KAD43 problem - Part Two

msimms

msimms

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Thanks to all who commented on my earlier thread. I ran through some of the suggestions yesterday:

  • Flow back to the tank looked to be okay and the same volume across the engines. At least at tickover. No bubbles were present.
  • A sample of fuel from the bottom of the tank was drawn up and contained no water.
  • Supercharger came in and disengaged at the correct revs.
  • There was no blow by pressure detected when the oil filler cap was removed.

I've pulled the injectors and will take them for test next week. All injectors came out okay using the volvo tool other than number six which was tighter. Once out it was evident why. See image showing the corrosion on the body with one of the others as comparison. Don't know why this one should have suffered as there was no evidence of water on top of the engine. The fit is so tight I can't imagine water could have found it's way in from the top anyway.

Anyone seen this before?

Cheers

Mark
 
Mark,

When were they out last?

The one on the left looks far too clean ;)

When mine were pulled (500hours) they probably never been done before and all looked a lot worse than the one on the right.

Check was free at my local bosch shop (mb), quote from Volvo to service was ~ £100 each plus vat etc. I got mine done at www.mbfuel.co.uk in southampton (~£46 each inc vat)

Fantastic job and real improvement when I had them serviced.

Ajay
 
Have also seen a lot of fuel valves with rust. The water can come from cleaning or condense on the surface. To get rust you need oxygen and that means the sealing is not ok on this! It can be water from the engine cooling system but if you don’t have had any consumption the water is treated so you don’t get any big attack! Just brush away the rust and get them tested!
Don’t think this is(the rust) the reason for your missing power anyway

I’m interested in the procedure to test them! This is two stage nozzles. I tried to adjust mine but it was very hard to se this two steps. The guys in the local diesel workshop said: Just change them. We don’t know how to adjust them either!

This was stanadyne slim type nozzles for a ford engine!
 
ive seen in both the bosch shops ive been to a test jig for testing these type of injectors, it basically just builds fuel pressure and then the measure the spray pattern somehow (im guessing the liquid they passed through is diesel)

Other thing is they will usually test for free and then tell you what needs doing.
 
ajay said:
Mark,

When were they out last?

The one on the left looks far too clean ;)

When mine were pulled (500hours) they probably never been done before and all looked a lot worse than the one on the right.

Check was free at my local bosch shop (mb), quote from Volvo to service was ~ £100 each plus vat etc. I got mine done at www.mbfuel.co.uk in southampton (~£46 each inc vat)

Fantastic job and real improvement when I had them serviced.

Ajay
Click to expand...

That's somewhat comforting!

The boat's 2001, around 425 hours and I don't think they've been pulled before!

Taking them for test on Wed and am hoping that one of them needs some attention.
 
ulyden said:
I’m interested in the procedure to test them! This is two stage nozzles. I tried to adjust mine but it was very hard to se this two steps. The guys in the local diesel workshop said: Just change them. We don’t know how to adjust them either!
Click to expand...

Hi,

These aren't two stage, they only have a single spring, not the two found in dual stage. They were tested today and all failed with one getting a 'nearly working' comment.

The machine, which was hand operated, looked to simply build up a pressure in to the injector until it 'fired'. There may have been more than that happening behind the scenes.

There was an okay looking (to me) spray pattern but it was occuring at a low pressures. Spec stated 280 bar but mine were letting go around 230 to 240. They were also - barring the one that nearly worked - firing silently. The Engineer put a good injector in to the machine as a demonstration and it injected with a much more business-like pressure releasing sound (popping type noise). Mine were positively feeble in comparison.

They're going to be re-conditioned. Haven't yet heard back whether a clean and re-shim is going to restore or if new nozzles are needed.

As they all failed, rather than seeing a single failure I don't suppose this will be the cause of my problem and I'll need to look further.

I suppose I'm also going to have the injectors out of the other engine as they'll probably be the same. Long periods of idling/low revs apparantly causes this. As the boat spent the first part of her life (250 hours) on the Thames I'm guessing that's where the damage occured.

Cheers

Mark
 
msimms said:
Hi,

These aren't two stage, they only have a single spring, not the two found in dual stage. They were tested today and all failed with one getting a 'nearly working' comment.

The machine, which was hand operated, looked to simply build up a pressure in to the injector until it 'fired'. There may have been more than that happening behind the scenes.

There was an okay looking (to me) spray pattern but it was occuring at a low pressures. Spec stated 280 bar but mine were letting go around 230 to 240. They were also - barring the one that nearly worked - firing silently. The Engineer put a good injector in to the machine as a demonstration and it injected with a much more business-like pressure releasing sound (popping type noise). Mine were positively feeble in comparison.

