Interpreting numbers stamped on injector

[JohnDB]

I pulled the injectors to check the head clearance, do a compression & leakdown test, and have a look at the injectors themselves. 5 of the 6 injectors are stamped "1570" and "S1", but one is stamped "1570" and "S2". Can anyone please tell me the difference if any between an S1 and an S2? Does it matter that they aren't all S1? The engine is an S2600 in a M4500DT. (Dealing with all those cylinders... suddenly I can see the attraction of 3 cylinder tractor engines, compared to 6...)

Thank you.

 

[thepumpguysc]

No, it doesn't matter..
What DOES MATTER is> is the correct nozzle in it.
If your going to take it apart, the nozzle nut MUST be torqued 50-55FTlbs
If your worried about it, take the 2 apart.. BUT if your not experiencing any skipping or missing, leave them alone.
Curiosity killed the cat.. and blew-up a good engine.. Lol

 

[JohnDB]

Thanks! I'd been wondering if the S1/S2 difference might have been the cause of the engine not running as smoothly as I'd thought it should. The compressions and leakdown don't show any significant issues, so I was looking for reasons in the injectors. I can't find any information on reading injectors, like you can for reading spark plugs. Here's what mine look like with mirror images

 

[JohnDB]

There's more variabilty between the injectors than I would have expected... but I'm no expert. What do you think?

I can take more photos if needed, but here are some close-ups"

 

[SidecarFlip]

Not being an expert on injectors, the difference in my view is flame pattern.

 

[JohnDB]

Thanks Flip, so maybe I need to be thinking about injector work.

Thinking about SCpumpguys comments, aside from not running smoothly it seems like when it's starting from cold (with glowplug preheat), for the first one or two crank rotations it sounds like a couple of cylinders are firing, but aren't enough to get the rest going, and it takes another one or 2 rotations before the engine fires up. When it's warm, no problem starting.

Does anyone know of a good thread about cleaning these things? Or is that unlikely to make a real difference and the flame pattern is a symptom of a bigger problem? The engine has done 5000 hours, I don't know if it's ever had the injectors out - no visible signs to indicate that they have been pulled before. Or should I give up and get a shop to look at them. Problem is, local shop says NZ$100 (US$65) per injector to service so it's a decision I can't take lightly.

 

[SidecarFlip]

Sounds pretty reasonable to me price wise for a bench test for spray pattern and a rebuild. With 5K hours on them I bet the spray pattern has degraded some. problem is, if an injector goes south you'll wash that cylinder and then you'll have major engine work as well.

 

[thepumpguysc]

Theres really no good way to clean the injectors other than a sonic cleaner or lapping compound..38-1200.
DO NOT run the nozzle across a wire wheel..EVER.
& u need a pop tester to check/set the opening pressure..
U can check the spray pattern by hooking one/all up to the lines, upside down w/ the tips in the air & spin the engine..
DO NOT get close to the spray!!!! IT WILL penetrate your skin if u get close.
IF your really concerned over the stamped #'s.. Take 2 diff. ones apart..
just re-torque the nut when satisfied..
The nozzles have manuf. #'s stamped on them.. See if they're the same.

 

[JohnDB]

Thanks guys, looks like its a job I'd better get the injection shop to do.

All 6 injectors have ND stamped on them and "1570", all are S2 except the rogue S1.

If a cylinder gets washed for any length of time, does the surplus diesel add to the oil level appreciably? How will I know if a cylinder is washed bad - low compression?

 

[JohnDB]

To wrap up the story: got the injectors serviced - apparently 4 had virtually no spray pattern, just raw fuel, one had a bad spray pattern, and one had a more-or-less OK pattern. Pressures were "a little low". Shop says that there's no sign that the injectors had been serviced previously - apparently shops here usually mark (engrave) the injectors they service. New nozzles supplied. Installed the injectors, tractor seems to start easier and definitely has more torque - I don't have to change down to get up a particular slope where previously I had to change from 3rd to 2nd. I still can hear a slight chuffing noise, sounds like in time with a cylinder firing, only when under load, and only if I have earplugs in. Without earplugs it sounds fine (if you ignore the overall noise . So I may be paranoid, it may be simply some sort of harmonic in the exhaust system... or not.

Thanks to everyone who contributed.

