Problems all summer long

It all started towards the end of April when I put my boat in the water for the first time this summer. My boat is a 2003 supra launch ssv with the inmar 325 assault TBI engine. I checked the oil before I put the boat in the water and it was good. Afte the boat warmed up I was checking over everything and checked the oil once again and noticed it now had water in it. Well long story short on that part was I had the engine replaced because of a cracked cylinder. (Dropped off in april and picked it up around the end of may.)

Ever since the engine has been replaced and this was occuring during the break in of the new engine I notified the dealer that installed the engine that it was having a hard to start problem. Also another problem where when you would return to neutral the rpms would drop to around 200 or 300 and almost stall and other times it would stall. I had none of these issues before the engine was replaced. They first said it was the fuel filter and changed that. The problem still occured after that was replaced. (Sometime in May)

Now it is july and the problem is still here and now that said my fuel was bad. So they drained the tank and filled with new gas. Long story short the problem was still there. (July)

Now still July and I took it back with teh same problem and they said the computer was showing codes (81)Inj A low/open and (81) Inj B Low/open. Said they contacted indmar and they said inj driver was bad and ecm needed replacement. They replaced the ecm and it did not correct the problem so they put the original ecm back in. Now with the original ECM back in they said it was the map sensor. They replaced that at my cost and it did not correct the problem. (Picked it up beginning of august)

Took the boat back after the weekend with the same problems and the sent some run files to indmar this time. According to an email from indmar and info from the tech that it is normal for engine rpms to drop when returning to neutral. The tech at teh dealer said they found erratic issue with ignition circuit and IAC valve wanting to stay closed not allowing idle air to bypass causing the hard to start problem. THe replace the ignition key switch and the IAC valve and Im still having the same problem.

My boat never did this before they replaced the engine and for Indmar to tell them it is normal for the engine rpms to drop that low is ridiculous. You boat should not stall out just because you are returning to neutral. Im not going to mention the dealers name at this time but am looking for advice on what my next step should be. As of right now I am in this about $7,150.00.