White smoke/steam and fuel in exhaust

milan

Cadet
Joined
Feb 17, 2010
Messages
14
Hi all,
I have a 2002 6.2L MPI with a Bravo I. The last two times out I had a problem that exactly repeated. I'll try to make this as short but thorough as I can.

I was out running around, boat working great for hours. Come in to port and idled down to 1000 RPM no problem. Pulled back into neutral and stalls out. Try to restart. Can't. I put it in the "clear flood mode" and it starts after long cranking. It won't idle and needs about half throttle to stay running. White smoke/steam coming from prop exhaust and smells bad of fuel. I went back to look at what's going on and fuel is clearly rising to the top of the water. I threw anchor and started trouble shooting. I put a fuel gauge on fuel rail. Turn key on and get fuel pump output of 42 PSI for 3 seconds and goes to 0. I do that several times. I am thinking maybe fuel regulator or stuck fuel injector. I go back to the engine and scratch my head. How can I check the fuel injectors while floating at sea? I thought...what if the ECM is telling the fuel injector/injectors to be open. The 2 ECM connectors were right there so I unplugged them with the intent of resetting/rebooting the computer. I turn the key on, the pumps runs with 42 PSI, stops and holds at around 35 PSI. I turn the key and it starts with no throttle required and performs great all the way back to the dock.

I was getting the Smart Craft alarm while it was malfunctioning and after disconnecting the connectors and it was running properly, the alarms stopped. I don't have a way of checking what alarm codes were flagged without taking it to a mechanic. I eagerly await feedback. Thanks.
 

kmarine

Chief Petty Officer
Joined
Nov 5, 2010
Messages
591
Re: White smoke/steam and fuel in exhaust

Try to read spark plugs and see if you have water getting into a cylander. Whille you are there try a compression or blow by test if available. The possibilities bad head gasket ,intake gasket, exhaust manifold, stuck valve etc. I believe you can use a automotive obdII on your boat but am not sure.
 

wire2

Lieutenant Commander
Joined
Jun 25, 2007
Messages
1,584
Re: White smoke/steam and fuel in exhaust

.....

I was out running around, .....
Does your wife know?:D

Is there no provision with that PCM to display a code on the check engine light?
Like on some cars, where you turn the key to "on" 3 times, then count flashes?
 

ENSIGN

Lieutenant Junior Grade
Joined
Jun 21, 2009
Messages
1,179
Re: White smoke/steam and fuel in exhaust

start with the basics,check the compression !
 

sqbtr

Senior Chief Petty Officer
Joined
Feb 23, 2010
Messages
716
Re: White smoke/steam and fuel in exhaust

I would do a quick check of the injector harness, possably a chafed wire touching ground intermittenly.

The ECU sends poss voltage to inj all the time and switches the ground to trigger the injectors.
 

milan

Cadet
Joined
Feb 17, 2010
Messages
14
Re: White smoke/steam and fuel in exhaust

Thanks for your replies. I have not checked compression but I don't suspect it to be bad. This is a problem that turned on and back to normal like a light switch. Can a TPS sensor tell the computer to dump fuel when at idle position? Could the computer have malfunctioned holding an injector open? I tried several times to restart with the same result until I unplugged the two computer connectors and it started right up without doing the "clear flood" procedure. and ran perfect. There was so much fuel coming out of the exhaust it made the water look like it was milky and after turning the engine off fuel was still separating from the water and floating to the surface 40 to 60 seconds later. Like I said, just as soon as I unplugged the computer, Shuzaam! ran like a top.
Does Don have any ideas?

P.S. I'll check the injector wire harness. Good info to know that the ground is being switched.

Thanks.
 

kmarine

Chief Petty Officer
Joined
Nov 5, 2010
Messages
591
Re: White smoke/steam and fuel in exhaust

I agree with going through all connectors with contact claner. I have had many mysterious sensor problems corrected this way. Bilge areas are moisture prone by nature. Corrosion is a constant battle.:)
 

milan

Cadet
Joined
Feb 17, 2010
Messages
14
Re: White smoke/steam and fuel in exhaust

I checked my connections. They all look perfect. They have rubber seals to keep out moisture. Has anybody had fuel come out the exhaust before and if so, what was the problem?
 

magster65

Commander
Joined
Sep 1, 2002
Messages
2,573
Re: White smoke/steam and fuel in exhaust

I checked my connections. They all look perfect. They have rubber seals to keep out moisture. Has anybody had fuel come out the exhaust before and if so, what was the problem?


Just a thought... the fuel cooler on mpi's is aluminum. They corrode and... have symptoms like you have.
Google it, there's info on it.
 

milan

Cadet
Joined
Feb 17, 2010
Messages
14
Re: White smoke/steam and fuel in exhaust

I'll check. I flush real good every time I put it in salt. Does this only happen to boats that stay in the salt all the time?
 

magster65

Commander
Joined
Sep 1, 2002
Messages
2,573
Re: White smoke/steam and fuel in exhaust

I'll check. I flush real good every time I put it in salt. Does this only happen to boats that stay in the salt all the time?


I would think the salt is a little harder on them than fresh but I don't know. Just learned of this myself.
 
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