Smokin Sunsetter

[SFD]

Looking for mechanical help...

Had the boat out on vacation for 9 days, it ran great the whole time until the wife took it back to the cabin on the last night. She said it died on her and she had to row it in. I looked at it the next morning and the only way to get it to start was to remove the spark arrestor and with a full throttle it would start. It labored to stay running and alot of white smoke and a hint of black smoke bellowed from the exhaust. She did not get a look at the temperature guage when it died on her as she was concerned about getting to the dock.

While running the next morning the oil pressure was 40psi and no block leaks or any other obvious things stood out, the temperature stood normal during the labored & smoking idle.

Subject:

1995 Sunsetter

Chevy 350 Magnum / EFI throttle body

276 hours, well maintained

Items checked:

Oil - changed 15 hours ago, no sign of water but seems like it produced about a 1/2 a quart.

Gas - no water is noticed in the gas.

Spark - coil is putting out 12.4 and cap & rotor appear clean & ok.

Plugs - # 1 & 2 are ok # 2 had a little black, 3,4,5,6,7 & 8 - wet with gas & black, no sign of water drops on the plugs.

Throttle body - Appeared to alternately spray correctly when running last ( when smoking )

Sounds - No knocking or clinking or clanking, just alot of skoke and labored running - like only a couple cylinders were firing.

Not sure if these are a symptom of a blown engine, burnt pistons, head gaskets or a manifold leak, the wet plugs push me toward spark issue but the smoke doesn't go with that, not sure.

I was going to do a compression check tomorrow for a start to see what each cylinder is doing before moving back to the cap & rotor

Anything else??

Any help is greatly appreciated...

Thanks.

Steve

[skier92]

Does the oil smell of gasoline? Perhaps leaky injector? If your positive there is more fluid in the crankcase than before, and it is not water, it has to be gas.

[MalibuBoats]

I would check your raw water impeller to make sure it is good. and that would most likely cause your over heat and rule out if the motor got hot. I have found that seaverly boat that i have worked on have had water in the tank. I had one yesterday that had 10 -15 gal of water in the tank till i pumped it out i just was clear and did not have any gas in it. that has been cause lots of problem like no power wont run and more double check the water in fuel

[Sunsetter95]

I agree to check the impeller to rule it out and any overheating. She would have heard the overheat alarm go off anyway.

Pull all the plugs and perform the compression test. I had a blown head gasket which caused a lot of spark knock and smoke. Make sure you unplug the ignition so no spark ignites fuel vapor coming out of the cylinders. Also, bring number one up to top dead center and check where the timing mark is. It is possible the timing chain jumped a tooth if it is worn out.

Check for water in the fuel. Drain some into a clear glass jar and hold it up to a light. If there is some there you won't miss it.

Check the fuel filters, the fuel pump pressure, and the fuel pressure regulator.

Do you have good spark? Coil or Ignition module issues.

That is about all I can think of.

[Baddog]

The fact that you could only get it started the next day by giving it full throttle, as you would with a flooded engine, leads me to believe you may have a bad engine coolant temperature sensor. Happened to me, but was really easy to fix. This is a $20-$30 part and takes 7 minutes to change, if you stop for a beer in the middle. When mine failed it was basically sending a signal to the computer that the engine was stone cold, when in fact it was warmed up to 160F, normal temp. Because the computer thought it was cold it enriched the fuel/air mixture to the point of flooding the cylinders and producing a lot of whiteish, blackish smoke. Changed the sensor and life has been good since.

[XTI04]

If the oil smells like gas CHANGE THE OIL!!!

[sparkoft]

White smoke would indicate oil. check the oil and make sure that there in not any water in the oil. then do a compression check on all cylinders. if it did overheat you could have a blown head gasket.

[SFD]

I agree to check the impeller to rule it out and any overheating. She would have heard the overheat alarm go off anyway.

Pull all the plugs and perform the compression test. I had a blown head gasket which caused a lot of spark knock and smoke. Make sure you unplug the ignition so no spark ignites fuel vapor coming out of the cylinders. Also, bring number one up to top dead center and check where the timing mark is. It is possible the timing chain jumped a tooth if it is worn out.

Check for water in the fuel. Drain some into a clear glass jar and hold it up to a light. If there is some there you won't miss it.

Check the fuel filters, the fuel pump pressure, and the fuel pressure regulator.

Do you have good spark? Coil or Ignition module issues.

That is about all I can think of.

We pulled the plugs, the throttle body kept sending fuel to the cylinders, I disconnected the fuel line from the tank and the plug to the seperator tank and the plugs to the injectors. There was a large amount of fuel that spit out of the # 6 cylinder ( about 4-6+ ounces ) when we turned it over to clear the cylinders while all the others had normal vapor coming out, # 6 kept spitting alot. We turned it over to get the raw fuel out and did two compression checks, one reading anywhere from 160 to 170 and the second round from 200 to 210. This seems incorrect as the manual calls out 150. The amount of fuel also seems wrong. I am doing a leak down test tomorrow to determine if whats going on with each cylinder. I guess checking the temperature sensors would be next. Coil puts out 12.4 + / -.

