1HDT HDJ81 Misfire

Joined
Jan 10, 2017
Messages
1,524
Location
New England, USA
To tune these you need to make use of boost gauge, and either an EGT gauge, or an AFR gauge.
If they aren't using gauges, they are really fxcking with what they don't understand.

Yes, you can tune by the seat of the pants, but they either be leaving potential power on the table, or compromising economy for power, and putting engine and turbo at risk from high EGTs.

There's a fine line between tuning for power and running too hot.
This needs to be tested with the engine under load. The only way to test is with gauges, or dyno and gauges.

Same with timing the pump. You can take a stab at it with trial and error, but without starting from a factory baseline, they are flying blind.


Honestly, if I had a customer's rig for 6 months without an awesome result, I'd quit my job and go and pack supermarket shelves for a living or get a job licking windows.

Sorry to be harsh, but that's just embarassing.

As usual, I agree with you. The only thing I'd add is that tuning these things is really easy. The diesel crowd here helped me get mine tuned easily.

@ubguessin Get compression numbers first.
Then get your gauges in and the guys here can help you get tuned. A quick video showing the issue might help too.
 
Joined
Sep 16, 2019
Messages
58
Location
Montana
As usual, I agree with you. The only thing I'd add is that tuning these things is really easy. The diesel crowd here helped me get mine tuned easily.

@ubguessin Get compression numbers first.
Then get your gauges in and the guys here can help you get tuned. A quick video showing the issue might help too.
Just got done at the shop, I have plenty of confidence after this interaction with them to continue moving forward with them.

Compression on each cylinder ranged from 453psi-to 475psi

Here is a link of the running condition
 
Joined
Dec 17, 2007
Messages
4,281
Location
Sydney, Australia
 
 
Idle sounds perfect! 👍


If fuel lines and fuel filter are clear, I'd say after looking at that there's a problem inside the pump.

Possibly something is astray with the governor arm linkages inside the pump. It's linked to the throttle arm on the outside with a series of springs and levers inside. If a spring is loose or incorrect it could be the problem.

If it's a problem in the pump and they haven't opened the pump, they would have seen similar throttle response even if previous injectors weren't perfect.
Even if a couple of injectors were totally bad previously, it would have still jumped to attention with that amount of throttle input, albeit with a possible misfire.

Regardless of turbo or injectors, turning the throttle like that you should see an immediate increase in RPM
 
Joined
Jul 22, 2003
Messages
17,604
Location
Perth Western Australia
 
 
 
Just got done at the shop, I have plenty of confidence after this interaction with them to continue moving forward with them.
I hope these people are not going to open your pump up. If Im reading it right and they took 6 months to get this far, then they are in one word, incompetant. You could have packed that injection pump into a box, sent it to an expert and had it back in a week or 2.
 
Joined
Sep 16, 2019
Messages
58
Location
Montana
I hope these people are not going to open your pump up. If Im reading it right and they took 6 months to get this far, then they are in one word, incompetant. You could have packed that injection pump into a box, sent it to an expert and had it back in a week or 2.
This pump was sent to some experts in BC and they are diligently working with the shop my cruiser is at to make the issues right. It damn well sucks for all parties involved no doubt. There has been many variables that have gotten to this point and I have already slung mud in my frustration of not understanding what is going on. After today I have more confidence in their diligence of making this right, and a better understanding of what is going on.
 
Joined
Sep 16, 2019
Messages
58
Location
Montana
Idle sounds perfect! 👍


If fuel lines and fuel filter are clear, I'd say after looking at that there's a problem inside the pump.

Possibly something is astray with the governor arm linkages inside the pump. It's linked to the throttle arm on the outside with a series of springs and levers inside. If a spring is loose or incorrect it could be the problem.

If it's a problem in the pump and they haven't opened the pump, they would have seen similar throttle response even if previous injectors weren't perfect.
Even if a couple of injectors were totally bad previously, it would have still jumped to attention with that amount of throttle input, albeit with a possible misfire.

Regardless of turbo or injectors, turning the throttle like that you should see an immediate increase in RPM
The idle sounds good but the motor shakes more then usual and it is definetly smoking a buck ton at idle.
 
Joined
Jul 22, 2003
Messages
17,604
Location
Perth Western Australia
 
 
 
After today I have more confidence in their diligence of making this right, and a better understanding of what is going on.

I hope your right but they should have had a good understanding before you arrived on the scene. Their website is woefully thin on actual diesel knowledge. Stay in touch with the MUD diesel forum.
 
