Are my diesel injectors knackered?

skyflyer

skyflyer

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I have a Westerbeke 30B 3-cylinder engine installed 1995.

Our boat is co-owned and one of my co-owners feels it may be time to replace the injector nozzles.

This begs several questions:

  1. Do the nozzles wear out
  2. If so, over what period of time, typically
  3. What are the symptoms of worn injectror nozzles
  4. is it an easy job to DIY

Thanks in anticipation
 
1. They deteriorate over time
2. 17 years seems long enough for change
3. Smokier, bad starting
4. Take them to a diesel injector specialist for refurb/recal. May be a problem to get them out the head. I don't know the Westerbeke set up but Volvos are a pain, Yanmar a joy.
 
They'll typicically do one of two things:-

1./ They will not deliver enough fuel or will deliver it in drops rather than a fine spray (so you might struggle with the engine at load)
2./ They might not close properely (meaning that fuel dribbles out between strokes).

The worst problem I've seen from No.2 was where the excess fuel ended-up in the sump. The sump gradually filled with oil/fuel mix, at when it got to a critial level, the engine started sucking-in the oil/fuel mix and running on it. The engine then ran-away with itself and destoyed itself, because there's no way of stopping it.
 
awol said:
1. They deteriorate over time
2. 17 years seems long enough for change
3. Smokier, bad starting
4. Take them to a diesel injector specialist for refurb/recal. May be a problem to get them out the head. I don't know the Westerbeke set up but Volvos are a pain, Yanmar a joy.
Click to expand...
Our Volvo injectors come out very easily. If the engine starts easily and it doesn't smoke why are you bothering? The cheapest option is to take them to a diesel specialist and get them recalibrated and the sprays checked. Not costly and some will check them while you wait. 17 years might be only a few hundred hours running for some boat engines.
 
skyflyer said:
I have a Westerbeke 30B 3-cylinder engine installed 1995.

Our boat is co-owned and one of my co-owners feels it may be time to replace the injector nozzles.

This begs several questions:

  1. Do the nozzles wear out
  2. If so, over what period of time, typically
  3. What are the symptoms of worn injectror nozzles
  4. is it an easy job to DIY

Thanks in anticipation
Click to expand...

Take the injectors to a diesel service shop who will service or replace the nozzles. Spares should not be a problem as this is a Kubota engine just like Nanni and Beta.
 
Check the oil to see if the level has increased or if you can smell diesel .
Loosen each injector pipe in turn at idle put a rag round the pipe to collect fuel and if each has the same drop in revs and the other things suggested leave alone.
 
Well she starts first time every time no problem. As far as I can see no real smoke problem.
Sounds like best to leave well alone until there is some positive evidence of a problem!
 
If its running smoothly, no injector knock, starts properly, and makes no more smoke than it used to, then leave well alone. Road vehicle injectors can easily run for 100,000 miles, and often a longer. Thats equivalent to over 16,000 hours engine time .
 
TQA said:
If the engine starting pattern has not changed and the engine is not smoking LEAVE THEM ALONE!

The worst thing you can do to injectors that are working well is to disturb them for a "service".
Click to expand...

Good advice. If you are doing some long distance cruising you could consider testing them but otherwise look for other problems first (if any)
 
If it's a Kubota, the injectors are easy to remove, though you'll need / should use a long reach socket. Being an industrial engine they are designed to be long lived. So as others say if there's nothing wrong, leave well alone.

The only time I had to take them out was due to water in the fuel and the engine ran very practically - so it was obvious. My set of 4 cost £120 to recondition plus a stern warning about wet fuel!

Just looked at the original post; noted the date - mine is a 1996 Beta (4 cylinder), now 4,600 hours and was about 3,000 hours when we had water in the fuel - dunno how that relates to your use.
 
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There is a danger that we all think of our boat engines in same way as car engines-a set of indirect diesel car injectors with say 130,000 miles on them and I would be thinking-test and recon.
Recently tried to guestimate the road milage equivalent of my 33 year old Merc OM636 without an hour meter.
Based upon what appears to be the current state of engine-clean burn and no oil use plus a guestimate of time in use;not in use;and ashore my guestimate came out at about 70,000 car miles equivalent bearing in mind that the boat did do the Med. once upon a time..
 
