1HD-FT loud injection pump, goes quiet when pumping the hand primer

[JWEN]

Hey all, looking for some input on a noisy pump. I've read through a bunch of threads (linked below) and a few are close, but none quite match and none of them seem to have been resolved.
Truck's been recently imported from Japan, I don't have history on anything. I do not recall it making this noise when I picked it up from the port with Japanese diesel still in the tank, but honestly I can't recall if it started after a fresh fill up.

Truck:
- 1997 JDM HDJ81, 1HD-FT, auto, with EGR and BACS (180,000KM~)
- Pump looks like it was replaced at some point? clean body, fresh tags, paint marks on the fasteners metal looks less oxidized than others around (will add picture of pump when I am home)

What it's doing:
- Injection pump is loud, a clattery noise at idle and through the revs
- Fires up within a second, idles smooth, no hunting, no hard starting, no stalling
- Maybe a bit down on power? but I don't have a baseline for this truck honestly to tell if it is or isn't

What I've noticed:
- Pumping the hand primer while it's running makes the noise go away completely
- Before I deleted the ACSD, rotating its lever counterclockwise by hand also made it go quiet
- Before the delete it was only loud warm. Now it's loud cold and warm

What I've done/ruled out:
- ACSD deleted, block-off plate and new O-ring, shaft tip was intact
- New fuel filter
- Clear line from filter outlet to pump inlet: no air at idle or revving
- Ran it with the fuel cap off: no change
- No noticeable blow-by
- Static timing hasn't been checked since the delete or since importing (not sure if I even need to have the static timing verified running on North American diesel? Not something I've really seen too many threads on)

My thinking is low or unstable case pressure? since both the primer and the ACSD lever act on the timer piston one way or another. So it's either the regulating valve, the overflow screw, or the feed pump getting tired? I'm no diesel mechanic or IP expert so I'm shooting in the dark here hoping the pump doesn't need to be rebuilt

Has anyone had this exact combo and found out which it was? I don't want to pull the pump out and have it rebuilt if it's not necessary to do that, it seems like a healthy pump to me otherwise

Threads I've already read:
- Noisy Injector Pump: Noisy Injector Pump - https://forum.ih8mud.com/threads/noisy-injector-pump.828690/
- Lost pressure in priming pump: lost pressure in priming pump - https://forum.ih8mud.com/threads/lost-pressure-in-priming-pump.237225/
- 1HDFT rattling noise timing gear / injection pump: 1HDFT rattling noise timing gear / injection pump - https://forum.ih8mud.com/threads/1hdft-rattling-noise-timing-gear-injection-pump.1196499/
- Another Walbro thread: Another Walbro Thread - Successful Cure of a Stumbling 1HDFT - https://forum.ih8mud.com/threads/another-walbro-thread-successful-cure-of-a-stumbling-1hdft.290354/

I'll add a video of the sound and a picture of the pump when I get home.

Thanks in advance.

 

[JWEN]

Cannot seem to edit the original post..

Pump Sound

 

[JWEN]

For anyone else looking for a solve to this problem, this is the answer that worked for me.

 

[TheBussman]

would like to know, it's blank for me.

For anyone else looking for a solve to this problem, this is the answer that worked for me.

 

[gilmorneau]

The video is on Facebook here:


Be prepared for a very Australian Australian. I had to watch it a couple times to pick up all that he was putting down. lol

His (primary) theory is that the noise you hear is coming from the timing piston in the pump. Normally, one side of the piston is exposed to the pump's internal pressure. The opposite side of the piston houses a spring that pushes back against the hydraulic pressure. When everything's working right, the piston can't "rattle" because it's "squeezed" between these two opposing forces.

The noise (in the video, he calls it "FT Hammer") can be because of low case pressure, a weak spring, or a worn case.

Possible causes of low case pressure are:

Fuel restriction (dirty fuel filter, blocked p/u in fuel tank, partially blocked intake screen in pump) can be anywhere the flow of fuel is restricted. This can cause low pressure and cavitation in the pump.

Air ingress (common culprits are the primer pump diaphragm, the o-ring at the bottom of the fuel filter, loose or aged hose connections, etc.) can be anywhere air can get into the line.

Pump pressure regulator valve worn or malfunctioning.

Overflow return restrictor orifice eroded (probably only possible on very high mileage motors)

A weak spring
can just be from fatigue. It can be shimmed or replaced.

Worn case bore
can "leak" pressure. The piston and bore in the video are badly worn from abuse and/or neglect (..."look at the wweeeeeaaaarr, mate!) Some shops talk of boring and sleeving, but the best fix is probably a new case.

What am I forgetting?

BTW, when guys "fix" the problem with a lift pump, they're just increasing case pressure at idle by a couple of psi, which is enough to push the timing piston against the spring, which is where it belongs. This is what happens when you push the primer pump a few times. In the video, he suggests that another fix is to shim the spring, which has the same effect but from the other side. That is, it increases preload on the spring enough to push it against the piston. In the video, he measures the old spring and determines it's lost about 1mm of its original length, presumably due to fatigue.

I found it an interesting video, and his hypotheses seem for the most part valid to me. If it was me trying to solve this problem, I'd start with the easiest things (fuel restrictions, air in the line). The very last stop on the journey would be pulling the pump out to get it rebuilt.

