Fuel injection timing Yanmar 1GM10

Slinky Spring

Slinky Spring

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Continueing saga of poor starting of my 1Gm10.
What are the symptons of incorrect fuel injection timing? Once i get the engine started it runs fine.
Is it possible that incorrect timing would prevent it starting but that once it was running it would be okay?
The manual talks about lining up the marks on the fly wheel to establish whether the timing is advanced or retarded. Assuming they dont line up which side of the mark is advanced and which is retarded?
It then says that a certain thickness of shim under the fuel injection pump relates to 1 degree. How do I know what represents a degree on the flywheel.
I know it sounds like i need professional help but it is hard to find in the Lake district at weekends. Plus I want to learn myself.
Any advice welcomed.
 
Already covered your suggetions.
Head has been serviced over the winter so compression is fine. elbow is okay.
Piston height is exactly as it should be.
Spring on the governor lever has been replaced.
Injector has been checked and is okay.
Battery is healthy enough.
 
The fuel injection timing is highly unlikely to be off unless it was disturbed.Anyway from memory ,the manual says that on the injection cycle you should turn the flyweel slowly by hand while monitoring the injector tip(wich of course has to be out and connected to the fuel line)until you see fuel coming out.Don't stay too close to it as it can be dangerous and keep any body parts away. Turn the engine in the direction of rotation.If the flywheel is before the crankase mark when fuel spurts out,it's advanced.To correct the timing you have to add or subtract shimms.More shimms retard, less ,advance.
 
Unlikely to be a timing problem - have you checked the lift pump? a small hole in the diaphragm would make it difficult to start but could still pump enough fuel once the engine is running. These engines must also be bled in the correct sequence. Once you have bled it, go back and do it again - pre-filter/fuel filter/injection pump/injector...
 
I have never had any problem starting my 1GM. It is unlikely to be timing as unless you have removed the shims under the pump there is nothing to go wrong - and it would not run properly anyway. The only other possibility on the fuel side after bleeding it is the rack setting on the injection limiter (inside the big dome nut on the front of the gearcase below the injector). Setting this is covered in chapter 4 section 2 of the official manual. But again unless you have had this out it is unlikely to be wrong.

Tips for starting. Some engines seem to like some "throttle" on starting - mine doesn't except in really cold weather. Turning the engine over for a couple of seconds with the decompressor raised then dropping it also seems to work. Others on this forum have put a pre-heater in the air intake filter housing with success. (assume you have changed the intake filter - but try without it as well).

Final possibility from me is back pressure. Usually not obvious from external inspection but exhaust hose can delaminate internally and cause back pressure.

Hope this helps
 
What about the starter motor cranking speed?

2 things: 1) Ensure that all 4 terminals between the starting battery and the engine are clean ie + to + and - to - and 2) check with a clamp meter that the starter motor is recieving at least 350amps (Manufacturer's spec for a 1GM10 says upto 450amps) If you are getting 350 Amps + and the starter motor is struggling then get it overhauled: It easy to get it off - Just 2 bolts and a 10" extension + a torch. Overhaul shouln't cost more than £40 assuming that if it's not burned out then it's just a (non DIY) replacement of the brushes [Don't buy Yanmar brushes as they cost 8 times more than standard brushes for the same small tractor starter motor.]

The 3 things a diesel need are fuel, air and compression - If the starter motor is wearing out or the terminals are acting as resistors under load then you're not going to get the initial compression temperature at 15BTDC to start the engine.

FYI, a 1GM10 has as supplied a single shim between the block and the fuel injector pump: To advance the ignition remove a shim, to retard it, add another shim ..... BUT your engine will be long gone dead before you need to change the ignition advance/retard.
 
I would repeat my poor starting issues :

1. Small amounts of carbon on injector face upsetting spray pattern.
2. Crud in precombustion chamber below injector (two pieces of metal between cylinder and injector, come out with a hooked wire with the injector out)
3. Stop mechanism jamming - bowden cable kinked and jammed when stop lever returned to run, leaving stop mechanism partly operating.
4. Battery voltage low after starting but battery good. Alternator can drain enough power on a cold engine to stop it if the battery voltage is low and the battery is low resistance (good) . Saildrive versions have delay on alternator field energizing to allow engine a couple of minutes to warm up.
5. Not engaging 100% throttle on cold-start days.

I spent years believing there was something wrong with my 1GM until I took it for a whole day to Marine Power , gave them 600 quid for a day's labour (valves and clean-up) and they proved to me it was then 100% as it should be.

Since then I have decided to accept it more and now can identify the problems above when they occur.

Especially as after the engine had been looked at in the past I ended up with hot sea water dribbling over the alternator out of an incorrectly torqued down cylinder head, which fortunately leaked _out_ rather than _into_the_cylinder_.
 
when your cranking it over does it sound like its trying to fire or nothing obvious?

Do you have an electric soldering iron that you can use onboard ?, if so try removing the air cleaner and laying the iron in the intake for a couple of mins and then try starting again.
 
