changing injector

[Terry Forshier]

A few days ago I decided to check on the tightness of the top injector on the xp 25 diesel in the 1988 C34 sailboat. I could see little bubbles around the insertion hole when I had soapy water on the motor and also was getting some evidence that it was leaking out there as the paint around the hole was wearing off. I ordered a new injector last week and new seals. (copper washers) and then took off the old one. It was leaking compression and I thought the seal that seats it down was bad. Well, there was no copper washer to seat it in there at all and around the plug threads was a lot of carbon build up. I cleaned it all up and put in a new one bled the system and started it. It was slow starting but finally started. However, it had no power. I put it in gear at the dock and it would die.  After fiddeleing with the fuel hoses i got it running but it still would only run at about 2/3 rpm in gear.
I am thinking that the new injector is not put in right or just not firing. At first thinking fuel.
I ran a new fuel line from the pump to the filter on the motor, changed the filter and still same deal.Then I took the old injector and put it back in using a new seat washer. Still no power. At idol engine runs at 3500 rpm. Under load, 1600.  I searched teck notes but did not find what I thought was an answer.  How can I tell if one cylinder is not firing and which one? Is there a tester? Any other Ideas would be appreciated. ?

[Ken Juul]

It sounds to me like it is a fuel problem.  I think I would re-bleed the system.  Use the soap water trick to check for compression leaks as you did previously.  Re look at all your work with a critical eye, make sure everything is hooked up correctly.  Everyone makes mistakes every once in a while.  If you have question on where parts go, the parts diagram on the manual page of the wiki has a very good parts breakdown.

[Ron Hill]

Terry : I'm glad that you used my "soapywater" in the injector hole to find that it was leaking.
If your engine were only firing on 1 or 2 cylinders, you'd think it was getting ready to jump out of the engine mounts - that kind of vibration!!

As I wrote in the Mainsheet "Cleanliness is next to Godliness" - when changing injectors.  That's why I recommend having a shop vac to suck up all of the paint chips and do it frequently.  The problem that you describe sounds like a lack of fuel, but it's probably may NOT be from bleeding.  It could be from the paint chips have gotten into one or more injectors while the fuel lines were disconnected.  

If you want to check for completely bled line here's what I'd do:  Shut off the raw water thru hull.  Crack the fuel line nut on the top of the injector and turn the engine over with the fuel cut off pulled.  If you get fuel coming out of the top of the injector the line is bled.

You might have to take your injectors to a diesel place and have them checked.  Most do not charge to check the pressure pop and spray pattern.

Look again because I can't believe that there was no crush copper washer on that injector!!  The factory would have not forgotten it, but a PO might have?!  Any injector without that washer should be noticeably lower that the other two injectors!!!
A few thoughts

[ozzie]

Here is some info on how to bleed the fuel system.
I think your original problem was a slightly loose injector and carbon had built up under the seat.
It is possible and I have seen it before that the original copper washer is still under the injector. I would recommend that you take out the injector and with a screwdriver scape in the bottom of the injector hole and see if it looks like cooper the old washer is stuck in there.
A fuel injection shop can quickly test your injectors to eliminate them as a possible problem.  
Before reassembly give the engine a quick spin over ( if you only have one injector out make sure all other injectors are bolted down ) to clean out the holes and clean fuel will squirt out of the injector lines and clean out any dirt or paint.
Keep everything as clean as possible.

Also have a look at the exhaust when it is running.

Possible problems.
Black smoke - restricted air flow, dirty or worn injectors, over fueling
White smoke - low compression,  a dripping injector , coolant ( head gasket )
Blue/Black smoke - oil burning (valve guides or engine problems) , timing
No smoke - no fuel

Good luck,
ozzie

Universal M-25


   BLEEDING THE FUEL SYSTEM:

It will be necessary to bleed the fuel system to achieve a steady air free flow of fuel if any of the following have occured: Models M-12, M2-12, M3-20, and M4-30 have self bleeding fuel systems.

