D1105 Rebuilt - now won't run.

[Mike.R.B]

Hello all,

I have rebuild my D1105 engine due to worn cylinder rings. It's had a .5mm oversize rebore with .5mm oversize pistons and rings.
It will burst into life after turning over for a while (10 or 15 cranks), but will then cut out straight away. Then it will need turning over for a while again and then do the same.

When I turn it over after it cuts out, there is no smoke coming out of the exhaust ports at first, then more smoke on every crank until it fires then stops.
I've tried a different injector pump from another D1105 but it does the same thing.
Also tried a different lift pump and there is a good return flow to the tank.
All three injectors are spraying well when connected to the pump externally.
All timing marks have been checked, and reset.

I'm running out of ideas so any suggestions would be appreciated.
The engine kind of went to the bottom of the priority list so it's been a while since I did any work on it, so I might have forgotten some information.

 

[Jim L.]

First thing which comes to mind is the cylinder pressures.

Valve lash set-up.

 

[Mike.R.B]

First thing which comes to mind is the cylinder pressures.

Valve lash set-up.

Are you saying that the cylinder pressure is pushing back through the injectors? This is a hunch I have about it.

I'm pretty sure it's not a low pressure problem and more of a fuel starvation issue.

It has new valves that I have lapped the head.

 

[Mike.R.B]

Valve clearances have been set to specification.

Fuel cutoff solenoid is working fine.

 

[200mph]

Considering you've been pretty thorough in your diagnostics, don't assume anything. Data is important and why someone recommended verifying cylinder pressure in all cylinders. Some folks have received the wrong parts or didn't get the valve/ring sealing they assumed they had causing hard starting.

I'm not saying this is your problem, but one cannot assume it is ok when troubleshooting. Verify and move on to the next system.

Good luck and hope it is something simple and inexpensive.

 

[Jim L.]

Are you saying that the cylinder pressure is pushing back through the injectors? This is a hunch I have about it.

No, just looking at big three. Air OK, fuel getting in at right time and amount with spray pattern, and heat of compression.

Without compression, it is not going to fire off. If it is lack of compression, then could be valve lash, the new rings, valve seating, etc.

 

[Mike.R.B]

What I'm struggling to say is that after it fires then cuts out, it's taking a while for the fuel to get there again. I would crack the injector pipes open and it takes a few cranks to get fuel splattering out again.
It's like the ignition pressure is pushing gasses back through to the fuel line, if that's possible somehow? I don't know.

I was hoping to refresh my memory with it all but I've just had a look in the shed that the engine is in and there's a bloody great big wasp nest above it. I've given it a squirt of nest killer so that should take effect soon.

Unfortunately I don't have a pressure tester, I'll see if I can borrow one off a neighboring farmer.

 

[Henro]

What I'm struggling to say is that after it fires then cuts out, it's taking a while for the fuel to get there again. I would crack the injector pipes open and it takes a few cranks to get fuel splattering out again.
It's like the ignition pressure is pushing gasses back through to the fuel line, if that's possible somehow? I don't know.

I was hoping to refresh my memory with it all but I've just had a look in the shed that the engine is in and there's a bloody great big wasp nest above it. I've given it a squirt of nest killer so that should take effect soon.

Unfortunately I don't have a pressure tester, I'll see if I can borrow one off a neighboring farmer.

Forgive the amateur question, but would not the fact that the engine does start and run a very short time indicate that there must be enough compression developing?

If so, is there some way compression could be lost after the start only to return after the engine stops?

It sounds like the OP is trying the engine with the exhaust manifold off since he mentions no smoke, some smoke, then much smoke coming out of the exhaust ports when it finally starts. Is there a message here?

To the OP, is there some way you could have damaged the injectors or pump during the rebuild process?

Was the tractor operating normally more or less before the rebuild. What were the symptoms that caused you to rebuild the engine?

 

[RCW]

Is the engine currently mounted in a tractor, generator, etc., or is it on a stand by itself?

If it's on a stand, how is fuel being fed to it when you try to start it?

