Nanni 3.90 HE crank no start

[nuku34]

Re replacing the injection pump using the old shims (or new shims of the same thickness):
A buddy tried this on a Bukh 20 using the old shims. For some reason this resulted in the timing being off so that the intake valves opened too soon. The engine did start, but ran so raggedly that within seconds the heavy flywheel sheared all its 5 bolts and fell into the bilge still doing about 500RPM! NOT much fun!
I would test the timing using the standard factory recommended procedure. That's not a lot of fun either, but doesn't require expensive test gear.
Just saying....

[Alapa1964]

thanks for reply
12months ago my heat exchange developed a hole and let water into pistons hydrolock.. I think this is called ..I panic and thought Id blown the head, so I took off the head and had The headguys in newcastle check it out,, they serviced the head and valves and said it was good..then I took of heat exchange and found a hole in the aluminium heat exchange ,,bought a new one $3000 through Nanni nsw..Ended up fixing new one..So Ive got a spare..Was running great until a month ago when It got hard to start replaced fuel injection pump ,,got it going for a day and hav'nt got it started since. Im in Tamworth boats in Port Stephens..

[skipperpete]

Originally Posted by Alapa1964

thanks for reply
12months ago my heat exchange developed a hole and let water into pistons hydrolock.. I think this is called ..I panic and thought Id blown the head, so I took off the head and had The headguys in newcastle check it out,, they serviced the head and valves and said it was good..then I took of heat exchange and found a hole in the aluminium heat exchange ,,bought a new one $3000 through Nanni nsw..Ended up fixing new one..So Ive got a spare..Was running great until a month ago when It got hard to start replaced fuel injection pump ,,got it going for a day and hav'nt got it started since. Im in Tamworth boats in Port Stephens..

Tamworth to Port stephens is a bit commute to go sailing, but Port Stephens is an excellent harbour and town. Hmm, I have a lot more questions now, if you like, PM me and I’ll see if I can come up with a way to get it up and running again. The leakage test will be useful, try doing it at TDC compression if you can hold the crank from turning, otherwise just take off the rocker assembly as a complete unit and let the pistons blow down to BDC as you let in the air.

[Alapa1964]

Thanks for reply ,yes 4 hours drive not ideal but them the breaks, I'll do what you said tomorrow and let you all know how I go,, thanks again..

[Shaneesprit]

Originally Posted by skipperpete

No one missed the basics and certainly not the OP...... and the 3 basics are FUEL , OXYGEN and HEAT.
He replaced the injector pump, primed the system, checked the valve clearances, replaced the glow plugs and tested em in situ , removed the manifold ( intake and exhaust)did a (failed) compression test and finally removed the head to inspect the gasket and cylinders. Using products like “Easy start” is a really bad choice unless you’re in subzero conditions, particularly with high compression indirect combustion diesel engines like Kubota and precom yanmars. The briefest of internet searches will provide more than enough photographs of broken pistons. Yeah , I know ....Cummins and Caterpillar both had ether canisters but were arranged in a way that ether could only be injected after cranking commenced.... even then it was a destructive accessory and is dis continued. Sure , on a gasoline engine ... go for it, but on a 24:1 compression diesel beware, it WILL damage the engine (and possibly the human if they spray a volatile liquid into an engine with hot glow plugs)

Sorry your mixing up your “easy start” (flammable gas from an aerosol such as deodorants or hair spray, Carb cleaner) that have low calorific value) with Ether a much higher value specialist starting system.
An engine is designed to slowly burn fuel in a controlled manner, that is literally its job, putting a gas (Not liquid) into an engine is a recognised method, not only of allowing easier starting , but also if you take it a step further can be used to reduce fuel costs and emissions (assuming you had the control system to do that)
True the easy start method will lead to early ignition and it won’t sound very nice and for a second or 2 you won’t have RPM control. But on a boat when you need to know that your engine is going to start - I wouldn’t use it unless the engine refused to start but I wouldn’t be without it either.. In fact one of the main problems with people using easy start, is that they end up using it to often and then relying on it - instead of proper maintenance to ensure the engine starts correctly.

