How do I find air leak in fuel supply? (Solenoid & Glow Plugs, too)

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Sundance

I'm having some engine problems, I think I know what is wrong, but looking for some advise how to fix.  I am getting air in the fuel supply to the engine, when I bleed the system from the injectors, I get the engine started.  I run for a awhile, shut down, let sit for about an hour and it starts fine, perfect, no hesitation.  I let it sit overnight and I have the same problem as I first had.  I have tightened all the hose clamps, visually inspected the fuel supply lines, and at this point I'm looking for advise on how to find a leak (obviously extremely small) in the fuel lines.  Based on the symptoms, is there a specific place I should look for the leak?  Because I need to bleed it from the injectors, I feel the problem is after the primary fuel filter.  Does it sound like the problem is in the fuel return line?  I have searched the database, but I have not found any tricks or tips, just the diagnosis.  Any help tracking down my leak would be much appreciated.  Thanks.

After reading some posts, do you think my symptoms sound like a glow plug problem?  I hear the "click" when I hit the glow plugs, I get the 2v drop, but if my plugs were not working properly, would I get the engine started by bleeding it?  It seems that if I had some place where I get air in the system, the engine would run rough or die while running, that's not the case.  Hmmmm?
Jeff
2001 C34 #1581
"Sundance"
Sandusky, OH

Stu Jackson

#1
Not sure what you mean by: "when I bleed the system from the injectors..." Is this the knurled knob?

One of our members reported a damaged Racor fuel filter element that let air in.

I reported that I'd left the darned vent nut loose on the top of the filter.

There is no one particular place to look for a leak - you've made a good start, but if visually checking, you'll need to check those places that you can't see, using a mirror and flashlight.  Have you removed the big wooden panel in the aft cabin and checked the fuel connections at the tank?  Is the fuel valve open? (Don't ask, I've left it closed and wondered why the engine wouldn't start after I replaced a filter...duh!)

Are you sure that both of the filters are on properly?  Since you have checked the hoses and the clamps, the only other thing to do is to use soapy water to check.  The fuel return line is under pressure and won't add air to the system it is only the supply lines that do that.

If you have air getting into the system, the engine will not run rough, it will die. Period.

What engine do you have?  From your hull # I'd guess an M25XP.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

RV61

Sundance,
If air in the fuel is the issue check both your primary and Racor filters to be sure gaskets properly seated. In reading your post the way I perceive  what is happening is the engine cranks and does not fire until you crack the injectors and at that time you are getting fuel then fires and runs fine fine? Then starts easily
an hour later engine as it is still warm. I think you are right on  the Glow Plug
not getting enough Power. Try pushing glow plug for 45 seconds then cranks 5 to 10 if nothing push glow again for 45 crank again if nothing go one more. If she starts then I think you will want to check your plugs, wiring and connections to the plugs. I am wondering if she is starting after you bleed the system is because you have more than likely been on the glow plug for third time and and not the bleeding. I would think if you had a fuel issue be it air or dirt she would not run fine after she started.
 
Rick V
Interlude
1986 Hull #237
Lake Erie

Sundance

By bleeding from the injector I mean cracking the nut suecuring the fuel line to the injector till diesel flows out then tightening down.

I'm starting to think I have glow plug problem as once I get it going I have no problems at all. It sounds like if I had any kind of air leak I would have engine problems while running. last time I started the engine, I ran it for about 2 hours.

Does the "click" when I hit the glow plugs mean anything?  I can't remember if this always happens or not, I never payed attention.
Jeff
2001 C34 #1581
"Sundance"
Sandusky, OH

Ken Heyman

Jeff,
can you hear a steady "click click" from your electric fuel pump. If so your system is  pressurized and you need to look elsewhere for the answer. If not then proceed as mentioned above---filters connections etc.

Good luck,

Ken
Ken Heyman
1988 c34 #535
"Wholesailor"
Chicago, Il

Sundance

Jeff
2001 C34 #1581
"Sundance"
Sandusky, OH

Stu Jackson

#6
Jeff, U wrote:  "By bleeding from the injector I mean cracking the nut securing the fuel line to the injector till diesel flows out then tightening down."

You (almost) don't EVER need to do that.  I would think that you've read Ken Heyman's many times referenced fuel bleeding procedures, I know I have.  See: http://c34.org/bbs/index.php?topic=2884.0

All you need to do is:

1.  use the knurled knob when you replace the Racor under the head sink

2.  use the nut on the top of the engine mounted secondary filter when you change that filter

I have never had need to open an injector connection, nor do I recall reading of a need to do that to successfully bleed our M25-series engines.

