Engine running rough after injector cleaning

[skipperpete]

To be perfectly honest, I’ve never given it much thought, I anneal copper tube for fuel lines and leave it to cool slowly because it’s too difficult to quench and only anneal copper washers when I don’t have a replacement but rarely anneal the thick injector nozzle washers, I always use new ones EXCEPT on Yanmars which frequently don’t have copper washers and have re usable hard washers with a very specific profile to fit the heat shield sleeve over the nozzle tip. These are mainly on the direct injection JH and LH engines and should not be heated to anneal them ( they’re not copper) nor should they be replaced with the copper washers that are usually provided by the fuel injection tech after an injector overhaul.
The bigger problem is that when the washer stays in the hole it goes unnoticed and another gets installed on top of it. That makes it very hard to diagnose some weird engine problems due to the corrupted spray pattern.

[Wotname]

<pedantic mode - ON>

1. If you are re-using old copper washers, not only have they work hardened when last fitted, they have also been deformed (slightly). After annealing, they become soft but still deformed so when next fitting, they need to be soft enough to deform again into a different profile.

2. Does engine vibration also cause them work harden?

<pedantic mode - OFF>

Heat and quench is good enough for gov. work

[Uncle Bob]

Originally Posted by skipperpete

To be perfectly honest, I’ve never given it much thought, I anneal copper tube for fuel lines ..........................

Mate, you have done it now,before you know it the experts will be here decrying the use of copper for fuel lines because it causes the fuel to gell and ..............

[skipperpete]

Originally Posted by Uncle Bob

Mate, you have done it now,before you know it the experts will be here decrying the use of copper for fuel lines because it causes the fuel to gell and ..............

Hahaha, they can take it up with AMSA, all fuel lines for surveyed vessels must be metal and only one short length of flexible hose allowed from engine bearer to lift pump, wire braided hydraulic hose at that. We only have a choice of copper or stainless steel…mild steel pipe on large diameter installations.
Peace![emoji4]

[s/v Jedi]

“Stuff on the net is wrong” …. Really?! Can someone define what “stuff on the net” is? When a university or big industrial company posts a document online it becomes “wrong”? How can one even come up with such statements?

So I read that document and it explicitly says you can quench in water as well as in air but in case “further manufacturing stages” are required, such as drawing through a die or other cold forming, then a slow controlled cooldown inside an oven is recommended. That is of course completely out of the context of my recommendation done for copper washers for the Yanmar.

If you simply Google for “annealing copper” you get many links from many reliable sources that all say to quench it in water and you don’t get the link that was posted. To get that you really need to search for annealing with slow cooling.

If I search for “kissing an elephant” I am sure one of the first hits will show that this has been done, but that doesn’t mean it will pop up when searching for “what to do with elephants “

Anyway, the OP fixed the problem by opening the fuel valves and knows how to anneal his copper washers even without controlled temperature ovens

[betwys1]

Originally Posted by sv_isara

Hey all, so in a fit of madness (and because i have persistent white smoke and a slightly lumpy idle when cold), I removed all 4 injectors from my yanmar 4JH2E and cleaned them - just soaked in injector cleaner and wiped off carbon.

Then here's what happened: I reinstalled. Engine ran lumpy with cylinder 4 leaking diesel (rear cylinder). I removed and reinstalled the injector. No leak. Ran quite smooth for maybe 30 seconds, and then very very lumpy, and maybe knocking. It actually died when left at idle. Still smoke, maybe even moreso.

Now, I didn't have new copper orings which are on the way from ebay (who knows how long to ship). What would be my next steps here? Take the >$1k plunge for new injectors? Get a shop to rebuild them? Run the engine longer? I'm trying to leave in a few weeks...

Thanks for any help.

When the new sealing rings arrive, try to put the injectors back in their original order.

