Injector inspection??

[Wmiii]

I am getting ready to head out to the Bahamas in a few weeks. I recently noticed that I have supposed to check my fuel injectors every 600-1000 hrs. With over 1500 hrs on my Yanmar, I guess I should get this done or do it. What is involved in this inspection and do I really need to do it? The engine seems to run just fine.

Wm Mayberry
OPTIMYSTIQUE
IP 37-30

[CSY Man]

Do it.....

Ya can pull the injectors and have them tested for free.
If the spray pattern is bad, have them re-built.
I paid $60 a piece for Perkins injectors last year.

The engine ran fine or so I thought, but I had exceeded the recommended time by 150 hours.

I got to watch the spray pattern when they tested the injectors, and it was lousy..Fuel just trickling and dribling out instead of being atomized.

Makes a difference in temps, smoke and performance/fuel consumption.

[hellosailor]

CSY-
Who tests for free? And what do they charge for rebuilds?

[Sunspot Baby]

Almost any truck diesel service center can test and rebuild injectors.

If engines are Volvo, it takes a special tool to remove and install.

George

[CSY Man]

CSY-
Who tests for free? And what do they charge for rebuilds?

I use RPM Diesel in Ft. Lauderdale, but I belive most places test 'em for free.

$60.00 for rebuild, each.

[Wmiii]

I'm away from the boat right now, so can't just look and see.

Also anything special about replacing them? Do they need to be torked(SP) to specific ftlbs?

Thanks,
Wm Mayberry
OPTIMYSTIQUE
IP 37-30

[CSY Man]

I can only speak for my Perkins 4-108, but yes they need to be torqued to a certain value.

Also new copper washers, etc but those should be included in the rebuild price.
(I guess some companies are using aluminum washers these days?)

[never monday]

Wm,
The injectors in your Yanmar are fairly easy to pull. Turn off your fuel supply at the tank. Remove the return lines. They are the small rubber hoses between the injectors. Losen the injector pipe nut on top of the injector with a 17mm wrench. The steel lines have enough flex in them to let the injector lift out without removing the steel pipes. There are 10mm nuts next to each injector on the saddle clamp. Remove these nuts. The injectors my be dificult to just pull out. Try rotating them and/or spraying PB Blaster between the head and injector. At the bottom of the injector hole is a copper sealing washer. It's a good idea to replace these, but not mandatory each time. There are no other copper washers you will need to service for this job. Torque spec for the saddle clamp bolt is 14.5 to 21.7 ft/lbs

[Wmiii]

When I get back down to Florida I'll see what I can do. I'll need to find a tork wrench though.

Wm

[never monday]

15 ft/lbs = basicly tight, not super tight.

[Wmiii]

So I guess my question now is... If all seems to be fine, Do I need to get them inspected?

Wm Mayberry
Currently in Titusville, FL

[Alan Wheeler]

YES!! Most likely the spray pattern is becoming poor. Inspection is simple. the injector is coupled to a hand operated device with a pressure gauge. The handle is pumped and the pressure read at what point the injector opens. The spray pattern is observed. If the spray patten is poor, the injector may need a simple clean. If that doesn't help, then it may need re-seating or at worse, a new tip fitted. If the opening pressure is not correct and the fule dribbles out, it is often a simple case of the tension on the internal spring requireing adjustment.
At the hrs you have done, I imagine a simple clean is all that will be required and maybe an adjustment.
The process is very simple and if you know what you are looking for, anyone can actually do it. The trick is having the device to test the injector on. So taking it to a shop is the best way to do it.

[hellosailor]

Wm, I'd say you have three choices:

1- If it runs fine, leave it alone. Cheap and simple.

2- If you want to go offshore, "Trust but verify". Never take anything on faith, pull the injectors and have them inspected. Odds are that you can improve their performance by having them rebuilt/cleaned and calibrated, in any case. Disadvantage? Yeah, some time and money. But you will KNOW for sure that you've got 100% performance and power from them. You do it, do it once, don't worry about it for another five years.<G>

Depending on your budget...you can either send yours out for a rebuild (might take a week or two), or send yours out and in the meantime replace them with new ones. Gonna double your cost, sure. But also means you have a set of spare injectors on hand, in the unlikely (very unlikely) event that one clogs/jams in the future. Personally, I'd say just sending yours out and waiting for them to come back in enough.

Remember that you will need new o-rings to reinstall the injectors, and possibly crush washers. And if the thought intimidates you, this should be a simple 1-hour job for a mechanic who can show you what to do, and go over how to purge the fuel lines with you at the same time. (Purging fuel lines also usually requires new crush washers, avoid the temptation to just re-use the old ones, crush washers are cheap by the dozen.)

[Razman23]

Originally Posted by never monday

Wm,
The injectors in your Yanmar are fairly easy to pull. Turn off your fuel supply at the tank. Remove the return lines. They are the small rubber hoses between the injectors. Losen the injector pipe nut on top of the injector with a 17mm wrench. The steel lines have enough flex in them to let the injector lift out without removing the steel pipes. There are 10mm nuts next to each injector on the saddle clamp. Remove these nuts. The injectors my be dificult to just pull out. Try rotating them and/or spraying PB Blaster between the head and injector. At the bottom of the injector hole is a copper sealing washer. It's a good idea to replace these, but not mandatory each time. There are no other copper washers you will need to service for this job. Torque spec for the saddle clamp bolt is 14.5 to 21.7 ft/lbs

I take it that the system doesnt need to be bleed since it is on the downstream side of the pump?

Would you suggest plugging the injector hole in the head with a rag or something to keep any nastys out?

[never monday]

Definetly put paper towel in the injector hole.

I adimatly(sp) recomend NOT to buy a spare set of injectors. They will be about $500.00 for the set. But by the time you MIGHT need them, they'll be expensive paper weights in the salt air enviroment.

Bleeding of the fuel lines won't be necessary. On a Yanmar the only time you need to bleed after the injection pump is when you get water in the system.