If you haven't done the glow plug solenoid upgrade, consider doing it now that you are suspecting your glow plugs.  That'll force you to check each and every connection, including the one to the starter solenoid, which could be something as simple as just plain loose.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

sail4dale

I had that same problem on my Cat30 with the M25 engine.  It had an electric fuel pump with a screen and cap on the bottom.

There was a brazed hex on the cap that facilitated its removal.  The braze had corroded thru and resulted in an air leak in the pump.  Replace the cap and more air.
Cat34 Mk II True Luff #1582  2001
San Pedro, CA (Port of Los Angeles)

Ron Hill

Jeff : I didn't see any mention of the age of your fuel lines.  I've posted a number of time that I use a leather "cushion" under the small hose clamps, as they tend to cut into the lines.
I wouldn't think that you have a glow plug problem if you leave them on for 30 sec. (engine cold) & it starts. 
What you may want to try is to leave the bleed valve "cracked" about a 1/4 turn ON rather than shutting it OFF.  That way you'll have a self bleeding fuel system. 
A thought. :wink:
Ron, Apache #788

Stu Jackson

The fuel pump belongs AFTER the Racor filter.  If not plumbed that way (usually NOT by the factory) it should be re-piped.  Fuel tank -- filter --- electric fuel pump.  Not like this hasn't been mentioned some many times before.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

Sundance

Fuel pump is placed after filter.

Fuel lines are original, the "cushion" is a good idea.  Replacing my fuel lines is on the list, I will consider the cushion when I replace.

I think the PO may have done the glow plug upgrade as I hear the semi loud click when I hit the glow plugs and I'm pretty sure they are wired to a solenoid.  I just thought this was normal, but after reading up it appears the upgrade may have been done.

Ron: Thanks for the suggestion, I will try the 1/4 trun bleeding proceedure.  Considering I'm pretty sure the glow plug project has been completed, I usually leave them on for 20 sec. and get an immediate start.  The problem currently is that I use the same 20 sec. and the engine just cranks.  I need to check the plugs to make sure this isn't my problem, but I'm starting to suspect this may be the issue.

Thanks.
Jeff
2001 C34 #1581
"Sundance"
Sandusky, OH

Mike and Joanne Stimmler

Ron, How much leather do you use on your hose clamps and what thickness is it? Just enough to go around one wrap or multiple wraps?

Jeff, I think you should try starting your engine multiple times using longer gloplug times WITHOUT bleeding the fuel to prove whether it's a gloplug or a fuel issue. If the engine Does start after multiple tries without bleeding the fuel, then it's a gloplug issue. If the engine does NOT start until you bleed the fuel system, then there is air getting into the system as you suspected.

There is an old thread discribing the troubles I had with my gloplugs and I believe that the plugs gradually went bad one at a time, making it harder to start but still possible after a longer pre heat time until it got to a point where it would not start at all.
After replacing all three of the plugs, it now starts first time, every time.

Hope this helps
Mike
Mike and Joanne Stimmler
Former owner of Calerpitter
'89 Tall Rig Fin keel #940
San Diego/Mission Bay
mjstimmler@cox.net

Ron Hill

#12
Mike : I use only one wrap and it's slightly wider than the clamp.  Just make sure that it is cut in length so the ends abut when the clamp is tight.  I've used it as a cushion between the clamps and fuel lines and on the hump hose.
The leather I got at a boat show from the guys that make the leather wheel covers.  They have the packages of scraps for $10 or so.  Nice leather for the price. 
A thought  :wink:
Ron, Apache #788

Sundance

I thought I would take a second and let you know the conclusion to my problem.  I eventual was conviced it was not a fuel problem due to the fact the engine ran fine once I got it going.  I immediately thought it was the glow plugs.  I have the glow plug upgrade installed.  I heard the click of the solenoid when I hit the glow plugs, but only saw about a 1v drop in voltage meter, plus upon futher investigation, the 30amp fuse between the starter and solenoid was blown.  Replaced the fuse, but suspected this wasn't the problem, I was right. I then thought I might have a short in one of the plugs, but knew this is pretty rare.  I cleaned all my connections and still nothing.  Eventually I narrowed it down to the solenoid itself.  Replaced solenoid and works perfect.  I even had a chance to start the engine the next day on a chilly 40 degree morning in Cleveland, 20 sec of glow plug time and started right up.  I guess what I learned and would pass on is just because the solenoid clicks as usual it doesn't necessarily mean it is working.  Thanks for the help.
Jeff
2001 C34 #1581
"Sundance"
Sandusky, OH

Mike and Joanne Stimmler

Jeff, great to hear that you got it figured out. BTW, I did have a short in one of my glow plugs and another had an open.

Mike
Mike and Joanne Stimmler
Former owner of Calerpitter
'89 Tall Rig Fin keel #940
San Diego/Mission Bay
mjstimmler@cox.net