Joined
Sep 16, 2019
Messages
58
Location
Montana
I hope your right but they should have had a good understanding before you arrived on the scene. Their website is woefully thin on actual diesel knowledge. Stay in touch with the MUD diesel forum.
They had called me right as I pulled up to the shop to tell me what was going on.
Idle sounds perfect! 👍


If fuel lines and fuel filter are clear, I'd say after looking at that there's a problem inside the pump.

Possibly something is astray with the governor arm linkages inside the pump. It's linked to the throttle arm on the outside with a series of springs and levers inside. If a spring is loose or incorrect it could be the problem.

If it's a problem in the pump and they haven't opened the pump, they would have seen similar throttle response even if previous injectors weren't perfect.
Even if a couple of injectors were totally bad previously, it would have still jumped to attention with that amount of throttle input, albeit with a possible misfire.

Regardless of turbo or injectors, turning the throttle like that you should see an immediate increase in RPM
What I was told was that before the other 4 new injectors were installed the throttle had better response, now its basically non existent. Fuel filter was replaced during their diagnostics and leakage pipe was tested for flow to make sure there were no blockages.

And before the pump was rebuilt their were no known issues causing problems. They completely bypassed the fuel tank to make sure it was not a suction issue in the tank and still the same symptoms persist. Clear hose has been used to check for air in the lines as well and the fuel primer pump is good to go as well.
 
Joined
Mar 28, 2002
Messages
4,659
 
 
 
 
@ubguessin any updates on this?

Not that this should affect your symptoms, as a 1993 1HD-T it should have the 3.5mm washers under the injectors. You can confirm this by checking the IP number and other indicators as the change occurred 08/92. Do you know if the shop that's doing your work reused what came out or put new ones in when they got the stuff back?

gb
 
Joined
Sep 16, 2019
Messages
58
Location
Montana
@ubguessin any updates on this?

Not that this should affect your symptoms, as a 1993 1HD-T it should have the 3.5mm washers under the injectors. You can confirm this by checking the IP number and other indicators as the change occurred 08/92. Do you know if the shop that's doing your work reused what came out or put new ones in when they got the stuff back?

gb
Well the cruiser is still sitting outside of the shop collecting sunshine. I was told that apparently the wooddruff key for the injection pump was the wrong size or some BS like that. I was told that this has caused the pump to shift out of timing. So the shop ordered a new kit to replace those parts. I was told that those parts would be here by the 12th of April. Well were at the 20th and I still have not got a phone call on any updates.
 
Joined
Sep 16, 2019
Messages
58
Location
Montana
Alright well I finally got the Ol s***box back in my possesion, I am not impressed.

It now Smokes WAY WORSE then when I took it in. It is a constant stream of greyish smoke at idle as well as Greyish/black accelerating. The engine has an "Idle Lope" and the acceleration it had before I took it in is gone. I give it half throttle and the f***er moves like a turtle for 5 seconds before any power kicks in, as well there is an odd Exhaust "slapping" noise under acceleration . I was told the AFR is right in the sweet spot 22.1AFR.

What can I do to get this thing running right?
 
Joined
Jul 22, 2003
Messages
17,604
Location
Perth Western Australia
 
 
 
Has the turbo been inspected?

Black smoke is over fueling. It can be from bad injectors , fuel settings incorrect or air blockage.
I would be leaning to fuel settings.

The grey smoke I don't know, its usually associated with poor compression, or is combustion that is too cool.

Where is the slapping noise coming from?

And the only advice I can offer is to look for someone else which is not easy at the moment.
 
Joined
Sep 16, 2019
Messages
58
Location
Montana
Has the turbo been inspected?

Black smoke is over fueling. It can be from bad injectors , fuel settings incorrect or air blockage.
I would be leaning to fuel settings.

The grey smoke I don't know, its usually associated with poor compression, or is combustion that is too cool.

Where is the slapping noise coming from?

And the only advice I can offer is to look for someone else which is not easy at the moment.
The "slapping" or popping noise similar to a back fire is coming from the exhaust under acceleration I dont have any other way of explaining it. You can slightly hear it in the video I posted. The Turbo has not been inspected.
 
Joined
Sep 16, 2019
Messages
58
Location
Montana
I could hear something like a slapping noise. Maybe an exhaust leak. Were the valves checked?

Whats the mechanic saying now?
I am waiting for the SStool so I can do the valves.

The mechanic acted like it had plenty of power and not much issues besides the smoking. He believed a valve adjustment needed to be done. Valve seals possibly.

He references the delay in accelerating but acted like it was hardly an issue. It is snail pace of accelerating you give it 1/2 to 3/4 throttle and have to wait 5 seconds for anything to happen, it was never like this before I brought it in.
 
Top Bottom