Many applications require a low-pressure lift pump to feed fuel to the Injection Pump. If the engine isn't installed in something, you would want the fuel supply above the engine to make sure there is a little head pressure on the IP.

 

[JPB7745]

Are you sure all pistons went back in the correct cylinder I know the D950 engines #2 piston stroke was just a tad bit longer than the #1 and #2.

 

[JPB7745]

Are you sure all pistons went back in the correct cylinder I know the D950 engines #2 piston stroke was just a tad bit longer than the #1 and #2.

sorry #1 and #3

 

[armylifer]

I am by no means a diesel mechanic but it sounds to me like there is air in the fuel line. The symptom that you describe is exactly what I experienced after changing my fuel filters. It took several attempts to clear the air out of the fuel lines and get the engine to stay running. Even after fuel was spurting out of the injectors the first time I cracked each one, I had to go back and crack them each one more time and then the engine started right up. The question I ask is; have you tried cracking the fuel injectors and see if that clears up the problem?

 

[Mike.R.B]

The wasps have all died so I did some more investigation on the engine.

The timing is spot on with all the dots matching up, as you can see by the picture.
I did however find something strange; I took out the glow plugs to take away compression, and turned the engine by hand.
It seems that the cams for the injector pump are firing in between the ignition and exhaust cycle (between bang and blow). I would think they would fire at the same time that the air intake valve opens on the intake cycle. I'm not sure what's going on.

The pump cam is top right. It has a bolt on it with an alan key fitment, does this allow for tuning of the cams? I'm just wondering if someone has had the engine apart and didn't line the up the dots so has just adjusted the cam with this bolt. Now I've put it back correctly, it's now out of time. If that makes sense?

What do you guys think?

 

[armylifer]

Now I am in learning mode. I hope that someone can answer your question. BTW, I would bet that North Idaho Wolfman could answer it for you.

 

[Mike.R.B]

Henro - the rebuild was due to really bad blowby so I thought it time to give it an overhall.
The engine is actually on a generator. Which is a backup generator for my off grid electricity system, it's used in the winter to charge the batteries when there isn't enough sunlight for the solar panels. So I need it to be running reliably for the winter.

JPB7745 - I'm pretty sure they all went back in the same place. I mark everything that comes out, and from what I remember they have numbers stamped on the conrods.

Armylifer - I've done tonnes and tonnes of bleeding with no improvement. Infact with the fuel line taken off the injectors and cranking the engine over I noticed bubbles coming out the top of the injectors, which would make sense if the injectors are opening at the wrong time when there is compression in the cylinders, as per my post above. It has been a hunch of mine all along that pressure is getting back through the injectors.

 

[Mike.R.B]

Henro - Also I have tried a different injector pump, and I've also (after finding it would not start) dismantled cleaned and checked the injectors which all seem fine. I have had them firing outside of the engine too, with no problems.
In my view you would also be correct in thinking that because it IS firing (although, not running properly) that there is compression. This is why I have ruled this out.

 

[kubotasam]

It seems that the cams for the injector pump are firing in between the ignition and exhaust cycle (between bang and blow). I would think they would fire at the same time that the air intake valve opens on the intake cycle. I'm not sure what's going on.

The injector should provide the fuel into the combustion chamber at the top of the compression stroke. Not on the intake stroke when the valve is open.

 

[SidecarFlip]

My only comment is marks or no marks, it's out of time.

 

[200mph]

JPB7745 said:

Are you sure all pistons went back in the correct cylinder I know the D950 engines #2 piston stroke was just a tad bit longer than the #1 and #2.

sorry #1 and #3

Out of curiosity... Why is the stroke different in #2?

 

[RCW]

I am by no means a diesel mechanic but it sounds to me like there is air in the fuel line.

Joe - - like you, I'm not too slick at this stuff either, but my original question was how this is being fed fuel, especially if it's just on a stand and not in a tractor, etc.

If this IP is supposed to to have 2-3 psi of fuel on it's inlet, could cause what he's talking about. Could be many other problems, but start simple....