Understanding Injector Trim Codes?

[Makers Acres]

Hello all!
For those following my other posts, I am having to replace a couple of injectors in my CAT 299D 3.8 turbo engine / Kubota V3800T.

I am trying to understand the injector trim codes in order to save some money here and I hope that some of you might be able to explain a few things.

Part of the process of installing new injectors is installing the trim codes that are on top of the injectors into the engine ECU. This will cost about $1200 for the dealer to do. That’s just the programming, not the injectors. This is maybe a five minute job so I have a really hard time justifying that.

So I really want to understand what the consequences are of not installing the new trim codes are?

Alternatively, how close are the trim codes to one another and would I be able to find a trim code that is close to what was already installed and call that good? This is assuming that the place I buy the injectors from will let me dig around and look at the numbers on the injectors they have in stock.

Does anybody know how the injector trim codes break down and what they mean?

Thank you.

 

[pumkinhead]

 

[Nige]

Does anybody know how the injector trim codes break down and what they mean?

Only the factory know that. In all my years working with equipment I have never come across anything like a "how to decipher Trim Codes" document.

The best way I can explain it (from what I know) is that every electronic injector behaves differently as regards the function of the energization/de-energization of the solenoid coil and also the response time of the internal mechanical parts. When each injector is tested after being built its electronic/mechanical performance is compared to a known standard, and on the basis of the test results a Trim Code is assigned to it in order to make that injector perform exactly as per the "standard", so to speak.

Once installed into the engine ECM, the Trim Code assigned to a particular injector will fire that specific injector either slightly more advanced or more retarded (measured in milliseconds) compared to "standard fuel injection timing". The Trim Code will also cause the ECM to fire the injector for a shorter or a longer duration, again compared to the "standard".

 

[Makers Acres]

Only the factory know that. In all my years working with equipment I have never come across anything like a "how to decipher Trim Codes" document.

The best way I can explain it (from what I know) is that every electronic injector behaves differently as regards the function of the energization/de-energization of the solenoid coil and also the response time of the internal mechanical parts. When each injector is tested after being built its electronic/mechanical performance is compared to a known standard, and on the basis of the test results a Trim Code is assigned to it in order to make that injector perform exactly as per the "standard", so to speak.

Once installed into the engine ECM, the Trim Code assigned to a particular injector will fire that specific injector either slightly more advanced or more retarded (measured in milliseconds) compared to "standard fuel injection timing". The Trim Code will also cause the ECM to fire the injector for a shorter or a longer duration, again compared to the "standard".

Thank you for the info and thank you for all the help you provided on the forums!

 

[ozarkag]

Takes a bit more than 5 minutes, maybe 15 if everything goes smooth AND you have a record of the trim codes and which hole they're in.

 

[HarleyHappy]

Love the idea. Went through pretty much the same thing, when HD went to fuel injection.
Instead of having a letter drill bit index and a bunch of jets, we had to buy Power Commanders and all the other EFI controllers, to find and fix fuel tables and everything related to that stuff.
My brother found a way to break the marriage process on controllers, so they could be used on other bikes.
Good luck on your quest and hope you succeed!
Its insane to pay that kind of money, when you know, most of the people doing the work, have no idea what they are doing, just following a menu feed program and a little data entry.
I am surprised, that there are no aftermarket options available at a reasonable cost.
Might be a good business venture?

 

[Birken Vogt]

I'm pretty sure there are a lot of hillbillies around here with injectors swapped without even knowing what a trim code is.

Then there are the Chinese where the trim codes might all be the same on a group of injectors.

I can't see how it would make a whole lot of difference outside of wide open throttle/full load situations, especially on an engine that does not run many hours.

 

[1466IH]

I'm pretty sure there are a lot of hillbillies around here with injectors swapped without even knowing what a trim code is.

Then there are the Chinese where the trim codes might all be the same on a group of injectors.

I can't see how it would make a whole lot of difference outside of wide open throttle/full load situations, especially on an engine that does not run many hours.

I have changed injectors on various brands and types of equipment in the past without entering codes and only 1 time was it ever an issue. It really wasn't even an issue and the tractor ran great and had no loss or power or any symptoms other than a very slight flutter at idle that went away at higher RPM's. Installed codes and flutter went away. Now that I have acquired the correct tooling and software over the years I always update codes. All I can suggest is go ahead and get the injectors installed yourself and see how it acts. If you notice something isn't quite right you can haul it in to the dealer so you don't need to pay a service call charge.