1. Running out of fuel.

2. If fuel shut off valve is left closed and engine runs out of fuel.

3. Replacing fuel filter.

4. Fuel injector nozzle or injector pump repair.

5. After repairing or replacing any fuel line.

6. Before putting engine back into service in the spring, if fuel system has been drained.

7. Replacement of electric or mechanical fuel pump.

8. Any time air is permitted to enter the fuel system.

BLEEDING PROCEDURE:

Be sure to have some means available to catch or absorb any fuel escaping during the bleeding process so that it will not accumulate in the engine compartment or bilge.
1. Be sure there is a sufficient supply of fuel in the fuel tank.

2. Open the fuel shut-off valve at the tank.

3. Start the electric fuel pump by turning the ignition key to the "ON" position on models 18,
20, 25, 30, 50, all models after 1986.

4. Model 15 has a mechanical fuel pump. Therefore with decompression on, turn engine over with starter. Crank at 10 second intervals while doing steps #5 and 7.

5. Slowly loosen the air bleed plug on the fuel filter, letting air escape until an air free flow of fuel is evident. (1986 models see item 7).

6. At this time, tighten the air bleed plug on the filter.

7. Slowly loosen the air bleed plug on the injector pump, letting air escape until an air free flow of fuel is evident. Units with a self bleed return valve, open for a short period then start engine, as soon as engine runs smooth close valve. Model-12 has continuous fuel bleeding.

8. At this time, tighten the air bleed plug or knurled knob on the injector pump.

9. The fuel system should now be properly bled and ready for operation.

Refer to starting instructions before attempting to start the engine after bleeding the fuel system.

CAUTION: Excessive cranking with sea cock valve open can cause water accumulation in the muffler and possibly back up into the engine. Drain muffler as needed.

[Stu Jackson]

Ozzie, thanks for the post.  For others maybe new to this message board, Ozzie's post is direct from the engine manual.  Over the years, we've "improved" on that procedure somewhat.  Thanks to Ken for this one: http://c34.org/bbs/index.php/topic,2884.0.html  Use the fuel pump, don't bother messing with the Racor filter hand pump, all it'll do is knurl your fingers unnecessarily.

[Terry Forshier]

After checking and rechecking I still could not find a problem in the fuel line. I took off the engine mounted fuel filter again and checked the clamps. Blew through the line into the filter. Nothing unusual. bled lines again, reinstalled. Started motor still just "punky" hardly reved to top end. Leaned over motor and jiggled the fuel line. Motor stopped. Started gain, put rag over filter and shook it. Motor stopped. Kept looking. Unloosened the screw on the wire that sets the motor stop on the pannel in cockpit. Noticed I had a lot of wire at the end. With screw lose went to cockpit and raised and lowered the cable handle. Went to full length at down position. Tightened stop on wire giving more play to the shut off cable. Restarted motor. Ran like a champ. Noticed that there was no stop on the cable as it ran along the side of the engine and through a little guide hole. The fuel shut off was never in the all the way open position. When jiggeling the line I was also moving the shut off cable and closing off fuel.That must be why the motor was hard to start unless the lever was on full position on the helm, why the motor would lose rpm after awhile. The fuel line was not all the way open. It has been that way since I purchased the boat 3 1/2 years ago. It has a lot more power now. A lot more. Sometimes the simplest things. ???Terry

[Jack Hutteball]

Terry, the same thing happened to me when we had our 27.   The cable was loose on the shut off lever so it would not fully open.  Took me a while to figure that one out.  I had to have someone stop and start the engine while i watched, then it was simple.  I should have given you a heads up on that when I red your earlier posts.
Jack

[Stu Jackson]

Terry, really glad to hear you sourced the problem and figured it out!

Reminds me of this, like Jack, just not too swift on the uptake, thinking fuel, not shutoff:  http://c34.org/bbs/index.php/topic,4565.0.html

[Ron Hill]

Terry : I'm glad to see your post.  I would have never thought to tell someone to check the open/close throw of the fuel cut off and throttle - even though I've removed and reinstalled the engine twice!! Guess it's one of those things I instinctively do!
 
Mentioned earlier in this post, electric fuel pump or manual fuel pump -- it's NOT a good idea to introduce air into the fuel system by NOT filling the changed filter with fuel first.  You are just asking for trouble.
A few thoughts