Diesel nightmare!

[Drains]

ZZR, you da man!
Ran up the engine today. After about ten minutes it started to falter so I jumped into the engine room with a wee AJ and undid one of the said banjo bolts. Diesel spurted out under lots of pressure.
The pressure got as far as the head of the fuel filter - the injector return pipe goes back to the top of the filter housing, through this





At first I thought it was blocked, but it's actually got a wee ball bearing in it, and I assume, not the spring that's meant to be there....
So it was seating and closing off the fuel return.

I removed it and just did up the banjo at the head of the filter, now the engine seems to be running fine.

What's it for lads - any ideas? I guess it's a non-return valve but I can't imagine why it's there.

 

[rocketron]

It's a restrictor, and meant to be there. With a Perkins, by pass as much as possible, and they also have a lot of joins, banjoes etc. They can all pose problems when they get old.

If it all gets so bad for you and you've had enough, take a hit, tell the prospective customer you have trouble bleeding it (which is true), drop your price a bit and get a caravan!. Never seen this fail: many male buyers think they know better!

You can always trust greed and cock!!!

 

[Drains]

********

The thing isn't acting as a restrictor right now, it's completley blocking off the injector return. There's nothing wrong with my ability to bleed a diesel engine.

 

[snowcat]

I would guess its to stop the diesel siphoning back through the return and air locking, The old 806 JCB I have is a pig for this and Air locks when its left for any amount of time, Mind it stops the kids starting it and going on the worlds slowest rampage around the village.

If it runs fine without and starts when left for a period of time, Id just remove it.

 

[madkayaker]

Leave I off and add it to the box of not sure were it came from for the next owner

 

[Drains]

Roger, as you've unhelpfully removed my request for rocketron to explain what he meant, I'll ask again!

Or alternatively as so far as I can tell his post was unhelpful and offensive you should remove that too. I'm not trying to cause trouble, I just want to know why I feel I've been slagged off. I'm a bit riled that I've been accused of flaming too, considering that's what I was getting.

Actually what I'd really like him to do is expand the detail re 'it's meant to be there' and ' bypass everything'.

And I'll answer the 'drop the price a bit and get a caravan' by saying that a motor boat without a working engine is a dumb barge and worth far less. The hit will be about five grand. I dont want a caravan, i want to sell the boat.
Talk of greed and cocks... What? Madness.

 

[rtbcomp]

Tell me which posts is/are unhelpful & offensive and I'll remove/edit that/those too.

 

[Drains]

It's a restrictor, and meant to be there. With a Perkins, by pass as much as possible, and they also have a lot of joins, banjoes etc. They can all pose problems when they get old.

If it all gets so bad for you and you've had enough, take a hit, tell the prospective customer you have trouble bleeding it (which is true), drop your price a bit and get a caravan!. Never seen this fail: many male buyers think they know better!

You can always trust greed and cock!!!

That one. The useful bit is, "it's a restrictor, and meant to be there". The rest is either unhelpful or abusive. Or am I missing something?

 

[rtbcomp]

I think you're missing something - I'd just take that as bit of banter, tongue-in-cheek comment.

If not, then it's only a suggestion which you can ignore if you don't like it.

 

[Drains]

Ah well, my bad. I still don't get it though.

 

[the snooper]

if the engine used to run fine with said restrictor then it could be an injector problem too much leak off which may also result in a loss of power to the cylinder/s

 

[MattF]

I still don't get it though.

The way I read it is that you ought mention to the prospective buyer that you're knocking a few bob off the price because you're having trouble bleeding the system. They'll likely jump at that prospect due to the usual bloke attitude of: 'I know how to sort that' etc., so you'll flog it at a bit less than hoped for, they'll think they've got a cracking bargain through what they class as an easily sorted problem, and they'll then have to sort the problem themselves.

 

[Drains]

The way I read it is that you ought mention to the prospective buyer that you're knocking a few bob off the price because you're having trouble bleeding the system. They'll likely jump at that prospect due to the usual bloke attitude of: 'I know how to sort that' etc., so you'll flog it at a bit less than hoped for, they'll think they've got a cracking bargain through what they class as an easily sorted problem, and they'll then have to sort the problem themselves.

Aye, but I've built and fitted out a 17 tonne Dutch barge, on my own, from scratch, and I can't bleed the engine that I installed? If I said that it would make me look like an even bigger c*** than I already am!

The boat's worth about 70K, but not with a failed engine.

 

[Drains]

if the engine used to run fine with said restrictor then it could be an injector problem too much leak off which may also result in a loss of power to the cylinder/s

The thing is it went through a phase of doing this, then behaved for about 50 hours, then did it again. The injectors were serviced only maybe 70 hours ago.

The restrictor may not be the problem, but I'll run her up again tomorrow and see what happens- she runs fine for ten minutes or so (I'll say again to anyone who's paying attention, the fuel system being bled is not an issue).

All I can find out about restrictor design is you get a wee hole to allow air out but not excessive fuel. This thing has a ball bearing, and seems to seat fully. I wonder if it has a bit missing, but the only person who seems to know anything about it just wants to banter. Thanks for nowt.

 

[the snooper]

it seems that the back pressure is building up and the injectors are struggling to open, so as you say no air in system and not a bleeding issue.

did it act up before injector service ?

 

[Drains]

it seems that the back pressure is building up and the injectors are struggling to open, so as you say no air in system and not a bleeding issue.

did it act up before injector service ?

Snoop, you have it. The injectors were serviced before the engine went in the boat, so I'd not had it running for long (long enough to know the injectors needed a service). After the boat was launched it misbehaved for a couple of days, then ran properly for no apparent reason. I can't remember doing anything to fix it...

 

[the snooper]

all you need to do is find a blockage or a rogue injector/s that is allowing way too much diesel past the seals

 

[zzr1200]

ZZR, you da man!
Ran up the engine today. After about ten minutes it started to falter so I jumped into the engine room with a wee AJ and undid one of the said banjo bolts. Diesel spurted out under lots of pressure.
The pressure got as far as the head of the fuel filter - the injector return pipe goes back to the top of the filter housing, through this

View attachment 29560

View attachment 29561

At first I thought it was blocked, but it's actually got a wee ball bearing in it, and I assume, not the spring that's meant to be there....
So it was seating and closing off the fuel return.

I removed it and just did up the banjo at the head of the filter, now the engine seems to be running fine.

What's it for lads - any ideas? I guess it's a non-return valve but I can't imagine why it's there.

I would guess its to stop the diesel siphoning back through the return and air locking, The old 806 JCB I have is a pig for this and Air locks when its left for any amount of time, Mind it stops the kids starting it and going on the worlds slowest rampage around the village.

If it runs fine without and starts when left for a period of time, Id just remove it.

As Snowcat has stated its a very basic one way valve to stop air-locking/fuel run back.

It works on the difference between the fuel supply pressure generated by the fuel lift pump and the pressure in the fuel returning from the injectors.

You may be able to free the ball up by tapping it gently backwards/forwards with a small punch, with some form of brake cleaner/release oil to clean it, or simply replace it.

In 40 years of fitting I've come across this 2 or 3 times, the excess back pressure in the return line causes the goverenor in the injection pump to shut down, hence the rough running, it can also stop the engine.

The valve should really be in the system, but I have seen a few where its missing.

PS. A local lorry breakers should have a few Perkins laying about...

 

[zzr1200]

Possible interesting links for those who deal/work with diesels:

http://www.imarksweb.net/book/lucas+cav+parts+list/