Oil still flows to gas line engine off.

[robalofish]

When my engine is off and sets for 1 or 2 weeks it appears that the oil injection still pushes oil into the gas line as evidenced by a lot of smoke at startup and if I pull the enrichment valve hose from top carburetor I see almost pure oil. The longer it sits the worse the problem. I have changed the check valve prior to the gas line tee any other suggestions?<br /><br />1994 200HP V6 CARB

 

[Kiekhaeferscurse]

Re: Oil still flows to gas line engine off.

Release the Pressure from the external tank ( crack the fill cap)

 

[gss036]

Re: Oil still flows to gas line engine off.

Check you external tank the next time you are running the motor to see if the tank is bulging. Over pressurizing. Loosening the tank cap will take off the pressure that is built up in the tank.

 

[highaltitude]

Re: Oil still flows to gas line engine off.

normal. there are check valves in the oil system.

 

[robalofish]

Re: Oil still flows to gas line engine off.

UPDATE ** UPDATE<br /><br />The reserve tank has been holding pressure for weeks at a time. I didn’t think anything of this as it has done this sense I have had the boat. I found that this is NOT normal. The valve that comes from the engine and supplies the pressure to the remote tank is supposed to bleed off the pressure after 5-10 min. When I checked the valve there was no bleed off occurring. Purchased a new valve and it bleed off as described. So after changing the pressure check valve I have cured the problem. <br /><br />Check Valve number 21-878105 1 <br /><br />Just a note letting you know the outcome.<br /><br />Thanks

 

[srq_fl]

Re: Oil still flows to gas line engine off.

I have a simillar problem with the external oil tank always being pressurize after weeks of unuse. The tank is bulged and the engine smokes heavily when first start.<br /><br />On my 1996 250 EFI, is the Check Valve the "L" shaped piece that screws to the engine block and connects to the rubber hose that pressurises the external oil reservior? <br /><br />Any specs what the pressure should be in external oil thank when the engine is running?<br /><br />Thanks

 

[robalofish]

Re: Oil still flows to gas line engine off.

There are no specs. for the tank that I know of.<br />I just know that after I changed the bad valve I starts like normal and no one calls the fire department anymore.<br /><br />AGAIN -- ITS NOT NORMAL FOR TANK TO HOLD PRESSURE FOR WEEKS AT A TIME.<br /><br />If valve is working correctly it should bleed down the pressure after about 5-10 min. If you crack the cap just after shutting off the engine there should be some pressure. (my guess 5-10 psi).<br /><br />I only wish I had found this about a year ago....

 

[jsr21]

Re: Oil still flows to gas line engine off.

Hey..My 94 Merc 225 does the same thing. Super hard to start after sitting overnight and smokes HEAVILY on start up. I checked and my lines and carbs were almost pure oil. Anyways, does anyone know if the part number listed above for the check valve would apply to my engine as well? I can't find anything for it on Mercury Express Parts...Thx all

 

[rodbolt]

Re: Oil still flows to gas line engine off.

JSR21<br /> replace both the block pressure valve and the oil line check valve at the same time. one is just beside the oil pump on the fuel intake line and the other is just below the starter on the fwd stbd side.<br /> do them both at the same time.

 

[robalofish]

Re: Oil still flows to gas line engine off.

Does the tank hold pressure for hours after you run it (should bleed off in about 10 min)?<br /><br />If so you can pull the valve from the lower side of block and check it.<br /><br />If you put in your ser# mercparts should be able to find the part#.

 

[jsr21]

Re: Oil still flows to gas line engine off.

rodbolt..which is which? The block pressure valve is the one that screws into the right side of block near the bottom, or is that what they call the oil line check valve? Thx..sorry for all the questions.

 

[rodbolt]

Re: Oil still flows to gas line engine off.

hello<br /> the one with threads the service manual calls a pulse fitting. goes in the block. the other is called a 2 psi check valve and goes in the fuel pump suction line. its just been my experience over 20 years or so of V6 merc work that if one is bad so is the other. I always replace them in pairs. saves time opening it up twice. this is a very very common problem. right up with oil modules, cracked engine caps and failed switchboxes/stators.

 

[jsr21]

Re: Oil still flows to gas line engine off.

Thx for your reply Rodbolt...so from the oil pump, there is a clear tube running up towards a y fitting.Is this the fuel pump suction line? Right before this y fitting, it looks like there is a check valve.Would this be the 2 psi check valve you are talking about? The y fitting looks like it connects the oil line and fuel line together and blends the two before getting to the fuel pump. Is this right?