They're going to be re-conditioned. Haven't yet heard back whether a clean and re-shim is going to restore or if new nozzles are needed.

As they all failed, rather than seeing a single failure I don't suppose this will be the cause of my problem and I'll need to look further.

I suppose I'm also going to have the injectors out of the other engine as they'll probably be the same. Long periods of idling/low revs apparantly causes this. As the boat spent the first part of her life (250 hours) on the Thames I'm guessing that's where the damage occured.

Cheers

Mark
Click to expand...
Hope your engine is ok now! Sorry I thought that most nozzles were two stage on hi speed diesel. My Ford 425FSD has it my BMW 520 has it and KAD 44 and KAD300has it! But I checed KAD42 and 43 has one stage.

I test nozzles regulary and my oppinion is that some nozzles are sinking in pressure due to wear on the seat that changes the area ratio that lift of the needle! I have tried opening pressures from 180bar(By accident) to 750bar witout any sigificant cange in performance! Higher pressure gives less smoke at low loads, later dynamic timing and higher pressure in the pump! Onely nozzles that are leacing or the spray is disturbed makes difference in performace! (This is on larger engines)

This sound you are referring to. A dog bark? You often don’t get it on older nozzles! It’s also important to check the pressure drop from 90% of opening pressure to about 30%.Leakage test! Manufacturer specify pressure range for this test! The nozzle can be leaking in sealing surfaces or the valve has cracks!

But I know they can make a difference. My colleagues was on a ship with engine trouble. The engines were worn out! So he made a compleate overhaul. Still the engine was not working! The nozzles looked like new but he tested them! Spray was like hell. Then he discoverd what the Philippines ment by overhaul! They brushed the nozzles on the outside!

One more thing! The fluid in modern test applications for nozzles is not diesel.
It’s an oil with similar viscosity. Less smell and less toxic!
 
ulyden said:
Any news?
Click to expand...

Not really.

I had the injectors refurbished by a local company for £18 each and have refitted them. Before I put them back I had a local Engineer perform a compression test. Pressures were all at 28 Bar except #5 which was a little higher at 30 Bar.

Weather hasn't been that great so haven't managed to get out and see if the refurbished injectors have made any difference. Maybe this weekend will be better; if not I may add some extra mooring lines and try testing on the pontoon.

I'll update after the test.

Cheers

Mark
 
msimms said:
Not really.

I had the injectors refurbished by a local company for £18 each and have refitted them. Before I put them back I had a local Engineer perform a compression test. Pressures were all at 28 Bar except #5 which was a little higher at 30 Bar.


Mark
Click to expand...

Cheaper than new nozzles for new engine types! You have to change compleete valve!


The compression test was better than volvo says 25 bar /240rpm cs. If you have a lot of soot in combustion chamber you should run it for some time at 90% and 95% speed before you test the max speed. Just to blow out the soot!

If the nozzles have made a lot of soot the oil filter get clogged earlier!
 
msimms said:
Not really.

I had the injectors refurbished by a local company for £18 each and have refitted them. Before I put them back I had a local Engineer perform a compression test. Pressures were all at 28 Bar except #5 which was a little higher at 30 Bar.

Weather hasn't been that great so haven't managed to get out and see if the refurbished injectors have made any difference. Maybe this weekend will be better; if not I may add some extra mooring lines and try testing on the pontoon.

I'll update after the test.

Cheers

Mark
Click to expand...

For 18.00 each there is no way you had new nozzles fitted there at least 50.00 each nozzle plus fitting and calibration checks.

Maybe you just got a test and pressure reset for that money.

Compression is good though, I have a tamd41 in bit today, comp test only showed max 230psi worst was 100 psi, removed pistons to find blowback past rings on all pistons, so its a full piston and liner job to make good.
 
volvopaul said:
For 18.00 each there is no way you had new nozzles fitted there at least 50.00 each nozzle plus fitting and calibration checks.

Maybe you just got a test and pressure reset for that money.
Click to expand...

They didn't need to fit new nozzles, they were cleaned and reset. He told me that if he couldn't get them in to spec and they needed new nozzles I'd be looking at adding about £20 - £30. Luckily that wasn't the case!

Following yours and others advice and following the workshop manual, I removed and replaced the injectors myself. I bought the removal tool as I didn't want to risk pulling the copper insert. A Chichester based Engineer came and cleaned out the copper inserts and performed the compression test as I don't have those tools.
 
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