Hooked up battery backwards.

I hooked up my battery backwards on my 1998 Mastercraft Sportstar. I fried the alternator which I replaced but now the engine cranks but the injectors do not spray fuel and the engine does not start. None of the fuses are bad at the ECM nor did the 50 amp breaker blow. I had a tech come out and test and he said that I need a new ECM. This doesn't add up to me. I would change the ECM out but Indmar doesn't have any more and the manufacturer stopped making them. I NEED HELP!!! I don't know if i should trust the tech that the ECM is fried and if it is what do I do now that they are no longer made?????

The good news is the MEFI ECU's really aren't manufacturer specific, the programming inside them is though. The easiest way if to find somebody with a known good unit and swap them. The next alternative would be to send it out for testing. Anybody that can test it should be able to hook you up with a compatible replacement as well as provide you a reasonable "tune" (program) for you specific engine.

Look at the ECU cover and see if it has the GM decal still on it. There should be a part number on it, starting with a 162xxxxxx, (those are the most common ones). That will tell you which flavor of MEFI is installed.

One other item - check the relays. many have diodes in them that wont tolerate the reversed polarity you may have exposed them to.