1996 Dancer won't start

[sotaman]

I am perplexed! My boat is a 1996 Sundancer with a single Merc 7.4 EFI bravo 3.To make a looooong story short. I had a mechanic whom I have used many times replace the gimbal housing. The engine had to come out. After I got her back, she ran ok, but on one particular day she was running at about 3300 RPM when she just dropped to under 1000 RPM. I put her in neutral and the idle was jumping like I was revving the engine. I took her back and had the fuel regulator replaced. Now she won't start at all unless I spray ether into the flame arrestor. I have a new VST tank, have cleaned the injectors and a new IAC sensor. My mechanic is telling me the fuel pressure is fine and there is a spark at the plug. Once started it runs OK, but it will not start without the ether..period! All other codes are clear. Any opinions?

 

[Asureyez]

Considering there are no fuel leaks on the suction side, let's think what ether does. It is a gas compressed to a liquid. As a liquid it has such low vapor pressure it turns to a gas at tempertures in the "Life Zone" and that gas mixed with O2 is explosive.

So we won't start without a explosive gas boost but we have gasoline present, but will run fine once started on ether.

So lets talk about air leaks on the suction side of the fuel delivery system. My money is on a chaffed line, or cross threaded compression nut. But that's just me

 

[sotaman]

If we have air leak on suction side, there would notbe correct fuel pressure on the fuel rail, no?