1994 MerCruiser 3.0L I-L4 Will not start in water

[Kevins2011]

1994 MerCruiser 3.0L I-L4 : Saturday we were out at the river for the first time and the engine started great and ran really smooth before I turned it off. After 15 minutes I couldn't get the darn thing to start back up and we had to be towed in. I have opened the Exhaust to look at the Shutter Valve and all looks good (small opening at each side of valve with no back pressure). The Exhaust Bellows from the Transom to the Outdrive is brand new and there are no trim tabs on the boat. I hook it up in the driveway with the garden hose/ear mufffs and everything works great, but once it is in the water it will not start. What should I be looking for as my potential problem..?

 

[Howard Sterndrive]

Re: 1994 MerCruiser 3.0L I-L4 Will not start in water

start with a compression test of the engine

 

[04fxdwgi]

Re: 1994 MerCruiser 3.0L I-L4 Will not start in water

1994 MerCruiser 3.0L I-L4 : Saturday we were out at the river for the first time and the engine started great and ran really smooth before I turned it off. After 15 minutes I couldn't get the darn thing to start back up and we had to be towed in. I have opened the Exhaust to look at the Shutter Valve and all looks good (small opening at each side of valve with no back pressure). The Exhaust Bellows from the Transom to the Outdrive is brand new and there are no trim tabs on the boat. I hook it up in the driveway with the garden hose/ear mufffs and everything works great, but once it is in the water it will not start. What should I be looking for as my potential problem..?

When you say it "wouldn't start", do you imply she turned over fine, but wouldn't fire? Or wouldn't turn over?

Being on the garden hose vs: being in the water should make no difference, except maybe angle of boat made something move just right and caused a change in a ground or other connection or perhaps not pulling fuel.

Perhaps it's a "hot engine restart" issue vs: a cold engine start, or perhaps it flooded when trying to re-start a hot engine.

 

[Kevins2011]

Re: 1994 MerCruiser 3.0L I-L4 Will not start in water

Tested Compression "132 Avg"
Wouldn't Fire.. It would turn over just fine.
I was thinking about the boat being tilted lower in the rear and thinking that I may have water in the gas tank. The fuel pump works great but I have not tested for water in the gas.
Thanks... I will keep looking.

 

[thumpar]

Re: 1994 MerCruiser 3.0L I-L4 Will not start in water

Check for spark when it won't start. I would bet it is a hot start issue.

 

[Howard Sterndrive]

Re: 1994 MerCruiser 3.0L I-L4 Will not start in water

and look down the carb throat while trying to start it - see if fuel is there, choke open etc

also have a look at the shift interrupt switch - to make sure it isn't hanging or reacting to a bad lower shift cable
can unplug it to eliminate it too

 

[Kevins2011]

Re: 1994 MerCruiser 3.0L I-L4 Will not start in water

I apologize..
It has spark and turns over great when it is not in the water.
As soon as I put it in the water the system bogs down and will not start.
I am looking for water in the fuel tonight, to see if maybe I have water in my fuel tank.
Spark, compression, fuel to the carb is all great.

 

[Howard Sterndrive]

Re: 1994 MerCruiser 3.0L I-L4 Will not start in water

weird - failing riser gasket maybe? was there any water misting out the cylinders when doing the comp test?

 

[Don S]

Re: 1994 MerCruiser 3.0L I-L4 Will not start in water

Do you give it some throttle when starting in the water?