Hi:
Just changed the two filters on Allure and can not seem to get the air out of the fuel system. I pre filled the two filters before installing to minimize the amount of bleeding and it didn't seem to help one bit. The primary filter #63390 has a bleed screw on top of the casting it screws on to and I've bled that using the lift pump running (still getting foam). I've bled the injector pump with the lift pump running (still getting foam). I've also cracked open the feed lines (one at a time) at the injector itself and tried to push out the air by spinning the engine over with the starter (very little fuel came out). I realize everthing after the injector pump is high pressure that is why I spun the motor over with the metal injector lines lose at the injector. I realize the following about the fuel system.
1: The lift pump pulls the fuel threw the secondary filter (which is a combination water separator / fuel filter). It's a small racor with a plastic bowl on the bottom (which was pre filled) and has no bleed screw on it. It does have a spring loaded drain on the bottom but that is for draining any water out in the fuel bowl.
2: The lift pump "out" then pumps the fuel into and through the primary filter and on to the injector pump.
3. Anything after the injector pump is HIGH PRESSURE and on to the injectors them self.
4. If the fuel delivery system is working properly the fuel should really come squirting out of the feed line to the injector if it's loosend up and the motor spun over.
AM I NOT BLEEDING THE SYSTEM LONG ENOUGH, how long does it take to bleed out the air? I've pushed fuel (mostly foam) out the two bleeders for about a minute or two and the foam will not turn into clear fuel.
WHAT AM I NOT SEEING OR DOING WRONG HERE.
Thanks
Bruce
S/V Allure
Hi All:
M-12 engine running again. Replaced some fuel lines, went back to a 10 micron filter and replaced the copper washers under the bleed screw and banjo fitting on the injector. Bled the system using the lift pump. Used a glass jar and a longer piece of fuel line to bleed with so I could see when the bubbles stopped. Did the fuel separator first, the the bleed screw on top of the casting for the secondary filter and then the bleeder on the injector pump. Hit the glow plugs for 20 seconds and it fired off in about 3 or 4 seconds. Started it again three more times over two days to make sure it did not loose it's prime and it seems good to go. Has anyone else had a problem with the 2 micron filters, Perhaps it makes the lift pump work to hard pulling the fuel through it? Really don't know what fixed the bleeding of the air in the system problem but it now works fine.
Bruce
S/V allure
Ahoy Bruce;
I posted some suggestions for you but the site must have ignored them when it was down. Glad to hear you got her running again. I run a Yanmar 1gm10 in my little ship and had somewhat similar problems recently. Finally, after bleeding it over and over again, it's running fine. ??? I even tried bleeding it "backwards." Didn't seem to help. Not a lot of diesel advice found here, mostly outboard ships. I recommend the marinedieseldirect website if you haven't seen that one yet. http://www.marinedieseldirect.com/ There's a lot of forums on it.
Fair Winds
BobL
Bruce, Glad to hear you were able to solve your problem. I had a similar problem with Universal M-2 last season. Turned out to be an air leak at the exit side fitting/hose connection on my raycore filter assembly. It was not obvious because there were not any visible leaks anywhere but apparently when engine turns over it "pulls" fuel thru the filter and a less than perfect connection allowed for air to be sucked in. What we ended up doing was bypassing the primary filter (the raycore unit) and connecting the fuel line from electric pump directly to the secondary filter on the engine block. The engine started up immediately & repeatably with no further issues. According to the manual the system is "self priming". On my 27, turning the key on the engine panel energizes the electric pump which will force fuel thru the system & back to the tank. On some larger Universal motors, they say to crack the connection at the injector but for the M-2 it should not be necessary.
One interesting thing... the marina mechanic used a can of 100% silicone spray when troubleshooting in the same way you would use "insta start" or either spray on your gas lawn mower. He warned however "make sure to use only 100% silicone" on a diesel.
Bille
Hi Bille:
I put about seven hours on the engine this weekend and it ran perfect. I thought that with the 2 micron filter on the racor that the lift pump might has been sucking so hard to get the fuel through it might have been picking up air from somewhere along the fuel line (just a theory). I would like to put a vacuum gage on in between the lift pump and the racor so that I would know when the filter needs to be changed. I have seen this on bigger boats. When the vacuum gage starts to read higher it means that the lift pump is working harder to pull the fuel through the racor, thus it was getting used up and time to change it. Some day....but not today.
Thanks for your reply......
Bruce
S/V Allure
Hi:
I did find one other "issue", that perhaps added to my problem. The fitting coming out of the lift pump was 1/4" and had a 1/4" fuel line connected to it. The inlet fitting on the filter housing at the back of the motor (before the fuel goes to the injector pump) was 5/16". The 1/4" line had been forced onto the 5/16" fitting and perhaps had been compromised. I found this out when I cut a small section of line off to the end to get a fresh section for the fitting and it would not easily slide back on the fitting. Ended up changing the fitting on the outlet side of the lift pump to take a 5/16' line like the inlet on the filter housing and replaced that fuel line with 5/16" size.
Thanks again...still running perfect.
Bruce
S/V Allure