So I have been told that my fuel injectors need cleaning on my 1983 M25 engine. Would you suggest trying a fuel additive or is that just a waste of time?
Most diesel mechanics (and I think service manuals, too) will tell you that the injectors should be serviced (read rebuilt or replaced) every 1000 hours or so. Even though they are only turning liquid diesel into a fine mist, they do wear. Look for a diesel shop near you that services diesel trucks. The cost will be 1/3-1/2 of what you would pay at a Westerbeke/Universal facility.
[QUOTE=TomSoko;11947]Most diesel mechanics (and I think service manuals, too) will tell you that the injectors should be serviced (read rebuilt or replaced) every 1000 hours or so. Even though they are only turning liquid diesel into a fine mist, they do wear. Look for a diesel shop near you that services diesel trucks. The cost will be 1/3-1/2 of what you would pay at a Westerbeke/Universal facility.[/QUOTE]
For the engine to run smoothly and efficiently, the injectors are required to spray a fine mist of fuel into the cylinders. If the injector has excessive carbon around the tip, dirt in the nozzle or for some other reason the fuel does not get properly sprayed, the fuel will not get completely burned. This will result in reduced power and efficiency. It can also cause black smoke.
Often one injector is worse than the others, and this can cause missing and a rough running engine.
The injector tip acts like a valve and completely blocks the fuel flow when the injector pump is not sending the high pressure injection pulse to the injector. If this valve leaks, fuel will drip into the cylinder when it is not supposed to and cause the engine to knock.
Diesel shops have a high pressure hand pump that the injectors are connected to that allows the mechanic to observe the spray pattern, as well as test what pressure it takes to open the valve. Some shops suggest that even new injectors be tested.
—
Gary Teeter
1989 C36 "AnnieG"
Std Rig #966, M25xp
Everett, WA
I have read on other forums that if you purchase some diesel injector cleaner used to be put in the gas tank but instead put it directly into the fuel filter it will clean the injectors. Any thoughts on this??
When I replace our primary fuel filter, I fill it with injector cleaner instead of diesel fuel. Most of it goes back to the tank on the return line anyway when I bleed the engine (M25). Would work with self-bleeding M35s, too. I find it easier to pour from a plastic container than to try to get diesel. I've also done it without filling the new primary filter with anything, and that works, too, since the lift pump gets all the air out.
If you have the newer electrical arrangement on he M35s, where the lift pump only goes on when the glow plugs are on, and then comes back on when the oil pressure switch makes, the engine self-bleeding is necessary. It gets tricky when you have to bleed the secondary filter from the nut on the top of it.
Lori Lee,
I'm sure that injector cleaner will help somewhat, but if your injectors have enough hours on them, no amount of cleaner will work. They need to be rebuilt or replaced. IMHO.
Its not a hard job, just make sure when you take them out not to get any dirt or junk in the cylinders. When I did it, I used a compressor to blow everything loose around the injectiors out before I removed them, then I stuffed clean cotton, non-shredding rags into the holes until I got the injectors back. It seems to me (it was a while ago) that it only cost about $60 to have them cleaned and repaired as needed.
I actually found it took more effort to get the fuel lines lined up correctly when reinstalling than any other part of the job... you don't want to cross thread any going back in.
—
Chuck Parker HelenRita 2072 Mk II
2002 Tall Rig - Winged Keel
Atlantic Highlands, NJ
Most diesel mechanics (and I think service manuals, too) will tell you that the injectors should be serviced (read rebuilt or replaced) every 1000 hours or so. Even though they are only turning liquid diesel into a fine mist, they do wear. Look for a diesel shop near you that services diesel trucks. The cost will be 1/3-1/2 of what you would pay at a Westerbeke/Universal facility.
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT
[QUOTE=TomSoko;11947]Most diesel mechanics (and I think service manuals, too) will tell you that the injectors should be serviced (read rebuilt or replaced) every 1000 hours or so. Even though they are only turning liquid diesel into a fine mist, they do wear. Look for a diesel shop near you that services diesel trucks. The cost will be 1/3-1/2 of what you would pay at a Westerbeke/Universal facility.[/QUOTE]
What are the signs that injectors need replacing?
Ed S.
Osprey
1988 mk I, # 845
Ventura, Ca.
For the engine to run smoothly and efficiently, the injectors are required to spray a fine mist of fuel into the cylinders. If the injector has excessive carbon around the tip, dirt in the nozzle or for some other reason the fuel does not get properly sprayed, the fuel will not get completely burned. This will result in reduced power and efficiency. It can also cause black smoke.
Often one injector is worse than the others, and this can cause missing and a rough running engine.
The injector tip acts like a valve and completely blocks the fuel flow when the injector pump is not sending the high pressure injection pulse to the injector. If this valve leaks, fuel will drip into the cylinder when it is not supposed to and cause the engine to knock.
Diesel shops have a high pressure hand pump that the injectors are connected to that allows the mechanic to observe the spray pattern, as well as test what pressure it takes to open the valve. Some shops suggest that even new injectors be tested.
Gary Teeter
1989 C36 "AnnieG"
Std Rig #966, M25xp
Everett, WA
I have read on other forums that if you purchase some diesel injector cleaner used to be put in the gas tank but instead put it directly into the fuel filter it will clean the injectors. Any thoughts on this??
"Lori Lee"
San Diego, CA
1983 C36
Hull # 0083
When I replace our primary fuel filter, I fill it with injector cleaner instead of diesel fuel. Most of it goes back to the tank on the return line anyway when I bleed the engine (M25). Would work with self-bleeding M35s, too. I find it easier to pour from a plastic container than to try to get diesel. I've also done it without filling the new primary filter with anything, and that works, too, since the lift pump gets all the air out.
If you have the newer electrical arrangement on he M35s, where the lift pump only goes on when the glow plugs are on, and then comes back on when the oil pressure switch makes, the engine self-bleeding is necessary. It gets tricky when you have to bleed the secondary filter from the nut on the top of it.
See: [url]http://c34.org/bbs/index.php/topic,5078.30.html[/url]
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)
Lori Lee,
I'm sure that injector cleaner will help somewhat, but if your injectors have enough hours on them, no amount of cleaner will work. They need to be rebuilt or replaced. IMHO.
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT
Its not a hard job, just make sure when you take them out not to get any dirt or junk in the cylinders. When I did it, I used a compressor to blow everything loose around the injectiors out before I removed them, then I stuffed clean cotton, non-shredding rags into the holes until I got the injectors back. It seems to me (it was a while ago) that it only cost about $60 to have them cleaned and repaired as needed.
I actually found it took more effort to get the fuel lines lined up correctly when reinstalling than any other part of the job... you don't want to cross thread any going back in.
Chuck Parker
HelenRita 2072 Mk II
2002 Tall Rig - Winged Keel
Atlantic Highlands, NJ