Where did your head gasket let loose? My guess is at the # 6 cylinder area, seems like a weak area with all the castings. Hoping for a head gasket or bad valve at the worst.

Guys, Thanks for any advice....

Edited August 12, 2009 by SFD

[skier92]

Not a head gasket issue. Fuel issue. And yes, Change the oil. Gas in the cylinder will make its way down into oil. Change before running engine at all.

[sparkoft]

is this a fuel injected engine? if you are getting that much fuel out of the number 6 hole you might have an injector stuck open. 4 to 6 ounces could break a piston.

Edited August 12, 2009 by sparkoft

[skier92]

If I understood the info in your original post, the engine has Throttle Body Injection (TBI) (two injectors in the throttle body) Yes? Sounds like one of the injectors is sticking open. A faulty Engine Temp. Sensor can cause excessive fuel delivery, but this seems like a lot of fuel and something that happened all at once. Change the oil, start and run engine for short period with hose for engine cooling (If out of water) Shut down engine and watch for leaking fuel injector. (Have a wet rag at hand in case of back fire through Throttle Body) Other than that, I'm not sure what to test next.

[electricjohn]

If only one cylinder has gas in it, then is does sound like a sticking injector, but it must be happening after engine shutdown. The injector is leaking till fuel pressure falls off, and the fuel pours into any cylinder whos intake valve is open.

[Faceplant409]

If it's a throttle body would the gas run to the easiest cyl to get to from the manifold? Might # 6 be closest or most direct route for liquid to run?

[nuttyskier2002]

Looking for mechanical help...

Had the boat out on vacation for 9 days, it ran great the whole time until the wife took it back to the cabin on the last night. She said it died on her and she had to row it in. I looked at it the next morning and the only way to get it to start was to remove the spark arrestor and with a full throttle it would start. It labored to stay running and alot of white smoke and a hint of black smoke bellowed from the exhaust. She did not get a look at the temperature guage when it died on her as she was concerned about getting to the dock.

While running the next morning the oil pressure was 40psi and no block leaks or any other obvious things stood out, the temperature stood normal during the labored & smoking idle.

Subject:

1995 Sunsetter

Chevy 350 Magnum / EFI throttle body

276 hours, well maintained

Items checked:

Oil - changed 15 hours ago, no sign of water but seems like it produced about a 1/2 a quart.

Gas - no water is noticed in the gas.

Spark - coil is putting out 12.4 and cap & rotor appear clean & ok.

Plugs - # 1 & 2 are ok # 2 had a little black, 3,4,5,6,7 & 8 - wet with gas & black, no sign of water drops on the plugs.

Throttle body - Appeared to alternately spray correctly when running last ( when smoking )

Sounds - No knocking or clinking or clanking, just alot of skoke and labored running - like only a couple cylinders were firing.

Not sure if these are a symptom of a blown engine, burnt pistons, head gaskets or a manifold leak, the wet plugs push me toward spark issue but the smoke doesn't go with that, not sure.

I was going to do a compression check tomorrow for a start to see what each cylinder is doing before moving back to the cap & rotor

Anything else??

Any help is greatly appreciated...

Thanks.

Steve

With the flame arrestor off and engine running can you see one injector spray more fuel than the other?

[Sunsetter95]

I agree to check the impeller to rule it out and any overheating. She would have heard the overheat alarm go off anyway.

Pull all the plugs and perform the compression test. I had a blown head gasket which caused a lot of spark knock and smoke. Make sure you unplug the ignition so no spark ignites fuel vapor coming out of the cylinders. Also, bring number one up to top dead center and check where the timing mark is. It is possible the timing chain jumped a tooth if it is worn out.

Check for water in the fuel. Drain some into a clear glass jar and hold it up to a light. If there is some there you won't miss it.

Check the fuel filters, the fuel pump pressure, and the fuel pressure regulator.

Do you have good spark? Coil or Ignition module issues.

That is about all I can think of.

We pulled the plugs, the throttle body kept sending fuel to the cylinders, I disconnected the fuel line from the tank and the plug to the seperator tank and the plugs to the injectors. There was a large amount of fuel that spit out of the # 6 cylinder ( about 4-6+ ounces ) when we turned it over to clear the cylinders while all the others had normal vapor coming out, # 6 kept spitting alot. We turned it over to get the raw fuel out and did two compression checks, one reading anywhere from 160 to 170 and the second round from 200 to 210. This seems incorrect as the manual calls out 150. The amount of fuel also seems wrong. I am doing a leak down test tomorrow to determine if whats going on with each cylinder. I guess checking the temperature sensors would be next. Coil puts out 12.4 + / -.

Where did your head gasket let loose? My guess is at the # 6 cylinder area, seems like a weak area with all the castings. Hoping for a head gasket or bad valve at the worst.

Guys, Thanks for any advice....

Between 4 and 6. I for sure lost the impeller and it over heated big time.

The previous members have a good point about a stuck injector in the throttle body. Also, a sensor is cheap to try.

Are the injectors replaceable in the throttle body?

For sure, change out the oil and filter. Look for any water in it.

