and valve cover ground are not hooked up then then it will not run, but as far as how it all works as far as if a certain ground is missing then i am not sure what the symptoms would be, but it sounds like it would be a good idea to ground the valve cover.

well, ground the harness to the valve cover, which ever wires are to be grounded, not just ground the valve cover