Fuel filter has been changed.
Rack adjustment has not been touched.
Lift pump has been opened up and diapragm checked.
Tried fitting a preheater in the form of a glow plug as suggested by others without any obvious benefit.
Checked the piston height to check for bent con rod but it was exactly as it should be.
Engine was taken out to work on over the winter so problems existed when not connected to the exhaust hose so unlikely to be that.
Any other suggestions gratefully accepted /forums/images/graemlins/confused.gif
 
I am in the same boat (pun). My port engine is dead, it has been getting progressively harder to start over the last few months.

I followed the fuel through to the high pressure line which is pulsing away nicely when I turn the engine over. This weekend I swapped the injectors over from one to the other, the stbd engine with the port engine's injector is now starting as it did, port is still dead.

The strange thing is, when I back off the return fuel banjo it stays dry as a bone, doing this on the starboard engine has fuel bleeding out of it, I was convinced this was a blocked injector, but obviously not. Someone has suggested the injection pump may not be giving enough pressure to open the injector nozzle. I am all for swapping more and more bits, but once shims are mentioned I am getting a man in for an opinion. I have the full blown manual, the fuel system makes frightening reading, I am happier stripping petrol engines to be honest.

I will report back if I get an answer before you are sorted, it sounds like we have similar problems.
 
Running out of ideas. But 3 things.
Did you run it out of the boat without the exhaust and still have difficulty starting?
Have you tried my suggestion for turning over with the decrompression lever up, then dropping it? I sometimes do this in very cold weather, partly because it gets the oil circulating and partly because it eases the load on the starter motor.
Finally, have you had the starter motor checked and then the current at the starter motor when turning? although the battery may be fully charged there may be loss in the cabling.

Can't think of any other possibilities
 
Here is where I am at...

After speaking to the Engineer, Rob Walker at HMES Pwllheli he immediately suspected the exhaust, oh the Achilles heel of the 1GM10.

He suggested from what I had tried and the fact the engine felt like it had compression, though when I thought about this, my swmbo was the one who turned it over.. I forgot to take into account that she is a girlie. I can turn a 9hp diesel over just, I doubt she could.

So low compression. Rob suggested that the 1GM10 is renowned for taking a gulp from the exhaust when you shut down, if your levels are bad and no water lock fitted this can mean any water left sat in the down pipe gets sucked back up. I was confident that my installation should have meant this can't happen, steep down hill to the water lock and then up and out.

But..

If the exhaust elbow breaks, things are not so rosy. Inside the 1GM10 pipe is a sleeve to direct the water away from the manifold joint and thus the cylinder head.

Here is what I found.
exhaust01.jpg


As you see the sleeve which is meant to be welded to the manifold has broken away. Here is is alongside the down pipe.
exhaust02.jpg


Here we see the water inlet from the outlet of the anti-syphon valve. Note the proximity to the manifold, I found the sleeve inside the rubber pipe near to the water-lock. This meant water was pretty much gushing into the exhaust valve guide.
exhaust03.jpg


So I took the head off, and sure enough the exhaust valve was ruined (corroded), the pre-combustion chamber had rust all over it, the top of the cylinder was pitted with rust. Rob is now reworking the head, at least when it comes back from the shop, new guides and a good clean, new valves, new gaskets, exhaust to be welded.

Oh joy. Well, he thinks I may have it back by this weekend, so there is the silver lining.

I was surprised how easy the engine is to strip, this is a 5 year old motor, I am more used to this intensity with old high mileage cars, it was rather nice that bolts just undid without hassle.

Why am I writing this, well, if you start to have starting problems, or maybe even as part of routine maintenance, I would now suggest, inspect that weld on the exhaust, don't leave it like I did, it could mean a new head, mine has not corroded past the surface, but it could have done.

Hope this helps.
 
Slinky Spring said:
Continueing saga of poor starting of my 1Gm10.
What are the symptons of incorrect fuel injection timing? Once i get the engine started it runs fine.
Is it possible that incorrect timing would prevent it starting but that once it was running it would be okay?
The manual talks about lining up the marks on the fly wheel to establish whether the timing is advanced or retarded. Assuming they dont line up which side of the mark is advanced and which is retarded?
It then says that a certain thickness of shim under the fuel injection pump relates to 1 degree. How do I know what represents a degree on the flywheel.
I know it sounds like i need professional help but it is hard to find in the Lake district at weekends. Plus I want to learn myself.
Any advice welcomed.
Click to expand...


Yes but so will air in the system, low compression etc....

Loosen the fuel injector nuts a couple of turns and turn the engine over on the electric start to loosen the injector.
remove injector and reattach it to the fuel pipe MAKING sure it is not pointing anywhere near any part of your or any other person.
remove the starter motor
using the starter handle OR socket on crankshaft slowly rotate the crankshaft CLOCKWISE until the injector timing mark (plain line) lines up with the pointer on the bell housing (keep a hand over the injector hole the first couple of turns in case the pre-compression chamber pops out).
The injector will 'fart' when it activates.
If the injector 'fires' early add shims under the fuel pump/ late remove shims. Repeat until correct. Simples!
 
Not sure why you replied to a 5 year old thread, particularly as you do not seem to have read the OPs final post where he explained in detail what was wrong and how he fixed it - and it was nothing to do with air in the fuel system.
 
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