smell and smoke!

[eminentguy]

Hello

My 5.7 OSXI-GF GASOLINE PENTA engine is running just fine .. but I notice at startup sometimes some smoke and smell that I guess is nothing to do with oil burning as engine is 200 hours only and oil does not get less.
I also guess the fuel consumption is high.

I suspect this is to do with injectors, do you think so? What would be possible other reasons?
If injectors, can they be tuned or cleaned? Or replacement is best option available?

This boat was left on water for so long before I bought and fixed it. Maybe this could be a reason? I did 100 hours already using it by now.

Thanks...

Firas

 

[dypcdiver]

Re: smell and smoke!

Could just be running rich i.e. as if it is choked for a cold start, but that is all adjusted by the control module. However if it continues when the engine is at normal running temperature, then you may need to look at the temperature sensor.

 

[DCinVA]

Re: smell and smoke!

There are 3 kinds of "smoke"
White smoke = steam (water)
Black smoke = fuel
Blue smoke = oil

What color smoke do you have?

 

[eminentguy]

Re: smell and smoke!

thanks guys ...to be honest am not sure yet, as this smoke suddenly comes out when am moving and so slight .. but the smell is very noticed actually.
I guess it could not be Oil as oil level is not never less... but the higher fuel consumption is something I noticed definitely...

 

[alldodge]

Re: smell and smoke!

thanks guys ...to be honest am not sure yet, as this smoke suddenly comes out when am moving and so slight .. but the smell is very noticed actually.
I guess it could not be Oil as oil level is not never less... but the higher fuel consumption is something I noticed definitely...

If it just does it when it's warming up I don't see much of an issue.
What do you mean by higher fuel consumption?

 

[eminentguy]

Re: smell and smoke!

Hello..

Now I can confirm the smoke happens only sometimes at startup. Not while operation.
For the fuel consumption, am noticing the amount of fuel am consuming for the same activity - mainly trolling at below 1000 rpm- went up at least 30% more.

Maybe am referring to two not relate issued! But any hints or tips are appreciated.

Firas

If it just does it when it's warming up I don't see much of an issue.
What do you mean by higher fuel consumption?

 

[Fun Times]

Re: smell and smoke!

While there could be a number of items on an fuel injected engine that could be at fault, Here is a list of some steps to take at starting some sort of diagnostic procedures for a running rich situation. They would be to check your spark plugs to see if they appear fouled by too much fuel, check your fuel pressure to see if it's too high and at the same time check to see if the fuel pressure drops dramatically after shutdown, Using an marine diagnostic scan tool, check to see if all the sensor parameters are within specifications, know that all the basic tune up parts are in good clean shape (preferably new), check the condition of the fuel/filter, And check to be sure all the power, ground and electrical connectors are clean and tight and making good contact.

Nowadays it's a good idea to have your fuel injectors inspected and professionally cleaned by a number of places found locally or online should you suspect a faulty fuel injector before buying new. The company should be able to tell you what injectors are non repairable.

Hope this helps, good luck.

 

[DCinVA]

Re: smell and smoke!

Excellent advise above from Fun Times.

 

[278 Vista]

Re: smell and smoke!

Classic symptoms of a coolant temperature sensor that is sending an "out of range" signal to the control module. If this sensor is sending a signal to the control module that the engine is colder than it actually is, the control module will command the injectors to provide a much richer mixture than the engine requires. Thus the smoke at start up and poor fuel economy. As Fun Times said, a scan will nail it down. As a technician when I scan for this, I read the data stream on the scanner and compare it to the temperature reading on my IR thermo gun. Just for the fun of it, grab one at an auto parts store for the same year Chevy 1/2 ton with a 350. It's usually under 20 bux. It's right beside the thermostat housing and easily changed with an 18 or 19mm wrench depending on the year. It takes less than 5 minutes for the average Joe.

 

[eminentguy]

Re: smell and smoke!

Hello again,

The dealer came in and hooked a diagnosing device that showed nothing, which I do t trust! Asked me to use fuel injector cleaner and wait to see the progress!!!

The smoke is still coming even while accelerating and even when engine is at normal temperature! Some time when I throttle on neutral. Get some black carbon powder like floating behind the boat...

Do u still think it's a temp sensor? I just don't trust the face language and recommendations of the mechanics after they saw the symptoms .. So far

Firas

 

[alldodge]

Re: smell and smoke!

Hello again,

The dealer came in and hooked a diagnosing device that showed nothing, which I do t trust! Asked me to use fuel injector cleaner and wait to see the progress!!!

The smoke is still coming even while accelerating and even when engine is at normal temperature! Some time when I throttle on neutral. Get some black carbon powder like floating behind the boat...

Do u still think it's a temp sensor? I just don't trust the face language and recommendations of the mechanics after they saw the symptoms .. So far

Firas

Things that can make an engine run rich:
If the engine doesn't know it's up to temp.
Fuel pressure to high
Throttle position sensor
Restricted flame arrester
You also do a lot of trolling so maybe the IAC

I would start with checking the fuel pressure as Fun Times mentioned

 

[eminentguy]

Re: smell and smoke!

Hi all

Thanks allot for the replies .. I wanted to share the progress so far! So the maintenance guys came over and had no clue what woukd be the reason!
But I just bought fuel injector cleaner, the one used for cars!- and after two treatments, 80% of the smoke is gone !! Not sure if this is a cure or just a pain killer yet!

I find out my Alternator is bad and just got it replaced today.. so hoping maybe! This will help the engine not to go rich again?!

Firas

Hello

My 5.7 OSXI-GF GASOLINE PENTA engine is running just fine .. but I notice at startup sometimes some smoke and smell that I guess is nothing to do with oil burning as engine is 200 hours only and oil does not get less.
I also guess the fuel consumption is high.

I suspect this is to do with injectors, do you think so? What would be possible other reasons?
If injectors, can they be tuned or cleaned? Or replacement is best option available?

This boat was left on water for so long before I bought and fixed it. Maybe this could be a reason? I did 100 hours already using it by now.

Thanks...

Firas

 

[Fun Times]

Re: smell and smoke!

Hi all

Thanks allot for the replies .. I wanted to share the progress so far! So the maintenance guys came over and had no clue what woukd be the reason!
But I just bought fuel injector cleaner, the one used for cars!- and after two treatments, 80% of the smoke is gone !! Not sure if this is a cure or just a pain killer yet!

I find out my Alternator is bad and just got it replaced today.. so hoping maybe! This will help the engine not to go rich again?!

Firas

Having proper voltage is very important to the fuel injection system so yes it may help.

Since you cleaned the fuel injectors, you will want to inspect and most likely change the spark plugs as they may have some gunk on them now.

Let us know how it runs, good luck.

 

[eminentguy]

Re: smell and smoke!

thanks FunTimes

Mentioning the Electricity, I replaced the Alternator after it died suddenly and batteries drained!
I thought it is about Carbon brushes, but then found it is safer to get a new one! so maybe it is to do with that?!



Firas

Having proper voltage is very important to the fuel injection system so yes it may help.

Since you cleaned the fuel injectors, you will want to inspect and most likely change the spark plugs as they may have some gunk on them now.

Let us know how it runs, good luck.