Engine issues 5.7

[FriDaz293]

I have a mercruiser 5.7 efi and i am having engine issues that no mechanic has be able to fix. Last year the engine would cold start fine and run fine but if it was at running temp and you shut it off it would run rich and at high rpm at idle. It progressively got worse until it ran rich and idles high all the time and sounded like a big vacuum leak was happening. 1st mechanic said it was out of time and that the distributor was loose and he fixed it and set it back into time. That worked for a day and then started again and had him come back out and said my distributor was bad and replaced it. Still happened and called another mechanic and they said it had big vacuum leaks from the intake manifold and carburetor manifold gaskets which they fixed and did the still same thing happened. Mechanic number 2 came back out and said my thermostat was bad my coolant temperature sensors were bad my map sensor was bad and my TPS sensor was bad. Nothing changed. They then said it was out of time 180 and set time again which didn't help. Now engine doesn't start and mechanic 2 says put a engine in. Mechanic 3 says ECU maybe and engine looks ok with 130lbs of compression. Anyone have any ideas getting frustrated at having people just throw parts and give me a bill and nothing changes or things get worse.

[Kate]

". . . running temp and you shut it off it . . ."

Did it restart per normal? Is the fuel pump external or internal to the tank? If external and hard to start when hot, you might check for "heat soak."

[FriDaz293]

Right now it cranks but won't start. The fuel pump is external under the engine. It's tbi injected and the injectors are spraying with good flow. It's acting now like it's way out of time.