12HT no start after injector replacement

[marshcat]

A couple months ago I took the diesel injectors and the turbocharger out of my '87 HJ61 and sent them off for rebuild. I just finished reinstalling today following the steps in the FSM.

I cranked over the engine for almost a minute and the engine doesn't start. Any thoughts what could be wrong? Could the issue be air in my fuel lines? If so, what is the best way to bleed the lines?

thank you!

 

[duncanrm]

Maybe you've disturbed the vacuum pipes around the shutoff butterfly on the intake manifold?

 

[kevin in okinawa]

use the manual pump on the IP to get the air out of the system. You have to crack at least one line and pump that little cylinder pump until fuel comes out of the line(s). ...someone else with more knowledge will chime in but I'm pretty sure that's the course of action for you. check the FSM troubleshooting for "won't start" or something in the fuel section.

 

[marshcat]

use the manual pump on the IP to get the air out of the system. You have to crack at least one line and pump that little cylinder pump until fuel comes out of the line(s). ...someone else with more knowledge will chime in but I'm pretty sure that's the course of action for you. check the FSM troubleshooting for "won't start" or something in the fuel section.

It runs! The manual pump provided no resistance so I'm guessing it's broken. But I cracked a fuel line and cranked the engine until diesel started pouring out. Then tightened the line back up and the engine came back to life. Haven't taken it for a proper shakedown yet but seems to run well!

Anyone recognize these screws btw? I can't figure out where they go. According to my labeled bag they belong towards the back of the heater pipe above the injectors

 

[duncanrm]

Those screws look like they are off older style hose clamps.

 

[marshcat]

Those screws look like they are off older style hose clamps.

Ah yes, you're right! That makes sense now. I replaced all the heater hoses and clamps while I was in there.

That means no leftover parts. Hooray!

 

[marshcat]

Been using the 60 as my daily driver this past week. It's running great!

I'm getting a lot of white smoke on cold start however, and for the first couple minutes of operation. After that the engine seems to run well with no smoke.

Is there an adjustment I can make on the injection pump to reduce startup smoke? I wonder if the pump was adjusted for my old, dirty injectors and so now is misadjusted for my newly rebuilt injectors.

 

[relaxedcruiser]

There should be no white smoke at all. It usually means unburnt diesel.
Have you tested the compression of the cylinders ? Low compression makes diesels start sluggish and with white smoke. But it must not be that bad...
Injection pumps are not adjusted to old or new injectors by the way.
What ambient temperatures are you at when starting ?
Does the engine fire right away basicly within the first or second revolution of the crank ?
Is your butterfly shut off valve open when you are starting it ?
I would also double check the timing of the pump as per FSM.

 

[marshcat]

There should be no white smoke at all. It usually means unburnt diesel.
Have you tested the compression of the cylinders ? Low compression makes diesels start sluggish and with white smoke. But it must not be that bad...
Injection pumps are not adjusted to old or new injectors by the way.
What ambient temperatures are you at when starting ?
Does the engine fire right away basicly within the first or second revolution of the crank ?
Is your butterfly shut off valve open when you are starting it ?
I would also double check the timing of the pump as per FSM.

I haven't tested the compression. For what it's worth I don't see any blow-by when I remove the oil cap.

Ambient temperature right now is ~0 Celcius

Yes, the engine fires immediately. Not sure about the butterfly shut off valve. How would I check that?

 

[relaxedcruiser]

The butterfly shut off valve sits on top of the inlet manifold it should be open when starting - it will be closed by that diaphragm/vacuum next to it when you want to stop the engine. Look at it when somebody switches your engine off - then after the engine has stopped, switch the ignition back on you should see the action of the rods and levers which are operating the valve. I don't think that your problem is located here but it´s good to check it anyway.
At zero degree celsius my engine will turn two revolution before it fires - and that is without any glowscreen action. So your starting sounds absolutely right. These engines are amazing starters.
Do you have the usual black puff when starting ? I mean when the engine is hot and doesn´t develop the white smoke ?
As I said - recheck the timing - that´s not very complicated - the manual describes it. Although I prefer the spill timing method which we used on old diesels when I was in my apprenticeship. Way easier to see the exact point where delivery starts. But that´s annother story.

