Motor dies when I give it gas

[pensacola]

I have a 1999 Mercruiser 5.0 305 engine. It starts fine, will idle for a little while then die. I can give it some throttle at first, it will rev up two or three times, then die. I have already replaced the fuel pump and water separator, fuel filter and all those goodies. Now we cannot figure out why its doing this. Any help would be appreciated.

 

[Don S]

Re: Motor dies when I give it gas

will idle for a little while then die.

Bet that is in the 15 to 30 second range.

Sounds like the oil pressure switch for the electric fuel pump has either gone bad or one of the connections is bad.
Here's a wiring diagram of the system.

 

[pensacola]

Re: Motor dies when I give it gas

That already happened. A while back it was happening and you mentioned that. I replaced it and it fixed the problem. So this time I tried jumping it across to bypass it but still no go. It actually runs for more like about a minute. That was the first thing I tried this time, couldn't be that easy of course.

 

[Don S]

Re: Motor dies when I give it gas

Time to do some pressure tests on the fuel pump and see if it's keeping pressure up.
Have you checked the water seperating/fuel filter for water?
Could also be a problem with the boats fuel system.
http://forums.iboats.com/showthread.php?t=283269

 

[pensacola]

Re: Motor dies when I give it gas

Its a new fuel pump and water separator. But its been sitting for five months because of the broken starter mount problem. So I am kind of worried about the gas. Do you think some stabilizer would be good enough or will I have to drain the tank.

 

[Dryon]

Re: Motor dies when I give it gas

Fuel stabilizer will not bring bad gas back to life. It must be added to new gas to keep it fresh for extended storage.

 

[pensacola]

Re: Motor dies when I give it gas

I think its bad gas. We took the top off the carb and blew some air through the hole where the fuel line goes in. Then we connected a external tank of gas and its running good. Now I just have to drain the tank and should be fine. Thanks for the advice.