Engine not Reving?

[G.Mac]

Alright there folks,

It appears that we may have a problem with our engine as it only revs to 1700 rpm instead of 2600rpm.
My brother Andy conacted Mermaid and their initial guess was that the wrong fuel filters had been fitted so he bought and replaced the 3 fuel filters on the engine but to no avail. The engine appears to be getting full throttle so that leaves us thinking its either the Turbo or the Fuel pump that may be goosed, both expensive items unfortunately.
I was wondering if anyone who had more experience of these engines and their quirks may wish to comment on our problem and steer us in the right direction?

Oh yea the engine is the 204hp turbo 4

Graeme

[doggypaddle]

I am not familiar with this particular engine, but assuming its a standard non electronic diesel, here is what i would check first after changing filters, although you probably allready know/done most of thisdoes it smoke a lot under way?black smoke, too rich, lack of air or overfuelling,blue smoke, engine oil, suspect turbo seals or rings/valve guides.white smoke diesel, extreme overfuelling or low compression, bad injector, usually causes obvious missfire.does it rev up to 2600 off load?(if not broken govenor spring is not unheared of or even the stop adjuster come loose not allowing full travel on the cable)If its does rev off load and its just down on power under way, check if the injector pump has a compensator. this is a diaphragm that increases fueling with boost pressure, if this gets split then you wont get the fuel to match the boost also check the pipe from the manifold to the compensator.A dodgy lift pump can also lower the fuel delivery on bosh ve pumps.also you could pull the intake hose off the turbo and check its free to spin, and not got too much play, also check none of the turbo hoses have blown off loosing boost.another possibility of aparent lack of power could be the hull cruddy?cant think of anything else at the moment.

[m chappelow]

once had problems with an underpowered diesel and fault was as doggy paddle just said it was the engine stop lever and cable that was not getting full travel ,hence the stop was at half cock when in running position ,it would stop ok but would not give full fuel when running fast , also how about wrong grade of engine oil could be too thick though it may not turn over fast or start, does the turbo have an oil feed pipe thats blocked and the turbos siesed up.

[doggypaddle]

if the wrong grade of oil was causing this it would have to be seriously thick.
eg gear oil 90 weight, that said hot 90wt gear oil is very thin as its a monograde, so its unlikely to be the problem. of course if a cold engine was revved with gear oil in it it would do serious damage before the thick oil got where its needed. also the ep additives in gear oil eat babbit bearing material, really not good in an engine.

[G.Mac]

Cheers for the feedback folks.

It does not help being a couple of thousand miles from home, but I got an email from my brother today saying that he has been in communications with Mermaid and they reccon its now the fuel pump seeing as the filters did not cure the problem
So Andy ordered a fuel pump and has fitted it and the revs have increased to 2100rpm but the turbo does not feel as if it is spooling properly. When he got the boat out the water this was confirmed by the black residue on the arse end of the boat.
Next step is to remove the turbo, strip it and clean and see what happens. Upon initial inspection there seemed to be a reasonable coating of oily residue on the inlet to the cold side so it may be gunged up. He was saying that the turbo looks similar to an old Garrett T2 unit, so if it is it will be easy and reasonably cheap to get new guts and or modify the turbo, so he will be busy counting and measuring blades over the next couple of days.
On another note he also ordered new seals for the oil cooler as it was weeping, but when he went to fit them he found that the housing is corroded so back off to Mermaid to order a new oil cooler too!!!


Oh the joys of an old boat that has not been run for some time!!!!

Will keep you updated

Graeme

[doggypaddle]

the turbo wont stop it revving to the correct governed speed off load.i would say the throttle stop on the injector pump should be wound out until the engine revs up to around 2850-2900 rpm off load. this will allow for govenor run out, so maximum full load rpm will be around 2-300 rpm lower.If the turbo isnt siezed then its unlikely to be the problem, if it has a wastegate that could be stuck open?you could have a chicken and egg situation here ....the turbo wont create any boost if there is insuffecient fuel delivery, and if it has a compensator diaphragm, the injector pump wont start to deliver extra fuel until there is some boost building up!if i was close i would come and have a look! as nos will confirm i am quite good at getting diesels to fly!

[G.Mac]

Many thanks,

I have emailed him all of your info with a link to this thread.
I will be home Saturday night so that should make things easier as I wond be dealing with 2nd hand information so will be able to post exactly what we have been trying.

All the best

Graeme

[Pete7]

If the turbo has been leaking oil then the air cooler is going to be a right mess. Good news is that it all comes apart and fits nicely in SWMBO dishwasher

Their is a wiring block on the FIP, if he puts 24 volts across it then the rack will fully open and give 100%

Pete

[G.Mac]

Screwed out the screw on the govenor? as pointed to by the red arrow



by one and a half turns and now the engine revs to about 2500 rpm under load and the turbo is now spooling up.

When you put the stick right down she will rev to 2000rpm, then drop back down to 1800 rpm before creeping up to 2100rpm where the turbo starts to spool. She will then rise to 2400rpm and slowly creep to 2500 rpm

This is only good if your going in a strait line with no waves as you cannot "jag" the throttle as the response is piss poor to say the least which is no use for any sort of wave work.

The exhaust hose decided to blow its self apart so further runs were aborted and the boat recovered.

Mermaid have sugested checking the valve clearences so will be doing that once Andy gets home from the rigs.

getting better but still not right

Graeme

[Channel Ribs]

Originally Posted by G.Mac

The exhaust hose decided to blow its self apart so further runs were aborted and the boat recovered.

Sounds like you have a nice winter project coming up, I am sure you will have a sound engine by the end of the process.