 

[thepumpguysc]

Thanks for the update John.. sorry u weren't closer.
BTW> what is the going rate for your injector overhaul.?? Converted money please.

 

[JohnDB]

Yes, the tyranny of distance Price was US$67 per injector, excluding sales tax of 15%.

 

[sanjeevtyagi]

I pulled the injectors to check the head clearance, do a compression & leakdown test, and have a look at the injectors themselves. 5 of the 6 injectors are stamped "1570" and "S1", but one is stamped "1570" and "S2". Can anyone please tell me the difference if any between an S1 and an S2? Does it matter that they aren't all S1? The engine is an S2600 in a M4500DT. (Dealing with all those cylinders... suddenly I can see the attraction of 3 cylinder tractor engines, compared to 6...)

Thank you.

Hi John , How easy or difficult is it to take all the 6 injectors out? I just had a newbie question to you , if you suspected about the injectors being blocked why didn't you go the new injectors route which seems to be pretty cheap about $33 per injector, I am very new to tractor world as you know so i might take some learning from this thread.

 

[JohnDB]

Hi John , How easy or difficult is it to take all the 6 injectors out? I just had a newbie question to you , if you suspected about the injectors being blocked why didn't you go the new injectors route which seems to be pretty cheap about $33 per injector, I am very new to tractor world as you know so i might take some learning from this thread.

Hi Sanjeev, removing them is easy enough if you have the right spanners and sockets. The Nanni engine manual shows the sizes needed, torques. To avoid damaging the nuts I used a slotted socket, like the manual shows. I decided to get the injectors overhauled rather buy new knock-off ones of unknown parentage You'll need new copper seals when you reinstall.

 

[sanjeevtyagi]

Hi Sanjeev, removing them is easy enough if you have the right spanners and sockets. The Nanni engine manual shows the sizes needed, torques. To avoid damaging the nuts I used a slotted socket, like the manual shows. I decided to get the injectors overhauled rather buy new knock-off ones of unknown parentage You'll need new copper seals when you reinstall.

Thanks John , So if i bought the OEM ones i can seat them without any tuning required ? I will try to follow your lead if the injectors can be cleaned otherwise i will buy new ones and replace as per your advice, thanks a lot.

 

[JohnDB]

Thanks John , So if i bought the OEM ones i can seat them without any tuning required ? I will try to follow your lead if the injectors can be cleaned otherwise i will buy new ones and replace as per your advice, thanks a lot.

I've had a look at your other posts and feel that replacing injectors may be premature and not help at all. Also, your reference to seating the injectors without tuning required has me puzzled, I simply can't comprehend what you mean there by that phrase. If the amount of blowby is as large as you indicate in other posts, I'd speculate that the engine has serious issues. I suggest that you video the engine and blowby when it's operating so forum members can get a clearer understanding of the condition of the engine.

If you really want to pull the injectors then I'd suggest you test them as per the Nanni marine engine manual, and clean them also as described in the manual. Also I saw your post attached to Fishfarmer's thread, and I can't work out what you mean by "it was starting with starting smoke" so some clarification on that post might help get good answers. Finally, re your question about the 15W-40, I doubt that oil grade would prevent the engine starting. Which brings me back to the point above: it would seem that the engine has serious issues and you would be better to follow some of the diagnostic-related advice already offered by forum members, I think in amongst it compression testing was suggested and I'd definitely do that, or leak-down testing, before spending more money on the engine. The Nanni manual also has troubleshooting advice.

Best of luck, please keep us posted.

 

[North Idaho Wolfman]

Thanks John , So if i bought the OEM ones i can seat them without any tuning required ? I will try to follow your lead if the injectors can be cleaned otherwise i will buy new ones and replace as per your advice, thanks a lot.

If it's the engine I think it is You can not get OEM injectors, there is none avalible.
I'm with john, I don't think injectors are going to solve your problem.
But If you wanted to do anything with the injectors send them to Oregon Fuel Injection, they will rebuild them properly.

 

[sanjeevtyagi]

If it's the engine I think it is You can not get OEM injectors, there is none avalible.
I'm with john, I don't think injectors are going to solve your problem.
But If you wanted to do anything with the injectors send them to Oregon Fuel Injection, they will rebuild them properly.

Thanks Wolfman and John , It is the S2600-A Engine Wolfman , I will follow some baby steps one by one and see what i can diagnose going forward. Cannot rush into it as you suggested