1HZ Injector Clatter?

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athensrep

athensrep

10 Year
Joined
Mar 5, 2014
Threads
58
Messages
425
Location
Easley, SC
1991 1HZ auto with around 150k miles (not KMs). Rebuilt the top end, no smoke, runs great, etc. I searched but can’t find a definitive answer here. When driving around town, it does great with no smoking at all or power loss (for an auto). If I downshift to 2nd for instance, under load and get RPMs up around 2500-3k, I get an awful amount of clatter/non-rythmic nailing sounds. As soon as I let off the accelerator, naturally it ceases immediately. I can’t duplicate this in any other situation except low gears/higher RPMs under load.

It does sound to be coming from the port side of the truck which leads me to the injectors. I don’t have any history of a rebuild, but I’m not losing power, getting good economy, etc. Could this be a lack of fuel issue? I can’t find any leaks in the system although I did have to replace an o-ring at the fuel filter housing at one point. Valves?

Has anyone experienced this or has more diesel knowledge on this kind of occurrence? Thanks in advance.
 
None from the manifold. The muffler is another thing.
 
150k is a good run for a set of injectors. I'm not going to guarantee it will make it sound better but it usually does when they get rebuilt with regard to nailing.
 
Do you run any fuel additive? If not try some for a tank and see if it quiets them down. Clean fuel and an additive really helped mine stay quiet
 
I bought some liquimoly diesel purge the other day but have yet to run it through. I have a been using stiction eliminator for a couple of tanks, but it hasn’t quieted it up yet.
 
athensrep said:
I bought some liquimoly diesel purge the other day but have yet to run it through. I have a been using stiction eliminator for a couple of tanks, but it hasn’t quieted it up yet.
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stiction eliminator goes in the oil, it is for ford and cat engines that have HEUI injection.

diesel purge could have a benefit but diesel nozzles are a consumable wear item like brake pads. Also they need to be re-shimmed periodically.
 
Have you checked that the timing is correct?
 
No, that’s interesting - before I buttoned it up checked and rechecked and all was fine. Could it be a timing issue even though it runs fine at all other speeds and situations?
 
athensrep said:
No, that’s interesting - before I buttoned it up checked and rechecked and all was fine. Could it be a timing issue even though it runs fine at all other speeds and situations?
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Excessive diesel knock/clatter can indicate timing is out, I believe. That's the static timing of the pump, set by adjusting the plunger stroke on the injection pump (by rotating the pump slightly relative to the engine).
 
worn injectors will have a lower pop pressure. lower pop pressure effectively advances your injection timing. over advanced timing can cause nailing at certain rpm
 
I’m still chasing this, so I’ll keep this thread alive so hopefully it’ll help someone in the future. As an update, I changed the oil on my rig and checked the level for the first time in a month. The oil level was noticeably higher and felt a bit thin. I reckon I’m dealing with a dribbling injector. I’m going to do the paper test with the oil and make “sure”, but this has happened before on me with a Hilux.

I keep reading about dynamic timing as this may be an issue, but with the oil level rising a bit, can I safely assume this relates to an injector(s) that needs refreshing?
 
I've never seen the fuel dilution problem happen from a injection pump all the ones I've seen have been injectors. I have a set of core injectors id let go for cheap. I only sell rebuilt ones to trucks that are in the shop.
 
I’m a ways from you, so I may be interested in getting those off you.
 
Thoughts on this - was looking for any leaks and found at the fuel filter housing, after a couple of pumps it’s leaking diesel out of the top where the fuel heater is. Could the clatter/rattle be caused by sucking air?

image.webp
 
athensrep said:
Thoughts on this - was looking for any leaks and found at the fuel filter housing, after a couple of pumps it’s leaking diesel out of the top where the fuel heater is. Could the clatter/rattle be caused by sucking air?

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I would say very likely.
 
Ordered a new housing for it as putting new o-rings in did not do the trick to stop the leak.
 
New fuel filter housing (without the fuel heater) came in today. After installing it, hot soaking the injectors with seafoam, I took it on a spirited drive for 45 mins. while keeping the RPMs up. My impressions; it was hard for me to duplicate the “shaking nuts and bolts in a can” sound under load. The power seems a bit better and there were no issues. I did duplicate the noise somewhat, although it’s a bit more “dull” of a sound, less loud and less frequent. I could only duplicated when downshifting to 3rd gear and keeping RPMs above 2k but it would go away quickly and only was there with the push of the pedal - once I would let off, it quiets down immediately. I’m hoping it clears even more with a bit more driving, but seems to be some progress.
 
Update here in hopes this could potentially help one person someday. Rattle/nailing noise from injectors is gone after the long and hard run with a new filter and housing. Ran another half tank of diesel through it and it sounds great. For now, no more issues.
 
Mine clatters at 80kph and weirdly sometimes the clattering noise completely disappears on a cold day or at night time. Bought some liqui moly diesel purge additive going to try that. Diesel filter housing with the plunger button on the top is very soft, going to replace that.
 
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