Flipping engine won't start

[pmagowan]

Is it old fuel? At the end of the day diesel engines tend to be quite simple. If it turns over then electrics are generally fine. Then you need clean fuel and compression to get it to fire. It almost always comes down to fuel. Either a leak in the fuel pipe, a clog, contamination etc. It shouldn't be too difficult to pin it down. You can 'feel' compression when you turn the flywheel or you can loosen an injector to decompress a cylinder. I only speak from experience and some amateur engine rebuilding, just be systematic and you will generally find the problem.

 

[richardh10]

If you keep turning the engine over make sure you aren't filling the exhaust with water, it could end up back-filling into the exhaust valves depending on the geometry of your installation.

Ah, now that sounds like a possibility. When I take the air outlet off and turn it over, I can hear water bubbling. Could that be it? And if it is, how do I sort it?

 

[sailorman]

Ah, now that sounds like a possibility. When I take the air outlet off and turn it over, I can hear water bubbling. Could that be it? And if it is, how do I sort it?

turn the seacock off

 

[ghostlymoron]

After two years out, there may be a fair amount of water in the tank (caused by condensation). Check the bowl on fuel filter if you have one and bleed some fuel into a jar and let stand.
If the engines not spinning as fast a usual, you may have a poor connection check them all.

 

[Redwing228]

When the engine is cranking is there anything coming from the exhaust? - i.e. if the fuel is injecting but not firing you may see the white vapour of unburnt fuel. If the engine is firing you will hear it knock and see the 'smoke' becoming greyer and darker before it may eventually start.
If there is no smoke or vapour coming from the exhaust then there is probably no fuel being injected. Another check for this is to crank the engine slowly by hand and you should hear the injectors make a 'creaking' or 'squeaking' sound. Try this with the fuel 'on' and the rack at full speed setting. Cracking an injector line at the injector will prove that fuel is getting there. Otherwise, remove an injector and reverse it on the line so it faces upwards and being very careful, try cranking again to see the fuel spray.
I got this far with a Petter twin with the same problem only to find that the injector valves were gummed up solid after a long period laid up.
Hope this helps,
Bill

 

[John 32i]

Ring Anthony Kettlety 07887 620830 - often around SYH and the Orwell
Very knowledgable chap and reasonable rates!

 

[alan17]

Cimo - thanks for that.

Definitely got fuel to the injectors.
Air intake ok
Will check the stop solenoid
Will check govenor cable set up
It's cranking just about ok, but not really what I would expect from a new battery
Haven't checked the valve clearances, but should learn how to do this!
Can turn it by hand, and there seems to be enough compression.

I can't believe it can be anything too serious, but I just can't work out what it actually is. I will certainly let you know

If you can turn engine over by hand and feel the compression then it is probably lower compression than that which is needed! Can you borrow a compression gauge to get an accurate figure. When I last tried a diesel engine by hand I found the compression so great that I could barely rotate the engine unless the decompression levers were used.

It seems likely to me that during storage the piston rings have become seized within the grooves in the pistons resulting in poor compression. If this is the case you will need to get the engine spinning fairly quickly to have any chance of starting. If you do get it started keep in running for at least 30 mins to get the engine hot and free up the rings. I wish you good luck.

 

[macnorton]

pour a little clean engine oil in the air intake (egg cup max), turn the engine by hand a couple of times. Brake dust cleaner will help start an engine without the problems associated with cold start but don't get carried away with it.

If that fails rig up a 24v supply to the starter which will start it if you have fuel at the injectors, don't forget to isolate everything else electrical though!

 

[pampas]

No oil around rings is another possibility, squirt some oil in each cylinder and see if it improved the situation.

 

[oldharry]

Cimo - thanks for that.

Definitely got fuel to the injectors.
Air intake ok
Will check the stop solenoid
Will check govenor cable set up
It's cranking just about ok, but not really what I would expect from a new battery
Haven't checked the valve clearances, but should learn how to do this!
Can turn it by hand, and there seems to be enough compression.

I can't believe it can be anything too serious, but I just can't work out what it actually is. I will certainly let you know

Cold engine cranking too slowly = bad starting. Check particularly the earth negative return connections. Easy way is to crank it for about ten - fifteen seconds, and see if any connections get warm. Also a temporary fix is to give the connections a squirt of WD40. Once the stuff dries off it reverts to slow cranking, but proves the fault.

