1995 Merc 225 efi What is causing this?

[Seanj85]

Getting sludge out my exhaust, along with a cough at idle. Anybody have any knowledge on why this may be happening?

[roadkill636]

Its oil mixed with water. Hopefully your fuel pil and not gearcase oil
Mite be running a bit rich..

[Seanj85]

Its oil mixed with water. Hopefully your fuel pil and not gearcase oil
Mite be running a bit rich..

Gear oil looks clean. Could it be the oil pump?

[tlwjkw]

un-burnt fuel mixin' with water.. could be idle timin'? dead or non firin' cylinder/cylinders... maybe?

[Seanj85]

Any ideas on what to troubleshoot first?

[Merc 2.5]

Does it have pulse fuel pump? They have a tendency to flood the cyl providing the pulse if diaphragm is bad , will pretty much pour raw fuel out of prop

[Seanj85]

Does it have pulse fuel pump? They have a tendency to flood the cyl providing the pulse if diaphragm is bad , will pretty much pour raw fuel out of prop

I am not sure, attached is the style fuel pump. The motor seems to run okay and have power, just has a cough... and of course the sludge. I am getting spark on all 6. Sorry for the lousy pictures, I screen captured them from my phone.

[Merc 2.5]

That's a diaphragm pump , if pump was bad prob run like crap or run out gas at wot ,but I had one wouldnt idle for nothin and raw fuel runnin out prop ,but run fine close to wot cause it could burn most of it off worth a look or rebuild pump is cheap , could be tps also, temp sensor, etc

[XstreamVking]

Seems I remember a return hose with a screen filter in it that could cause a over fueling condition. Those old efi's are so tough you could pour fuel down the intake and they would still run.

[Seanj85]

I will order parts and rebuild it. I will report back. Seems like a logical place to start.

[Seanj85]

Seems I remember a return hose with a screen filter in it that could cause a over fueling condition. Those old efi's are so tough you could pour fuel down the intake and they would still run.

Inside the fuel pump or vst?

[Merc 2.5]

Plz inspect b4 throwing $ at it , xstream pretty gud with 3.0 and other gud to ,

[Seanj85]

Plz inspect b4 throwing $ at it , xstream pretty gud with 3.0 and other gud to ,

Alrighty I will crack her open and check it out. If it looks good can i close it back up without new gaskets?

[Merc 2.5]

Depends how long been on there, if I'm not mistaken, u can split it and look at diaphragm without messin up gaskets ? I think haha

[XstreamVking]

Look at a schematic on boats .net or some other and locate all the parts b4 opening. Might need another vst o-ring...They are spendy...