Sure that was all gas that came out of no. 6? Maybe you have some water mixed in there. If you pursue the head gasket blown idea, disconnect the power to the fuel pump, assuming you have an electric pump, with the plugs out and ignition disconnected, turn it over to dry out the cylinders. Leave it open and perform the compression test the next day. Your high measurements do seem high. Excess fluid in the rings can give you higher readings, but that is still high.

Even with the high readings, were they fairly even across all of them. When my head gasket was blown, I could easily hear air leaking out the carb and the next cylinder spark plug hole.

[SFD]

Looking for mechanical help...

Had the boat out on vacation for 9 days, it ran great the whole time until the wife took it back to the cabin on the last night. She said it died on her and she had to row it in. I looked at it the next morning and the only way to get it to start was to remove the spark arrestor and with a full throttle it would start. It labored to stay running and alot of white smoke and a hint of black smoke bellowed from the exhaust. She did not get a look at the temperature guage when it died on her as she was concerned about getting to the dock.

While running the next morning the oil pressure was 40psi and no block leaks or any other obvious things stood out, the temperature stood normal during the labored & smoking idle.

Subject:

1995 Sunsetter

Chevy 350 Magnum / EFI throttle body

276 hours, well maintained

Items checked:

Oil - changed 15 hours ago, no sign of water but seems like it produced about a 1/2 a quart.

Gas - no water is noticed in the gas.

Spark - coil is putting out 12.4 and cap & rotor appear clean & ok.

Plugs - # 1 & 2 are ok # 2 had a little black, 3,4,5,6,7 & 8 - wet with gas & black, no sign of water drops on the plugs.

Throttle body - Appeared to alternately spray correctly when running last ( when smoking )

Sounds - No knocking or clinking or clanking, just alot of skoke and labored running - like only a couple cylinders were firing.

Not sure if these are a symptom of a blown engine, burnt pistons, head gaskets or a manifold leak, the wet plugs push me toward spark issue but the smoke doesn't go with that, not sure.

I was going to do a compression check tomorrow for a start to see what each cylinder is doing before moving back to the cap & rotor

Anything else??

Any help is greatly appreciated...

Thanks.

Steve

With the flame arrestor off and engine running can you see one injector spray more fuel than the other?

No they seemed normal, alternating pulses like they should.

[SFD]

If it's a throttle body would the gas run to the easiest cyl to get to from the manifold? Might # 6 be closest or most direct route for liquid to run?

# 5 & 6 - are driectly below the throats and the angle of the engine would put them at the most direct path.

[SFD]

If I understood the info in your original post, the engine has Throttle Body Injection (TBI) (two injectors in the throttle body) Yes? Sounds like one of the injectors is sticking open. A faulty Engine Temp. Sensor can cause excessive fuel delivery, but this seems like a lot of fuel and something that happened all at once. Change the oil, start and run engine for short period with hose for engine cooling (If out of water) Shut down engine and watch for leaking fuel injector. (Have a wet rag at hand in case of back fire through Throttle Body) Other than that, I'm not sure what to test next.

I'll try that, thanks.

[footnlongline]

Pull your exhaust manifolds and look in your exhaust ports for signs of rust, a possible breach in the manifolds will produce white smoke and eventually lead to severe damage from hydrolock. I have a 95 SS merc MPI, one of my manifolds rusted thru and now I have a new motor. It ran perfectly until failure.

[skier92]

Stay the course on the fuel issue first. That's the biggest problem (if not all of it)

[Baddog]

Pull your exhaust manifolds and look in your exhaust ports for signs of rust, a possible breach in the manifolds will produce white smoke and eventually lead to severe damage from hydrolock. I have a 95 SS merc MPI, one of my manifolds rusted thru and now I have a new motor. It ran perfectly until failure.

How exactly did that toast the engine?

[footnlongline]

Pull your exhaust manifolds and look in your exhaust ports for signs of rust, a possible breach in the manifolds will produce white smoke and eventually lead to severe damage from hydrolock. I have a 95 SS merc MPI, one of my manifolds rusted thru and now I have a new motor. It ran perfectly until failure.

How exactly did that toast the engine?

Hydrolocked it, bent a rod and scored the cylinder

[SFD]

Stay the course on the fuel issue first. That's the biggest problem (if not all of it)

AHH my grasshopper how smart you are.... While I did not have time to get deeper into the fix due to the kids football, I did get the boat repaired. by I found a new dealer while I was traveling for work one day. He was good find, charged by the job not the hour, honest & reasonable - how lucky was that? The problem was the VST tank. Some smegma was stuck in the needle, allowing more raw fuel that called for into the throttle body, thus - flooding her out. That explained the amount of fuel coming out of 5 & 6 cylinders. So lucky again, with the 280 hours she keeps ticking on. Unlucky part - winter is at the threshold here in Illinois so we don't have a whole lot of time left to enjoy this year out on the water.

Thanks for your advice, remember the cause.

Steve

[electricjohn]

What is a VST tank?

[Baddog]

What is a VST tank?

Heck, what's smegma (in a boat anyway)?