If it's starting well and giving enough power you only need to evaluate the total fuel cost per time against the cost of an injector service. (Green considerations aside).

Given the incredibly small engine use/time for a yacht engine compared to a car, it is unrealistic to expect the same performance. All that down time allows more water and bacteria to develop.

Add to that the fact that marine supplied diesel comes from less than optimal storage, and against Gallons/time, it is inevitably more dirty and will have a higher water content.

As far as DIY goes, you'll be disconnecting a fuel in union and a fuel return to tank banjo on each one. Then a nut that holds down a clamping plate. You then pull upwards on the injector as you twist it back and forth. Eventually it will come out. Some might suggest a slide hammer.

Easing oil will help. I use 50/50 Acetone/EP90 gear oil. That seems to get everything loose within 24 hours.

What's the rush? Forget the slide hammer!

Replacement is the reverse, as Haynes would say.

But. It is essential that you re-anneal the copper sealing washers, or buy new ones.

It is also essential that you use a good torque wrench - particularly on the hollow banjo bolts.
 
starfire said:
De-compressors ?

Blocking the air intake ? (don't use your hand)

CO2 fire extinguisher up the air intake ? (don't use powder !)
Click to expand...

I managed to stop a runaway Lister diesel some years back when I fitted a wrong direction hydraulic pump and as soon as the hydraulics were operated the sump filled with hydraulic oil and ran away. I wrenched off the air cleaner and did use my hand to stop it - does 'suck' strongly though! and filled the workshop with white smoke.........
 
Had a 30B on the last boat fitted 96, ashore for 5 years. Passed the 500hrs under my ownership and had to tighten the cylinder head bolts (every 500hrs) and they did tighten on the lowest torque setting. Also cleaned the heat exchanger and fitted beefed up end plates which i turned down from waterpump face plates. Changed the glow plugs at about £50 each and no pattern units available as the base engine is a mitsubushi lump so would do some detailed research before taking the enjectors out. Also changed the electeric fuel pump after a dose of diesel bug. If you want to do nice things for the fuel system fit a better filter system, I fitted a racor spin on.

Always started (except when the filter was completely clogged!

Fuel pump like this:
http://www.asap-supplies.com/search...ectric-fuel-pump-for-diesel-and-petrol-306550

Filter:
http://www.asap-supplies.com/search/racor+filter/racor-120r-rac-01-petrol-spin-on-fuel-filter


Good luck with it.
 
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oldharry said:
If its running smoothly, no injector knock, starts properly, and makes no more smoke than it used to, then leave well alone. Road vehicle injectors can easily run for 100,000 miles, and often a longer. Thats equivalent to over 16,000 hours engine time .
Click to expand...

Given correct maintenance little Jap diesels will easily go 20,000 hours. They have no injector service procedure.

Unless you get water though the injectors stay away from fuel pump shops.

#1 The words 'No fault found' does not exist in pump shop vocabulary.

#2 Genuine Denso or Kikki injector tips are expensive, many pump shops use aftermarket tips from China or Italy. Some aftermarket stuff is good, some not so good.
 
Bobc said:
They'll typicically do one of two things:-

1./ They will not deliver enough fuel or will deliver it in drops rather than a fine spray (so you might struggle with the engine at load)
2./ They might not close properely (meaning that fuel dribbles out between strokes).

The worst problem I've seen from No.2 was where the excess fuel ended-up in the sump. The sump gradually filled with oil/fuel mix, at when it got to a critial level, the engine started sucking-in the oil/fuel mix and running on it. The engine then ran-away with itself and destoyed itself, because there's no way of stopping it.
Click to expand...

Actually a diesel running away like that can be stopped, but only by cutting off its air supply. You have to think and act quickly. On most engines the fastest way is to put a plastic bag over the air filter.
 
starfire said:
De-compressors ?

Blocking the air intake ? (don't use your hand)

CO2 fire extinguisher up the air intake ? (don't use powder !)
Click to expand...

Easier said than done, diesel engine overrevving in self destruct mode, smoke, fumes, been there and seen it, braver men than I ran to a safe distance and waited for the bang. Con rod through the block, all main bearings and big end shells vaporised, valve gear dropped into cylinders.

Best advice, stay clear till the engine stops. then start clearing up the mess !!!
 
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