I double checked the serial number of the engine with the module. I checked the old module and followed the supercessions. I found the bullentin discussing this and they all confirmed that the 21242092 ECM was the correct one.
My belief is that he had a faulty fuel injection pump. On our web site we have a couple of blogs and newsletters discussing these pumps.
They are made by Carter for Volvo Penta and the two companies have been blaming each other for the problems for years. They finally have come up with a pump that seems to work well 21608511 and the pumps come with a year warranty.
Before they did come up with this new pump they had gone through 4 version of this pump and last year I probably sold 250 of them.
The symptoms of a faulty pump can be all over the map, but below are some of them:
1) A high pitched screaming
2) Rough running engine sometimes at high RPM or some times only at low RPM or sometimes at both.
3) The engine will run perfectly then stop.
4) The engine will overheat and then not overheat.
5) A funny smell of gas in the exhaust.