 

[marshcat]

The butterfly shut off valve sits on top of the inlet manifold it should be open when starting - it will be closed by that diaphragm/vacuum next to it when you want to stop the engine. Look at it when somebody switches your engine off - then after the engine has stopped, switch the ignition back on you should see the action of the rods and levers which are operating the valve. I don't think that your problem is located here but it´s good to check it anyway.
At zero degree celsius my engine will turn two revolution before it fires - and that is without any glowscreen action. So your starting sounds absolutely right. These engines are amazing starters.
Do you have the usual black puff when starting ? I mean when the engine is hot and doesn´t develop the white smoke ?
As I said - recheck the timing - that´s not very complicated - the manual describes it. Although I prefer the spill timing method which we used on old diesels when I was in my apprenticeship. Way easier to see the exact point where delivery starts. But that´s annother story.

Thank you for the info!

Yesterday I parked in the gym garage and was away for 2+ hours. When I came back the truck started right up with zero smoke.

It only belches smoke when it's truly ice cold. I don't think I have the usual black puff, no.

 

[relaxedcruiser]

The 12HT injection pump with stock settings dumps a lot of fuel through the nozzles to facilitate starting as much as possible.
If your starting behavior is not like this I would question the settings. Having said that, I have fitted a device to my pump which limits the amount of diesel pumped at cranking revolutions to a point where the engine starts without smoke - and it will do it at zero °C (without pre heat) without any white smoke.
So that might not be your problem but it is a hint that something is not at spec as it should.
Does the engine fires up on all six simultaneously ? How is the combustion noise, any knocking ?
You said that the injection pump and nozzles have just been checked and adjusted - that's fine ..... but if I run into any problems during my work as a mechanic - I always double check what I have done or worked on beforehand before searching elsewere. So they, god forbid, could be the issue.
I would just make sure that you know that all the standard settings like valve clearances and IP timing are checked and adjusted correctly, measure the compression pressure, that air and fuel filters are perfect, that there are no air or diesel leaks in the system,...etc. So you know that everything is up to spec. And it will soon warm up - and if you have no issues at higher temps.....just enjoy the great engine.

 

[marshcat]

The 12HT injection pump with stock settings dumps a lot of fuel through the nozzles to facilitate starting as much as possible.
If your starting behavior is not like this I would question the settings. Having said that, I have fitted a device to my pump which limits the amount of diesel pumped at cranking revolutions to a point where the engine starts without smoke - and it will do it at zero °C (without pre heat) without any white smoke.
So that might not be your problem but it is a hint that something is not at spec as it should.
Does the engine fires up on all six simultaneously ? How is the combustion noise, any knocking ?
You said that the injection pump and nozzles have just been checked and adjusted - that's fine ..... but if I run into any problems during my work as a mechanic - I always double check what I have done or worked on beforehand before searching elsewere. So they, god forbid, could be the issue.
I would just make sure that you know that all the standard settings like valve clearances and IP timing are checked and adjusted correctly, measure the compression pressure, that air and fuel filters are perfect, that there are no air or diesel leaks in the system,...etc. So you know that everything is up to spec. And it will soon warm up - and if you have no issues at higher temps.....just enjoy the great engine.

I sent a video to the shop that rebuilt my turbo and they think my IP timing is off. How did you make the spill tube to check the timing? Any tips for loosening the IP to make the timing adjustment?

 

[Knowbuddy]

Spill timing is pretty simple. it's the angle of the injection pump orientation. I did it without a spill tube after my full rebuild.

 

[marshcat]

Update-

I ended up bringing my 60 to a diesel specialist out in Western Mass. They mostly work on Cummins and Powerstroke, but were willing to take a look at my 12HT.

Spill timing was about 1 degree off, not enough to cause the smoke. Next up they quoted 3 - 4 hours labor to replace the valve stem seals. If that doesn't do the trick we'll be talking about piston rings.

 

[FJBen]

Update-

I ended up bringing my 60 to a diesel specialist out in Western Mass. They mostly work on Cummins and Powerstroke, but were willing to take a look at my 12HT.

Spill timing was about 1 degree off, not enough to cause the smoke. Next up they quoted 3 - 4 hours labor to replace the valve stem seals. If that doesn't do the trick we'll be talking about piston rings.

I had the same issue after a full rebuild on my 13bt. I advanced the timing a little and it all pretty much went away. So you might be able to advance the timing a little more, rotate the pump and I bet it clears mostly up.

Did the white smoke only occur after injectors?

 

[marshcat]

The diesel shop pulled the head and sent it to a machine shop for a full valve job.

Not a cheap repair but I've been daily driving the 60 for the past few weeks and it's so much nicer not having all the startup smoke.

Previously I had several minutes of moderate smoke at cold start. Now, after the valve job, I have 10 seconds of light smoke at cold start after which it runs totally clean.