[Alapa1964]

Hi all
Well back from boat and still confused. I tested the compression tester at a service station pumping 60psi into the compression tester an got 100psi roughly but then without pressing the release trigger the pressure fell straight away. I tried to a leak down test using a 12volt air pump 105 watt (9 amp), 150 L/Min, 0.12MPA .
.I was'nt sure if their would be enough pressure in cylinders ,,but when the valves were closed I was very hard to rotate crank shaft, lots of kick back, all cylinders, no bubbles out of heat exchange coolent on any of the cylinders.
Replaced injectors. turned of sea water cock and disconnected exhaust from heat exchange.
. tried to start motor 14volts ,,Ill try and send video .. no start ,,I started thinking that the new injector pump I installed was out of timing ? becauce the guy I bought it of told me to take out the shimes ,,I did leave the shimes in that was on original injector pump and left of the shimes that came with new injector,,maybe I should have left both off ,,? not sure..But I did get the motor started after the new injector pump was installed,, engine ran and stared up fine for two days. Then it stopped . and would crank but not start.

[sinnerman]

I am not a diesel expert. My boat has a Kubota D850 -based 3 cylinder universal diesel with which I am pretty familiar...

If the no start problem started immediately after the pump was installed, then I would suspect the pump/its installation.

If the engine was starting OK after the pump replacement then the no-start issue began to appear, (I think I remember something in your first posts about having to use the fuel "prime" bulb..(maybe a different person's post?), then you most likely have other issues.

If the no-start problem appeared immediately after replacing the injector pump, then I would suspect it is mis-installed. It could be the pin on the injector pump which slides forward-aft to increase-decrease fuel is not properly located in the slot on the governor lever. It could also be one of the governor springs became disconnected...

The D850 has a removeable side plate where you can view the injector pumps rack pin.

If he injection pump was removed and replaced, you would use the old shim to reinstall the pump. If a different pump was installed, then you (again) would use the same shim but would also verify the timing to determine if a different shim is necessary.

The shims move the pump closer (thinner shim) or further away (thicker shim) from the pump's camshaft. Moving the pump closer to the camshaft has the injectors fire earlier (advancing the timing), moving away makes them fire later (retard the timing).

attached is the troubleshooting section from the Kubota D850 manual for "no start"...

cheers

[skipperpete]

Originally Posted by Alapa1964

Hi all
Well back from boat and still confused. I tested the compression tester at a service station pumping 60psi into the compression tester an got 100psi roughly but then without pressing the release trigger the pressure fell straight away. I tried to a leak down test using a 12volt air pump 105 watt (9 amp), 150 L/Min, 0.12MPA .
.I was'nt sure if their would be enough pressure in cylinders ,,but when the valves were closed I was very hard to rotate crank shaft, lots of kick back, all cylinders, no bubbles out of heat exchange coolent on any of the cylinders.
Replaced injectors. turned of sea water cock and disconnected exhaust from heat exchange.
. tried to start motor 14volts ,,Ill try and send video .. no start ,,I started thinking that the new injector pump I installed was out of timing ? becauce the guy I bought it of told me to take out the shimes ,,I did leave the shimes in that was on original injector pump and left of the shimes that came with new injector,,maybe I should have left both off ,,? not sure..But I did get the motor started after the new injector pump was installed,, engine ran and stared up fine for two days. Then it stopped . and would crank but not start.