OP @JWEN when you say the video solved your problem, which of the things he mentioned did you implement as a solution?

 

[JWEN]

would like to know, it's blank for me.

Let me try to embed the link, I think my new account has less privileges

Video

 

[JWEN]

The video is on Facebook here:


Be prepared for a very Australian Australian. I had to watch it a couple times to pick up all that he was putting down. lol

His (primary) theory is that the noise you hear is coming from the timing piston in the pump. Normally, one side of the piston is exposed to the pump's internal pressure. The opposite side of the piston houses a spring that pushes back against the hydraulic pressure. When everything's working right, the piston can't "rattle" because it's "squeezed" between these two opposing forces.

The noise (in the video, he calls it "FT Hammer") can be because of low case pressure, a weak spring, or a worn case.

Possible causes of low case pressure are:

Fuel restriction (dirty fuel filter, blocked p/u in fuel tank, partially blocked intake screen in pump) can be anywhere the flow of fuel is restricted. This can cause low pressure and cavitation in the pump.

Air ingress (common culprits are the primer pump diaphragm, the o-ring at the bottom of the fuel filter, loose or aged hose connections, etc.) can be anywhere air can get into the line.

Pump pressure regulator valve worn or malfunctioning.

Overflow return restrictor orifice eroded (probably only possible on very high mileage motors)

A weak spring
can just be from fatigue. It can be shimmed or replaced.

Worn case bore
can "leak" pressure. The piston and bore in the video are badly worn from abuse and/or neglect (..."look at the wweeeeeaaaarr, mate!) Some shops talk of boring and sleeving, but the best fix is probably a new case.

What am I forgetting?

BTW, when guys "fix" the problem with a lift pump, they're just increasing case pressure at idle by a couple of psi, which is enough to push the timing piston against the spring, which is where it belongs. This is what happens when you push the primer pump a few times. In the video, he suggests that another fix is to shim the spring, which has the same effect but from the other side. That is, it increases preload on the spring enough to push it against the piston. In the video, he measures the old spring and determines it's lost about 1mm of its original length, presumably due to fatigue.

I found it an interesting video, and his hypotheses seem for the most part valid to me. If it was me trying to solve this problem, I'd start with the easiest things (fuel restrictions, air in the line). The very last stop on the journey would be pulling the pump out to get it rebuilt.

OP @JWEN when you say the video solved your problem, which of the things he mentioned did you implement as a solution?

I just went straight for the lift pump, I’ve come to the conclusion that it’s highly likely the pump and injectors just need to be sent in. Being that is a costly job, as a temporary solution this works in the meantime.
I didn’t have the specs for the shim, and did not want to use anything other than a DIM 988 or equivalent shim, and where I live finding that would have been a little difficult on short notice. Though I think that it’s highly likely that would have solved my problem as well.

Next year I’ll pull the pump and the injectors and have them sent in to be rebuilt; and pull the temporary lift pump off.

 

[TheBussman]

The video is on Facebook here:


Be prepared for a very Australian Australian. I had to watch it a couple times to pick up all that he was putting down. lol

His (primary) theory is that the noise you hear is coming from the timing piston in the pump. Normally, one side of the piston is exposed to the pump's internal pressure. The opposite side of the piston houses a spring that pushes back against the hydraulic pressure. When everything's working right, the piston can't "rattle" because it's "squeezed" between these two opposing forces.

The noise (in the video, he calls it "FT Hammer") can be because of low case pressure, a weak spring, or a worn case.

Possible causes of low case pressure are:

Fuel restriction (dirty fuel filter, blocked p/u in fuel tank, partially blocked intake screen in pump) can be anywhere the flow of fuel is restricted. This can cause low pressure and cavitation in the pump.

Air ingress (common culprits are the primer pump diaphragm, the o-ring at the bottom of the fuel filter, loose or aged hose connections, etc.) can be anywhere air can get into the line.

Pump pressure regulator valve worn or malfunctioning.

Overflow return restrictor orifice eroded (probably only possible on very high mileage motors)

A weak spring
can just be from fatigue. It can be shimmed or replaced.

Worn case bore
can "leak" pressure. The piston and bore in the video are badly worn from abuse and/or neglect (..."look at the wweeeeeaaaarr, mate!) Some shops talk of boring and sleeving, but the best fix is probably a new case.

What am I forgetting?

BTW, when guys "fix" the problem with a lift pump, they're just increasing case pressure at idle by a couple of psi, which is enough to push the timing piston against the spring, which is where it belongs. This is what happens when you push the primer pump a few times. In the video, he suggests that another fix is to shim the spring, which has the same effect but from the other side. That is, it increases preload on the spring enough to push it against the piston. In the video, he measures the old spring and determines it's lost about 1mm of its original length, presumably due to fatigue.

I found it an interesting video, and his hypotheses seem for the most part valid to me. If it was me trying to solve this problem, I'd start with the easiest things (fuel restrictions, air in the line). The very last stop on the journey would be pulling the pump out to get it rebuilt.

OP @JWEN when you say the video solved your problem, which of the things he mentioned did you implement as a solution?

thanks!

 

[SNLC]

I have put brand new springs in the pump that were difficult to source. It made no difference.

Cheers