Jake_IN
Full Access Member
That makes me feel a bit better. So maybe for starters i'll try and get some more run time on it keeping the RPM's moving around to keep that noise at bay, and we'll see if it clears up.
Bad sound on a fresh rebuild (video)
- Thread starter Jake_IN
- Start date
TNBrett
Full Access Member
Do you have the belts on it? I swear I’ve heard a vac pump sound exactly like that before. I know it’s a long shot, I’m hoping it’s something simple for you.
Jake_IN
Full Access Member
Ok here is another short update.
Been taking the truck on some short runs, probably have about 30 or 40 miles on it. If i keep it below 2000 rpms you wouldn't know anything was wrong with it. Something else i noticed is that when i just mash it and try and scoot, after that 2k mark when it starts acting up. It just falls on its face. I guess in my head i would think if a single cylinder was acting up it would be able to "power through" that with the other 7.
I also installed a fuel pressure gauge and once warmed up i see about 3psi of fuel (at the schrader valve) at all times.
Since the first video, i retarded the timing a fuzz because i felt like when the idle advance was on the engine was just sounding to advanced. It would also have a constant very light haze of black smoke at idle when the advance was engaged. So i brought it back a little. Still flying blind though because i can't get the Gunson timing adapter to cooperate with me. With the old timing setting when the engine would "act up" the smoke was much more gray/black than what you see in this video, and in my opinion there wasn't as much either.
You can see at around the 23 second mark it actually starts to run right for a couple seconds, then you can hear it sound like it bogs down a bit and the smoke show starts.
Been taking the truck on some short runs, probably have about 30 or 40 miles on it. If i keep it below 2000 rpms you wouldn't know anything was wrong with it. Something else i noticed is that when i just mash it and try and scoot, after that 2k mark when it starts acting up. It just falls on its face. I guess in my head i would think if a single cylinder was acting up it would be able to "power through" that with the other 7.
I also installed a fuel pressure gauge and once warmed up i see about 3psi of fuel (at the schrader valve) at all times.
Since the first video, i retarded the timing a fuzz because i felt like when the idle advance was on the engine was just sounding to advanced. It would also have a constant very light haze of black smoke at idle when the advance was engaged. So i brought it back a little. Still flying blind though because i can't get the Gunson timing adapter to cooperate with me. With the old timing setting when the engine would "act up" the smoke was much more gray/black than what you see in this video, and in my opinion there wasn't as much either.
You can see at around the 23 second mark it actually starts to run right for a couple seconds, then you can hear it sound like it bogs down a bit and the smoke show starts.
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Jake_IN
Full Access Member
The RPMs will continue to climb a little if i'm just reving it like in the video. If i'm going down the road i don't really try and push it because more throttle just means more smoke and no real increase in speed or power. Kind of like it goes from bogging, to just bogging harder.
Pump and injectors are from @typ4
Booyah45828
Full Access Member
What's the smoke smell like? That's a lot of smoke to have on a fresh build, or is it just condensation and cold?
You're thinking right though, that if it was a single cylinder issue, you'd have a misfire instead of a bog. I'm thinking you need to tackle the timing, verify fuel pressure while under load, and ensure there isn't any air in the fuel supply system.
If you do all of that and come up with nothing, do you have a spare injection pump you could throw on and try? That'd be my next step.
You're thinking right though, that if it was a single cylinder issue, you'd have a misfire instead of a bog. I'm thinking you need to tackle the timing, verify fuel pressure while under load, and ensure there isn't any air in the fuel supply system.
If you do all of that and come up with nothing, do you have a spare injection pump you could throw on and try? That'd be my next step.
Is there a chance that you are 180 out?
Black dawg
Registered User
I have heard engines make noise back through the intake like that when the exhaust was restricted.....your description of power while driving it makes me wonder.
Jake_IN
Full Access Member
Haven't thought about smelling the smoke. So i can't answer that. It was about 35 degrees (1.6 C) out when i took that video though.
Don't have a spare pump on hand.
Well as usual, despite taking a million pictures during this rebuild, i don't have a clear one of the pump gear meshed with the cam. I have a clear one of the crank and the cam, but not the pump gear. So being 180 out can't be ruled out. Do you know if the pump gear can come un-meshed from the cam gear even with the housing on? I know after i installed the housing that the engine did get flipped upside down on the stand at least 2 or 3 times.
Certainly a possibility, This is the same exact exhaust that was on there prior to rebuild and the engine didn't have any issues with it.
Booyah45828
Full Access Member
If it's 180 out, it would be low on power and have a near constant haze out of the exhaust. But I don't think it would ever "clear up" for a second like it did in your video.
Might be worth checking and trying though.
Might also explain the "Chuff" out the intake you were hearing too, as the injector firing would be happening at overlap, which is at/during the intake valve opening.
Might be worth checking and trying though.
Might also explain the "Chuff" out the intake you were hearing too, as the injector firing would be happening at overlap, which is at/during the intake valve opening.
How are the case/pump reference marks relating where you've blind timed it?
yeah, the pump gear just floats there unattached. So inverting could take it out. Some do manage to confirm/reposition gear aligmnet with case in place btw
yeah, the pump gear just floats there unattached. So inverting could take it out. Some do manage to confirm/reposition gear aligmnet with case in place btw
Jake_IN
Full Access Member
Pump is advanced from the ref. mark by just about the width of the mark. So not much, but advanced some.
Ofcourse that mark is just for getting in the initial ball park. May be injection timing is late. Either because of static being out or just not advanced enough. The mild mannered sound and snap to idle make me think late injection.
Don't let me muddle your thinking, but something similar occurred when I replaced my pump with a recently rebuilt salvage yard unit. At 2k the truck would fall flat and to get going any more it was a matter of mashing the peddle. Swapped the old pump back in and it was cured. I still don't know what it was. My mind leans towards governor/accellerator linkage business or advance piston bore leak-off.
Don't let me muddle your thinking, but something similar occurred when I replaced my pump with a recently rebuilt salvage yard unit. At 2k the truck would fall flat and to get going any more it was a matter of mashing the peddle. Swapped the old pump back in and it was cured. I still don't know what it was. My mind leans towards governor/accellerator linkage business or advance piston bore leak-off.
With IP removed and gear cover in place, the gear can rock side to side but there isn't enough clearance for it to jump a tooth. If rotating the engine inverted the gear can hang up on the block edge and stop rotation. I used an old IP to keep the gear in place to prevent this.
hacked89
Full Access Member
In theory, if you are blowing white smoke at 2k rpm and up wouldn’t that mean that the engine is not able to combust the diésel appropriately/efficiently/enough to meet the fuel that’s entering the chamber? IE not enough air, air not getting in or out of the heads appropriately, compression, too much fuel from IP for air capacity, too large of injector etc
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