3.0 Mercruiser stalls when warm

[JWebber]

Re: 3.0 Mercruiser stalls when warm

Before yuo throw more money at it, I would test the fuel pump first. Got any fuel in the sight tube line to carb. (Clear tube running from fuel pump to carb vac port??)

 

[bds85466]

Re: 3.0 Mercruiser stalls when warm

boat has never run better. For 10 minutes! Then dies. A few minutes later it will run again, but only for a few minutes. What am I missing?!? I'm going to try a second gas can with a primer bulb attached before the fuel pump. My guess is if it runs while I pump the bulb, I need a new pump. Correct?

I'm not sure about that.

Is it still not able to go above idle after you restart it?

What kind of fuel pump do you have?

 

[strayliner]

Re: 3.0 Mercruiser stalls when warm

I don't think there's any fuel in the sight tube but it's yellowed over time. I'll replace the tube before I start it next time.

Fuel pump is a mechanical type that is attached to the starboard side of the motor. It has a fuel filter in a "bowl" on the bottom which I replaced. And yes, after resting a couple of minutes it will restart and only idle. If I anchor for 20 minutes or more it will restart and run at higher rpms for a couple of minutes and then repeat the cycle.

 

[GNIRWIN]

Re: 3.0 Mercruiser stalls when warm

i am having the exact same issue with a 2000 3 liter. I have owned the boat since new and this week while on vacation the third day of running the boat this started out of the blue. What you describe is the exact same symptoms I have.

 

[GNIRWIN]

Re: 3.0 Mercruiser stalls when warm

some observations I made: problems started about an hour after buying ten gallons of fuel at a marina, also an above 90 degree day that was also high on humidity. I was heading home when it started so I let the boat set until the next morning. I bought some fresh gas at my home marina where I know the gas is fresh, high test and has no alcahol. I also ran the engine compartment blower the entire day. The engine only sputtered once briefly after doing what I decribed above. I am wondering if I am not having some wires that are becoming old or not soundly connected and the humidity/heat inside the engine compartment caused the issues. I also noticed my depthfinder kept shutting off prior to the first day's problems but didn't the second day. I really don't think this was the fuel but I wanted to put down everything as it happened.

 

[CormacfARRELL]

Re: 3.0 Mercruiser stalls when warm

I am currently having a similar problem with my mercruiser 3.0 l , originally thought it was a fuel problem , but now I am fairly certain that the probllem is with the automatic choke.Check it out and let me know how you get on.

 

[jpecha]

Re: 3.0 Mercruiser stalls when warm

I am having the same problem with my 1998 Bayliner Capri, 3.0 Mercruiser. The fisrt time it happened, I was 20 miles across a 27 mile lake running approximately 3,500 rpm. The engine suddenly dies. It will start right back up, but will die if I take it over 1,300 RPM and gets progressively worse. Ended up being towed 7 miles. I thought I ran out of gas, so I filled the boat up (only took 16 gallons, so it was not empty). Proceeded to run 27 miles back across the lake with no problems. Took the boat to my mechanic. He checked for water in the fuel, There was none. Adjusted my carburator and got it back the next day only to go across the lake and 1/2 way back before the same thing happened. After 4 hours of limping across the lake, I ended up in the dark, calling 911 and towed by the local Onieda sheriff department (great guys). I have read the thread and can't wait to hear your solution.

 

[strayliner]

Re: 3.0 Mercruiser stalls when warm

Thanks to all for all suggestions. I have tried everything I know and replaced most of the electronic components. I gave up . . . the boat has been in the shop for two weeks. They are stumped! The shop has talked to Mercury and they are confused too. I will let you all know what they find out.

 

[DarrinT]

Re: 3.0 Mercruiser stalls when warm

Check the fuel lines especially in the tank(s)

Buddy of mine had the exact same symptoms and it turned out to be a crack in the line in the tank that would suck air under high fuel flow conditions stalling the engine. The crack would then close and it would start right up!!!!

Made him bonkers for two seasons before he found the flaw beacuse with a full tank the crack was under the fuel so this problem was only intermittent under the condition of lowish fuel and WOT

 

[joe casey]

Having same problem. Ever figure out what it was?

 

[GA_Boater]

Having same problem. Ever figure out what it was?

The OP left the building in 2010, 7 years ago. Please start a thread of your own

Closed.