1HDT HDJ81 Misfire (1 Viewer)

[mudgudgeon]

Hey guys, first post for me here. Found the thread as I’ve got very similar issues with my 1hdt also. Have rebuilt pump, injectors, bottom end rebuild even though compression was good. Chasing bad white smoke at idle and cold start also! None of the work I’ve carried out had made a difference to the smoke. My injector lines are over flared and possibly causing a air leak as no there is no evidence of air before the pump. Will be following this thread and posting if I do end up finding the issue! Cheers,

If your injector lines were leaking, you'd see diesel seeping around the nuts.
Injector lines won't be bringing air in to the fuel system as the fuel in the lines is under extremely high pressure.

Fuel lines from the tank to the pump are under a partial vacuum which is why it's possible to have a leak that sucks in air, but doesn't leak fuel

 

[Lumpskie]

If your injector lines were leaking, you'd see diesel seeping around the nuts.
Injector lines won't be bringing air in to the fuel system as the fuel in the lines is under extremely high pressure.

Fuel lines from the tank to the pump are under a partial vacuum which is why it's possible to have a leak that sucks in air, but doesn't leak fuel

I just chased down an instance of that on my rig. I had a leak on a fitting to my lift pump. My rig always seemed a little stinky. I recently found a couple of local buddies that now have 1HDT rigs and I realized that my rig was indeed stinkier and slightly smokier than theirs at idle. When the fittings were changed, all of that changed. I might get a touch of odor at cold idle now. But, once warm, there is not smoke and no smell. A little air must have been getting into the system from those fuel lines at the lift pump.

 

[ubguessin]

I just chased down an instance of that on my rig. I had a leak on a fitting to my lift pump. My rig always seemed a little stinky. I recently found a couple of local buddies that now have 1HDT rigs and I realized that my rig was indeed stinkier and slightly smokier than theirs at idle. When the fittings were changed, all of that changed. I might get a touch of odor at cold idle now. But, once warm, there is not smoke and no smell. A little air must have been getting into the system from those fuel lines at the lift pump.

Any connections for getting new lines?

 

[Lumpskie]

Any connections for getting new lines?

Fuel lines? If I was in Montana, I'd give Back40 Imports ( @mudandrock )a call. I bought an alternator from him and he was really helpful in troubleshooting. He repetively took time out of his day to answer questions before I ordered with him. He has a lot of stuff on hand (Including a couple rigs he is parting out) and knows where to get almost anything. Not sure how far he is from you... but at least he's in the same state.

 

[roscoFJ73]

Any connections for getting new lines?

Are we talking about injector lines or the rubber fuel lines from filter to injection pump?

 

[ubguessin]

Are we talking about injector lines or the rubber fuel lines from filter to injection pump?

I was talking injector lines, I remember coming across an article that these lines could only be torqued so many times and then needing replaced.

 

[roscoFJ73]

I had a leak on a fitting to my lift pump

I was confused because Lumpskie seems to be talking about fuel lines

 

[roscoFJ73]

PartSouq have the injector lines for about $31 each, but Im not convinced you need them. Your cyl head would have diesel everywhere if it was bad enough to cause ignition problems

 

[ubguessin]

Just got the injectors out and #5 was coated in soot/fuel and was told it is a dead injector.
I gave them the 4 other rebuilt injectors hopefully something good happens

 

[roscoFJ73]

Its progress

 

[ubguessin]

Apparently the #5 injector is sitting higher then all of the others. Possibly thinking this is a copper washer issue? Or something else?

Might be pulling the head off.

 

[IanB]

Apparently the #5 injector is sitting higher then all of the others. Possibly thinking this is a copper washer issue? Or something else?

Might be pulling the head off.

Is it possible an old washer is still in the hole

 

[roscoFJ73]

Might be pulling the head off

Why would you want to do this? The injector is either wrong or its sitting proud because of a washer. You have good compression, I doubt you will find anything there.

 

[ubguessin]

Why would you want to do this? The injector is either wrong or its sitting proud because of a washer. You have good compression, I doubt you will find anything there.

Would want to do this because the #5 injector is not seating properly

 

[IanB]

Would want to do this because the #5 injector is not seating properly, there is not another washer in the hole.

You're thinking there's an issue with the injector bore in the head?

 

[roscoFJ73]

Would want to do this because the #5 injector is not seating properly, there is not another washer in the hole.

Im sure you would be able to see the problem without removing the head. At worst a cheap boroscope attachment for your phone would do it.
Take another injector out and see if it screws in all the way. Check the injector against another for similarity.

Pulling the head is a big job, I wouldnt be doing it unless its critical.

 

[mudgudgeon]

Im sure you would be able to see the problem without removing the head. At worst a cheap boroscope attachment for your phone would do it.
Take another injector out and see if it screws in all the way. Check the injector against another for similarity.

Pulling the head is a big job, I wouldnt be doing it unless its critical.

I agree.

Do some more investigation before you pull the head.

From what you have described, pulling the head doesn't seem to make sense.

I also agree, I'd be buying a borescope and have a look inside before pulling the head

 

[ubguessin]

I agree.

Do some more investigation before you pull the head.

From what you have described, pulling the head doesn't seem to make sense.

I also agree, I'd be buying a borescope and have a look inside before pulling the head

So far their seems to not be a direct cause as to why the injector is not seating deep enough. The injectors have been compared against each other all matching depth. Other injectors have been inserted and still sit higher then the rest. The mechanic has not found an obstruction to make the injector sit higher.

Does anyone have a connection that could get me a rebuilt head for this motor?

 

[IanB]

Man that's weird. I'll be watching for the outcome of this.

Good luck!

 

[Greg_B]

Very weird. Sure there is not a washer stuck down there that's held in there by soot and whatnot and visually looks like the bottom of the hole?

I made this SST a number of years back for difficult shims (edit - washers).

hth's

gb