If I read the earlier post correctly, you tried to start the engine with the exhaust hose off at the mixer elbow to eliminate the entire exhaust system.....other than the mixer elbow...from the troubleshooting process. This usually results in a helluva a lot of smoke inside the boat but you made no mention of that, and its important. If there’s no smoke at all and you have compression ( still not established beyond doubt), the first logical possibility is lack of fuel. Have you at any point taken a fuel sample? Have you seen fuel coming out of the high pressure fuel line connection at the injector?
In the past, I’ve been on callouts where the owners had water in the fuel tanks, sometimes from leaking deck fill caps, sometimes from putting the water hose into the fuel fill and once where the owner mistakenly topped off his fuel tank with a container filled with drinking water ( alcohol was involved) . My point is that its not always easy to spot the difference between water and clean diesel , often its necessary to trickle whatever is coming out of the bleeders across my oily palm, water behaves very differently to fuel oil using this test.
Go back to basics, get a 4 litre can of clean diesel and a 5’ length of clear plastic hose and connect the hose directly to the injector pump at one end and the lowest point of the fuel container up in the cockpit. Start the fuel siphoning BEFORE connecting the hose to the barb on the injector pump, its messy but necessary to have a column of fuel with no air from your 4 litre to the injector pump. Bleed the injector pump , then spin it over till the pipes are purged up to the injectors and put a brake hose clamp on the return line so ya don’t lose all your 4 litres back to the tank

[Alapa1964]

Thanks for both replies.
I have seen fuel coming out of the high pressure fuel line connection at the injector?I am getting good fuel coming out of the top of injector pump when cranking I did smell it and it was fuel.
I did try to start the engine with the exhaust hose off at the mixer elbow to eliminate the entire exhaust system, but would'nt their only be smoke if their was ignition?
I will test fuel for water and bypass diesel tank like you said. Good suggestion

As for the injector pump shimes Ill ring the guy I bought it of and find out exactly what shimes go on the injector and if I have to do a retiming of it. I did have the engine running for two days off and on with no problem after the new injector was installed. Thanks for all Ill let you know the outcome.

[skipperpete]

Originally Posted by Alapa1964

Thanks for both replies.
I have seen fuel coming out of the high pressure fuel line connection at the injector?I am getting good fuel coming out of the top of injector pump when cranking I did smell it and it was fuel.
I did try to start the engine with the exhaust hose off at the mixer elbow to eliminate the entire exhaust system, but would'nt their only be smoke if their was ignition?
I will test fuel for water and bypass diesel tank like you said. Good suggestion

As for the injector pump shimes Ill ring the guy I bought it of and find out exactly what shimes go on the injector and if I have to do a retiming of it. I did have the engine running for two days off and on with no problem after the new injector was installed. Thanks for all Ill let you know the outcome.

“Wouldn’t there only be smoke if there was ignition”? ....Absolutely yes....... and its exactly what you should be looking for while cranking the engine with the exhaust hose off....... No smoke: No start!!
The shims are not negotiable, they determine the precise moment of fuel injection and too many shims causes late injection, no real problem with that other than maybe more smoke at idle and a quieter combustion cycle. Far more concerning is TOO FEW shims, obviously this advances the timing but far more worrying is the probability of the plunger elements hitting the delivery valve seat at the top of the stroke. Very damaging. The process of setting the injection timing on a cartridge pump like yours is relatively simple and can be checked quite easily by taking off the HP pipe leading to #1 cylinder and rotating the engine manually while watching the delivery valve nipple for the tiny change of fuel level in the nipple with a flashlight..... and checking the timing marks on the flywheel or front pulley..... checking is easy but adjusting ( spill timing)is a longer story and has been discussed and posted many times on this forum and youtube.
At this point, its worth suggesting that you be prepared for an uncommanded overspeed, no big deal if you’re ready for it but a real s##tshow if you don’t see it coming. Whenever you have an engine with helix plunger injection there’s the risk of a stuck plunger at max fuel which means ALL plungers are at max fuel.

[Alapa1964]

Back from the boat ..new compression tester ...3 cylinder Universal M-25 is also a Kubota (model d-850) reading 230PSI : standard 412- 469 PSI ......327 PSI allowable...I also found a bent push rod ..So should I first test head and valves or rebuild entire engine?
Any suggestion I would appreciate..