 

[Nige]

If you notice something isn't quite right you can haul it in to the dealer so you don't need to pay a service call charge.

It was covered in another thread. His dealer has a 4-hour minimum labour charge (somewhere around $800) even if the machine is hauled to them. 4 hours for what should be a 15-minute job is a rip-off IMO.

 

[1466IH]

It was covered in another thread. His dealer has a 4-hour minimum labour charge (somewhere around $800) even if the machine is hauled to them. 4 hours for what should be a 15-minute job is a rip-off IMO.

I saw that but just assumed that was just for field service. I would like to know what mother cat thinks of that and which dealer it actually is. He could probably pay an independent mechanic in his area to come install the injectors start to finish for that price.

 

[92U 3406]

$1200 to program injectors? Are they on glue?

 

[Birken Vogt]

Maybe just install them now "good enough" and record the numbers. Get them programmed later whenever you have a mechanic with a laptop or hand held tool on site for some other reason.

 

[Makers Acres]

Love the idea. Went through pretty much the same thing, when HD went to fuel injection.
Instead of having a letter drill bit index and a bunch of jets, we had to buy Power Commanders and all the other EFI controllers, to find and fix fuel tables and everything related to that stuff.
My brother found a way to break the marriage process on controllers, so they could be used on other bikes.
Good luck on your quest and hope you succeed!
Its insane to pay that kind of money, when you know, most of the people doing the work, have no idea what they are doing, just following a menu feed program and a little data entry.
I am surprised, that there are no aftermarket options available at a reasonable cost.
Might be a good business venture?

There are a lot of Chinese knock offs of these injectors, but I don't think I am ready to go that route. They might work, but I want someone else to try it on there engine first

 

[Makers Acres]

I saw that but just assumed that was just for field service. I would like to know what mother cat thinks of that and which dealer it actually is. He could probably pay an independent mechanic in his area to come install the injectors start to finish for that price.

This is a Quinn Cat Dealership. They are catering to large corporations that have lots of money and are willing to pay any price to get something repaired.

For what it's worth, I happen to cross paths with a CAT service tech that was leaving work and I tried to talk to them about the problem, and though he was nice, I was brushed off.

 

[Makers Acres]

Thank you all for the great info. I am going to try the new injectors and see what she does!

 

[Nige]

I am going to try the new injectors and see what she does!

Two things if I was in your shoes.
Seeing as 50% of the original injectors failed testing I would replace all four.
I would replace them with genuine Kubota OEM ones, most probably from a Kubota engine dealer because their prices will be better than Cat. The Kubota Part Number should be right on the top of each one.

 

[DDoug]

Interesting on the large diesel engines (4000 hp) one OEM
has pressure xducers in the head, and when a new power assembly
is swapped in (and presumably injectors as well) the engine computer
is set up to read the firing pressure (some sort of test mode), and adjust "things".

 

[Makers Acres]

Two things if I was in your shoes.
Seeing as 50% of the original injectors failed testing I would replace all four.
I would replace them with genuine Kubota OEM ones, most probably from a Kubota engine dealer because their prices will be better than Cat. The Kubota Part Number should be right on the top of each one.

Thank you. I did in fact source these from a Kubota dealer and they were $599 each instead of $860 at the Quinn CAT dealer.

I agree with you. I would love to replace all 4, but that is a hefty price. I talked to Area Diesel Service (Who tested the injectors) and tried to feel them out about the 2 that were running. I asked them if I had the money, would I want to replace all 4 right now, and they said the 2 good ones are still in spec and still have life left in them. So I don't know. I may change my mind again.

Keep in mind I have owned this machine since 2018 and in the 7 years I have owned it, I have put on 500 hours. I bought it with around 3400 hours and I just crossed 3900 hours. I am only putting on about 72 hours per year.

 

[Nige]

Keep in mind I have owned this machine since 2018 and in the 7 years I have owned it, I have put on 500 hours. I bought it with around 3400 hours and I just crossed 3900 hours. I am only putting on about 72 hours per year.

I get all that, but how much money are you gambling with by only replacing two injectors compared to the cost of a replacement engine if worst-case scenario comes to pass.? A catastrophic injector failure can easily leave you with an air-conditioned cylinder block. All the people giving you advice here will have seen that multiple times over the years. At that point it's Good Night Irene.....

 

[Makers Acres]

Yep, after my last post, I bit the bullet and ordered the other two injectors! Thanks @Nige for that. hehe!