Diesel Engineers advice needed .....

[Guest]

Engine run at various times through winter to check / change oil etc. etc. All seemed ok ... we thought we had a problem with overfull sump causing run on from lub oil getting up - but no all seemed ok.

Boat launched and engine started. All fine for about 5 mins ... then engine revved up to max. Stopped engine .... checked throttle cable etc. all appeared ok ... so adjusted idle stop screw back ... engine idling fine .... 3 - 5 mins and speeds up to max .... pull stop and engine dies ... put stop back in ... engine idles. Engine now is in state that it starts ... warms a little and idles ... then speeds up to max revs ... pull stop out and back in before it dies ... it idles again ... 2 -3 mins and back up again to max revs ..... pull stop and just before dies ... put stop back in again and it idles ....

When idling - engine sounds sweet as a dream ...

Engineer here says old diesel fuel ... but he has only listened today ... I think there is crud in the system ...........

Any diesel engineers like to suggest what it is ?

Engine is a Perkins 4-107 .... raw water cooled ... bit sticky on rings but never a problem before ....

Over to you guys ??????

 

[ShipsWoofy]

Sounds like a governor problem

 

[tyce]

governor spring weakness/ failure is a likely problem

 

[Csail]

piston rings or fuel hp pump (governer)

 

[boatmike]

There are several things that could cause this but most are fuel pump associated. If it is a CAV pump there is indeed a return spring on the pump governor piston that can either jam or break. Whatever make it is I suggest you remove the pump and get it to a good diesel fuel system repair shop. Unless you are conversant with the workings of the thing and have a scrupulously clean place to do it I would suggest you don't try stripping it yourself. It should be easy to test and repair for a shop with the right equipment.

 

[steve28]

try draining out the engine oil to the minimum level and trying it again. sounds very much like its running on the sump oil.

 

[huldah]

I understand what steve28 is saying, but if that were the case, the engine probably would continue to race when the stop is pulled.

However, it is worth checking that the oil has not been thinned with fuel. Usually the oil level will rise when this happens.

If it is running on oil, then make sure you have something, such as a cloth, to block off the air intake, should the engine go wild.

Philip

 

[Caer Urfa]

I bought a boat with Diesel that had been in the tanks for 2 years and engine started and ran fine untill I got level low enough to re-filled.
Unless you have old tanks I do not think it is dirty diesel.

Mike

 

[Guest]

[ QUOTE ]
I understand what steve28 is saying, but if that were the case, the engine probably would continue to race when the stop is pulled.

However, it is worth checking that the oil has not been thinned with fuel. Usually the oil level will rise when this happens.

If it is running on oil, then make sure you have something, such as a cloth, to block off the air intake, should the engine go wild.

Philip

[/ QUOTE ]

If running on Oil - then stop cable would have literally no effect ....... but its working normal - stops immediately.

Oil level is fine etc.

Mmmmmmmmm will be calling in Eng'r to look it all over ... again !

It spoilt a fab day ... having launched boat into my private bit of river ........ to find engine not playing game !

 

[Liz_I]

Hmm, maybe diesel bug? We experienced engine racing, then slowing, reducing revs helped. Perhaps change/examining filters. Take a 'deep' sample from fuel tank to see if there is any 'crud' or water. Just a thought. Good luck

 

[Guest]

Could it be a build up in pressure on the return line. I do not know how a 4.107 pump works but it does have a complex input regulator arrangement under the input union. Since it takes minutes to go wrong something a reasonable size has to change. It can not be heat as the stop lever could not cool the parts that quickly. So something is pressurizing above its design limits.

 

[Topcat47]

M experience of the dreaded bug is that the engine stops due to the crud accumulating around the fuel pick-up (it didn't get as far as the filter). I'd look at the governor first, too.

 

[Guest]

[ QUOTE ]
Hmm, maybe diesel bug? We experienced engine racing, then slowing, reducing revs helped. Perhaps change/examining filters. Take a 'deep' sample from fuel tank to see if there is any 'crud' or water. Just a thought. Good luck

[/ QUOTE ]

My fuel system is pretty basic and will just about let through anything ! The fuel filter was changed when the oil was done ... and it was a mass of crud ... but still worked !
Fuel tank was strirred up continuously while being sucked out - Pela used to great effect !! And all fuel filtered back through multiple layers of muslin etc. after a good syphon of tank.

The thought that crud may have worked into system - but my feeling is the governor sounds like it could be ...

The engine continues to race ... it's not up / down like a fuel feed problem ... it's just like someone has rammed the throttle to the stop and left it there. The stop button (mechanical connection to pump) is instant ... so that also indicates to me a fuel pump regulation item ....

And I was so made up with getting her in ... she looks a peach at bottom of garden ... if wind stays moderate to today - should have the mast up !!

 

[dieselforblood]

ok it may be a couple of things , the injection pump could be the main problem it sounds like the govenor is damaged , just to be sure . does the engine produce any smoke /black/blue/white . is the engine breather connected back into the intake system if so just remove this and try the engine again just in case oil mist is a factor unlikely but its worth trying it does not cost anything / but i would plum for injection pump /whip it off and get the injectors tested at the same time .
i am a mobile diesel engineer based epsom surrey
tel 07883066979
regards
steve