I don't know that it is necessarily a no brainer to junk the car. The injector failure risk was a risk you were already assuming before the engine failed, so it was a risk you were already comfortable with, presumably. I don't think that should factor into your decision. You claim the car is in generally good condition, other than this engine failure. I think the question I'd first ask you is this: before the engine failed, how long were you planning on keeping this car? If you had planned to junk it in the next year or two, then I think the smart thing to do would be to accelerate your timetable and replace it now. You probably wont get your $3K back from in in a year or two, and you're still assuming the injector risk at the same time.

If you didn't have any plans to junk the car, and you really believe that mechanically it can give you another 5 years, then make the investment and fix the car. You'll get your money back if you amortize it over those 5 years. The hard truth is that you car, with a good engine, is probably only worth $3K if you were to sell it so that repair doesn't seem to make sense on its face. But it is worth $14K to you, because that is what you are prepared to spend to replace it. If you can drive it enough to get that $3K back, then spend the money.