Northern Lights 9KVA Generator won't start

[Jenno]

Hi all my NL generator has problems starting when cold. It has done 600hrs. It starts when hot or when sprayed with aerostart.
I have changed the exhaust elbow, tested the glo plugs all ok, tested the injectors, all ok.
Any ideas?
The Northern Lights/ Yanmar mechanic has not been able to fix the problem.
After it starts it runs as normal!
Help!!

[Chotu]

Originally Posted by Jenno

Hi all my NL generator has problems starting when cold. It has done 600hrs. It starts when hot or when sprayed with aerostart.
I have changed the exhaust elbow, tested the glo plugs all ok, tested the injectors, all ok.
Any ideas?
The Northern Lights/ Yanmar mechanic has not been able to fix the problem.
After it starts it runs as normal!
Help!!

Did you test to see if you have a fuel system leak?

Maybe it’s a tiny one and the extra cranking gets the little air bubble worked through.

Lots of wild guessing here because it’s an odd situation. It doesn’t need glow plugs at all in warm weather. Should start right up without them.

[kmacdonald]

If it only has 600 hrs its 99.9% chance it's a fuel problem.

[Sailmonkey]

How long have you been spraying gasoline and ether into this engine?

Have you ever checked compression?

[Jenno]

Originally Posted by Sailmonkey

How long have you been spraying gasoline and ether into this engine?

Have you ever checked compression?

The compression was tested along with the injectors.
All good.
Only spraying aetostart a few times. thanks

[Jenno]

Originally Posted by Chotu

Did you test to see if you have a fuel system leak?



Maybe it’s a tiny one and the extra cranking gets the little air bubble worked through.



Lots of wild guessing here because it’s an odd situation. It doesn’t need glow plugs at all in warm weather. Should start right up without them.

Its not leaking out but maybe it's sucking air at rest.
I will take off the fuel pump and check it
Thanks

[endeavour55]

not to hard to pressurizer the fuel system from tank up. with air. that will show up a leak real quick

[Locquatious]

We have similar problems starting our 700 NL generator:

1. Replaced the glow plugs and the glow plug relay. That helped the most despite being in the tropics.

2. Replaced all batteries-starters-switches, upgraded wiring size and terminals, improved engine ground connection and even brought a jumper directly to a starter bolt on the bell housing. Did not help us. Still the generator sometimes only starts when the main engine is running and charging the batteries (to 13.7V) and when the house and starting batteries are switch-combined.

3. a. Replaced all of the fuel lines, with 3/8" flared copper tubing, leading to a primary filter system for just the generator. Installed a check valve isolating the main engine fuel supply from the gen fuel supply but also re-piped the main engine fuel lines. Added a (Kubota tractor) fuel lift pump powered via the fuel rack circuit. This may have helped some and was recommended by a mechanic and NL service engineer. If you have a leak, each cool start is also a fuel bleed.

3. b. It is recommended to install the primary filter before the fuel-lift pump. But that leaves no good way to remove air from the filter housing after a water drain or filter change. Added a bypass valve after the fuel lift pump to send air from the primary filter directly into the return line.

4. Cleaned the exhaust/mixing elbow. There was a lot of carbon and rust build-up that was constricting the exhaust water injection.

5. Ran fuel return line with a high loop at the engine before it drained back to the tank. If the injector check valve, between the injector pump and the injectors, leaks when the engine is off and there is negative pressure in the fuel supply line, air might make it's way back to the injector pump. At first it seemed to help. It didn't hurt.

6. Will install new injectors next season.

[Woodland Hills]

I had the same problem with a Kubota Block 12kw Northern Lights. After replacing glow plugs myself with no change I called in a tech. His diagnosis was that the injection pump was leaking internally allowing fuel to empty the fuel lines. It then took lots of cranking to fill them and get a start. If the engine was recently run/warm then one line would have fuel still in it and that cylinder would fire at once then the others would chime in as they filled with fuel.

Solution: have injector pump rebuilt by the local tractor shop. Now it starts as soon as it cranks over with all three cylinders firing and no glow plug needed. This generator has 3400 hrs and is going strong.

[Mike Banks]

If it starts using ether--your glow plugs are NOT working properly. They may test OK--but they are still not getting HOT. Start-Ya-Bastard and other starting fluids based on ether can be tough on engines because of pre-ignition. I prefer the flame method as described below. It uses no other significant fuel than is provided by the injector pump of the engine.

To prove this--get a piece of lamp wick and tie it securely to a piece of wire. Have a Zippo handy, then with the air cleaner disconnected, dip the wick in ethyl alcohol if you have any--but even diesel fuel will do if nothing else is available. Light the wick and hold it flaming in the mouth of the air inlet and press the starter.

If the engine starts up with the fuel-warmed air, then the fault obviously lies somewhere in your glow plugs or their possibly too thin in gauge circuit wiring. Glow plugs draw a good amount of current and need HEAVY wiring.

Check also the RELAY that actually switches on the glow plugs, not just the switch on the control panel which only operates the relay.

Make sure the relay's points are clean and making a good contact--if in doubt, replace the relay with a platinum contact or mercury type of the appropriate current value in Amps--check your workshop manual or look it up on line..

I keep such an emergency wick in the engine compartment along with a small container of ethyl alcohol. Alcohol does not smoke as does diesel, but I prefer to dip it in ethyl alcohol such as is used in spirit stoves.

A weak battery will possibly be able to swing the engine once or twice, but not while heating the glow plugs at the same time. The alcohol wick flame may save your life on a lee shore with a dying battery.

Obviously with a naked flame in the engine compartment you have to have a space clear of battery produced hydrogen and other flammable stuff- and some metal container in which to extinguish the wick once the engine is running.

[Scrimshaw4]

Had a similar problem Turned out to be non-fuel resistant Teflon tape used on the fuel filter pump fitting. Caused a minor air intake leak that ending up starving the engine / prime loss while at rest.