If your injectors are injecting fuel when you turn the ignition on, there's something seriously wrong. What makes you think that it's injecting? The fuel pump shouldn't stay running, either. You may have a short somewhere. You may want to check your test connector. There's a lead on there that would cause the fuel pump to run if it's ground. You may also want to check the fuel pump relay under the seat. It may be fused or something.
It's probably best, though, that you take it in to the dealer. I know it defies everything we believe in, but sometimes it's just the best thing to do.
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351W 89 Mustang GT Convertible