I had a Bukh 20 which had been in store for about 2 years, and just didnt want to know. In desparation I kicked it with a whiff of Easy Start. It instantly leapt into life, and always started perfectly after that. NEVER use it again! Its an engine wrecker, and whatever they say, engines get 'addicted' to it - it can take months to get the engine back to starting normally without it once that happens. I have also known it blow holes in pistons, bend or even break con-rods etc. Bad stuff....

 

[NickRobinson]

No oil around rings is another possibility, squirt some oil in each cylinder and see if it improved the situation.

Important- if you dose the cylinders with any liquid, (diesel, lube oil etc.) hand turn before using the starter to ensure you don't hydraulically lock it and do damage.

Make sure you are able to refit injectors after removal- some have tricky sleeves with water behind, almost all are going to need new seals. (and some are never going to come out anyway without factory pullers.....)

Another vote for emergency use of Easy start (BTW, it's ether, so if it does not work, you can dull the pain )

Nick

 

[sailorman]

Cold engine cranking too slowly = bad starting. Check particularly the earth negative return connections. Easy way is to crank it for about ten - fifteen seconds, and see if any connections get warm. Also a temporary fix is to give the connections a squirt of WD40. Once the stuff dries off it reverts to slow cranking, but proves the fault.

I had a Bukh 20 which had been in store for about 2 years, and just didnt want to know. In desparation I kicked it with a whiff of Easy Start. It instantly leapt into life, and always started perfectly after that. NEVER use it again! Its an engine wrecker, and whatever they say, engines get 'addicted' to it - it can take months to get the engine back to starting normally without it once that happens. I have also known it blow holes in pistons, bend or even break con-rods etc. Bad stuff....

a small squirt of engine oil in the inlet manifold will do the same job

 

[Buck Turgidson]

As someone already stated, after 2 years your fuel will have stratified. Check the fuel quality.

 

[richardh10]

Many thanks all for the very welcome advice.

Next to check are the valves and/or the injectors. Fuel is definitely getting through, but I hadn't considered that it might have gone off.

I'll keep you posted

Cheers

 

[sailorman]

Many thanks all for the very welcome advice.

Next to check are the valves and/or the injectors. Fuel is definitely getting through, but I hadn't considered that it might have gone off.

I'll keep you posted

Cheers

i wouls leave the tappets & injectors alone. It ran prior to lay-up, nothing has changed since. So why adjust what hasnt changed, it will be another thing then to recheck. I have had injectors in a car with 230.000 on the clock & injectors never removed

 

[PCUK]

Have you disconnected all the injector pipes to ensure neat fuel is coming out. You can have fuel at the injectors that is full of air.

 

[jakeroyd]

Assuming its got decompressors , try operating the decompressors whilst cranking to allow the crank to get up to speed then drop the decompressor lever whilst continuing to crank.

Often starts a slow cranking engine.

 

[mtb]

Plus one

If you can turn engine over by hand and feel the compression then it is probably lower compression than that which is needed! Can you borrow a compression gauge to get an accurate figure. When I last tried a diesel engine by hand I found the compression so great that I could barely rotate the engine unless the decompression levers were used.

It seems likely to me that during storage the piston rings have become seized within the grooves in the pistons resulting in poor compression. If this is the case you will need to get the engine spinning fairly quickly to have any chance of starting. If you do get it started keep in running for at least 30 mins to get the engine hot and free up the rings. I wish you good luck.

 

[sailorman]

Plus one

[It seems likely to me that during storage the piston rings have become seized within the grooves in the pistons resulting in poor compression. If this is the case you will need to get the engine spinning fairly quickly to have any chance of starting. If you do get it started keep in running for at least 30 mins to get the engine hot and free up the rings. I wish you good luck.]

oil in the inlet will assist that too

 

[david_bagshaw]

Dont waste time changing the fuel, I have used without any problem diesel that was over 10 years old.

Would definitely agree with the need to oil the rings, to aid compression. Usually the creak from the pump and injector will tell you it is working.