[arcticmonkey]

Been out of the game for a while but last I remember the copper rings were cheap enough.... start fresh.... stay fresh

[Tillikum]

Just for future reference by others, it you clean your injectors in that way, or run injector cleaner through your fuel tank and the engine starts running rough, you have probably dislodged some particles of "gunk" in your fuel lines or injectors which have then plugged or partially plugged some of the injector nozzle holes. If such a problem doesn't resolve quickly better pull the injectors and have them cleaned, tested and the opening pressures reset by a proper injection shop.

Injection shops use ultrasonic cleaners for injectors and injection pumps, so if you want to work on your own, get one. Proper injection shops are also kept VERY clean and organized, for good reasons.

Contamination in the fuel is major reason for injector nozzle wear. Wear can lead to deformation of the holes in the injector nozzle, which can result in poor spray patterns, or even more of a stream than a spray! I saw an aluminum piston where a concentrated spray or stream of fuel had actually burned through the edge of the piston, past at least two rings, causing a complete lack of compression in that cylinder. Dislodged "gunk" could also cause uneven or incomplete spray patterns.

If you don't possess a heavy piece of plate glass or a granite surface table/counter top, and some 600+ grit emery paper, to lap injector sealing washers on, better just to buy new ones. Without sufficient manual skills it's easy to lap the top and bottom surfaces of the sealing washer out of parallel with each other, and then no proper seal.

Grit or dirt falling into injector ports between removal and refitting of injectors can also prevent a proper seal, as well as damaging the pistons & bores, so clean off the area around and above the injectors before disconnecting anything with compressed air, and a solvent if required. Put some tapered rubber bungs or clean pieces of rag in the holes while the injectors are out.

DO NOT USE CARB CLEANER! Any residues of carb cleaner, and probably similar solvents such as MAP sensor cleaner, will turn into Phosgene if heated past a certain point and even tiny amounts of that gas will wreck you permanently if inhaled.

In short, take every reasonable measure to keep your tanks and fuel clean, and have injectors rebuilt periodically. A sub-micron filter on the fuel line is the cheapest insurance.

[Icarus]

Originally Posted by sv_isara

Hey all, so in a fit of madness (and because i have persistent white smoke and a slightly lumpy idle when cold), I removed all 4 injectors from my yanmar 4JH2E and cleaned them - just soaked in injector cleaner and wiped off carbon.

Then here's what happened: I reinstalled. Engine ran lumpy with cylinder 4 leaking diesel (rear cylinder). I removed and reinstalled the injector. No leak. Ran quite smooth for maybe 30 seconds, and then very very lumpy, and maybe knocking. It actually died when left at idle. Still smoke, maybe even moreso.

Now, I didn't have new copper orings which are on the way from ebay (who knows how long to ship). What would be my next steps here? Take the >$1k plunge for new injectors? Get a shop to rebuild them? Run the engine longer? I'm trying to leave in a few weeks...

Thanks for any help.

Get the injectors serviced and new seals.. Any diesel service shop can do it.

[sinnerman]

IMHO, I don't think cleaning the injectors externally will do much for them.

In a worse case scenario if you are scraping off carbon, you may damage the injector's "pin".

Injectors need to be tested every few years. the test involves:

- Verifying the spray pattern is correct (a cone of mist and not a squirt)
- Verifying the injector "fires" at the correct pressure setting
- Checking to see that after the injector fires, it is not leaking (dripping) while still being held under pressure

You can make your own injector tester from a small hydraulic jack.

There is a Mercedes guy who sells a kit...
https://mercedessource.com/store/die...do-it-yourself

there are cheaper versions available online, including from China-zon..

my two cents

cheers

[s/v Jedi]

I use one like this for testing my Yanmar injectors: https://www.amazon.com/dp/B072F2JDJV

[Iron E]

Hard to believe that OP has found his problem, and you folks are still talking injectors... aren't you the least bit interested in kissing elephants?

[s/v Jedi]

Originally Posted by Iron E

Hard to believe that OP has found his problem, and you folks are still talking injectors... aren't you the least bit interested in kissing elephants?

This isn’t a question answering service, this is a discussion forum and there will be plenty of future readers who appreciate the info posted here.

Your contribution however has been minimal and what there is, is completely off topic and not helpful for current nor future readers