Advice needed no top end power (1 Viewer)

[Oregon trail]

hi I need some help with my 96 hdj81 with a 1hd-ft . The last 2 days I’ve drove a lot. From home 3 hours away and back and today a total of 8 hours there and back home. Yesterday a hour into the trip I noticed I was down on power and by the end of the first leg I was down on power it would stutter slightly at full throttle or climbing mountains and there was a loud tick that sounded like the injection pump. The pump is new by the way as fo last august. I figured I hadn’t done a fule filter and it seamed like it was starved of fuel so I grabbed one from a land cruiser shop I know was in the town I was heading to. It seamed to have help and infact I thought it may be fixed. This morning I left home and the tic was still there and I couldn’t find anything rattling. About 30 minutes into the trip I start into the mountains and notice less power a tic and it’s still has a stutter. So from some searching and friends advice it seamed obvious I was getting air in the fuel so when I got to where I was going I did my work and swapped the last old fuel like . From the filter to the pump. This actually made a difference! I definitely had air in the fuel the low end is so much more responsive but the top end still had no power and EGTs are a few hundred degrees lower than usual when on boost and Normal without boost. The last couple hours is all mountains and it was getting worse and ultimately I climbed the same mountains I did this morning but instead of being about to maintain 70 I was crawling as 50 and lower.

Couple things to note. Like I said EGTs are lower. Now if it’s shifted down and high in the revs it has no power won’t accelerate and actually will slow down compared to letting the low end work it’ll maintain 50. There’s now smoke I can see when it sputters but on start up cold or hot there’s a good bit. ADS did the pump and I have a gturbo bad boy turbo. Injectors have never been done. I also just checked the fuel pickup and it’s clean and not clogged.

I’ll attach a video of how it sounds struggling shifted down trying to accelerate so you can hear the stutters now

 

[Oregon trail]

 

[mudgudgeon]

Terrible video!.

Double, triple check you aren't getting air into the pump.
A $10, 3' piece of clear hose from the filter housing to the pump will let you check and be 100% sure it's not air causing you problems.
Air is going to be a problem most likely at full load, or when accelerating.

An increase in altitude means you'll be down on power too, but that should be consistent at the same alttitude

Have you changed anything else recently?

Have you got a boost leak somewhere?

Is the tick definitely from the pump? Not an exhaust manifold leak, or boost leak?

Use a piece of hard tube, long screwdriver, pry bar etc as a stethoscope to pinpoint the noise. Grip one end in your first, press your ear to your first, out the other end of the bar on different parts of the engine to isolate the source of the noise. The closer you are to the source, the more pronounced the noise will be.

Press your ear flat against your fist for HIFI Stereo, well, mono actually, but it works!

 

[Oregon trail]

Terrible video!.

Double, triple check you aren't getting air into the pump.
A $10, 3' piece of clear hose from the filter housing to the pump will let you check and be 100% sure it's not air causing you problems.
Air is going to be a problem most likely at full load, or when accelerating.

An increase in altitude means you'll be down on power too, but that should be consistent at the same alttitude

Have you changed anything else recently?

Have you got a boost leak somewhere?

Is the tick definitely from the pump? Not an exhaust manifold leak, or boost leak?

Use a piece of hard tube, long screwdriver, pry bar etc as a stethoscope to pinpoint the noise. Grip one end in your first, press your ear to your first, out the other end of the bar on different parts of the engine to isolate the source of the noise. The closer you are to the source, the more pronounced the noise will be.

View attachment 3231507

Press your ear flat against your fist for HIFI Stereo, well, mono actually, but it works!

I believe I have clear hose here I’ll throw in tomorrow and see. The noise is gone that’s what’s odd. I changed out the fuel line and like magic it was just gone. I can’t be certain what it was since i couldn’t hear it when I had the hood open and was checking things out.

Definitely am use to power loss at elevation but I drive these mountains often and like I said drove it this morning and on the way back it was very different.

When it did have a tick it was definitely from the left side. And all the exhaust is on the right. I wondered about valves but valves don’t seam to magically go away on there own or changing loads. At idle I never heard it.

I also haven’t changed anything besides engine wise.. I did do a 3 link and a rear 4 link but that’s unlikely to affect a thing

 

[Oregon trail]

I realize I also didn’t answer about a boost leak. I don’t believe it is although it’s worth looking into. And maybe I’m wrong but if I had a boost leak wouldn’t that raise my EGTs not lower them? Less air with same fuel should mean high temps and low power or am I mistaken thinking that? I also take my boost reading from the manifold adapter for the IC so I theoretically should be able to see a boost leak on the gage I would think?