The Heavy Duty Parts Report

4 Causes of Common Rail Injector Failures

June 10, 2022 Jamie Irvine Season 5 Episode 201
The Heavy Duty Parts Report
4 Causes of Common Rail Injector Failures
Show Notes Transcript Chapter Markers

Episode 201: Commercial fleets are focused on eliminating downtime, maximizing uptime, and lowering their total cost of operation. As technology changes new challenges arise. In this episode, we are going to talk about 4 causes of common rail injector failures.   

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 Jamie Irvine: (00:01)
You're listening to The Heavy-Duty Parts Report. I'm your host, Jamie Irvine. And this is the show where you get expert advice about heavy-duty parts that keep trucks and trailers on the road longer while lowering cost-per-mile.

Jamie Irvine: (00:15)
Commercial fleets are really focused on eliminating downtime, maximizing uptime, and reducing their total cost of operation. As technology on vehicles change, then some of the challenges change along with that technology. In this episode, we're gonna talk about four causes of common rail injector failures. And we're gonna really get into the details of that. Now my guest today is Robert Isherwood. He is the CEO of AMBAC International. AMBAC is a wonderful manufacturing company. He's been around for over a hundred years, actually 110 years. They specialize in fuel injectors and other engine-related parts. Now, Robert is a returning guest. He was originally on the podcast in Episode 46. If you want to go back and learn more about AMBAC, that's a great episode to listen to. He also updated us on some top trends in fuel injection in Episode 157 at HDAW this year in January. So if you wanna check out some of the top trends head over to Episode 157, and the links will be in the show notes for these episodes. So let's get Robert on the podcast. Robert, welcome back to The Heavy-Duty Parts Report. So glad to have you here. Third time on the show. Congratulations.

Robert Isherwood: (01:31)
Great to be back it's. This is a lot of fun.

Jamie Irvine: (01:34)
Well, I'm really looking forward to having the conversation last time you were on the show, actually, my guest host Tyler Robertson was filling in for me because of COVID restrictions. I wasn't able to be there in person. So that was, uh, awesome for Tyler to step up. And you guys did a great job talking about top trends today. We're gonna talk about four common causes of common rail injectors. You know, why they would fail what we can do about it. But first of all, let's talk a little bit about how this fuel injection technology differs from the iterations before it. So like what is a common rail injector and how does it differ from other types of injectors?

Robert Isherwood: (02:14)
Yeah, so let go even a little bit broader than that real quick fuel injector diesel fuel injector is really injects diesel fuel under extremely high pressure into the engine. The higher the pressure, the better the combustion is the more efficient the engine. So the older mechanical style fuel injection systems, they did a great job but they were relatively low pressure and therefore they were relatively inefficient. And you remember, you know, older diesels had a lot more black smoke, they had less fuel economy. Things like that. Common rail then is a technology where it's extremely high pressure up to 33,000 PSI and thereabouts. And the fuel pump is filling a rail, the common rail, literally, which is just a big pressure vessel of extremely high pressure fuel. And then it flows into the injectors. The injectors typically have an electronic solenoid or a switch that turns them on and off in the combustion cycle. And so you can turn them on and off multiple times in a combustion cycle, what we call an event. And then that gives you a long slow, very clean burn. So that's basically what a common rail injector is about. A long slow, very clean burn is very efficient, much better fuel economy and much lower emissions.

Jamie Irvine: (03:37)
Okay. So was this technology developed in conjunction with like higher EPA standards and aftertreatment systems, did they need to up their game in this, in this area? And that's kind of was the driver.

Robert Isherwood: (03:51)
Yeah. So the EPA does drive a lot of this kind of technology but really when you think about, you know, our focus and many peoples in the industry's focus is about cost per mile and lowering operating costs. When you look at at common rail, it does lower emissions and that's a benefit to society and a benefit to everybody. It also puts more money in your pocket because you burn less fuel, you make more money,

Jamie Irvine: (04:16)
Right. And you know, that is one of the big focuses of our show is to talk about making sure that people are buying the right parts so that they can lower their total cost of operation, total cost per mile. So are there any downsides to this system?

Robert Isherwood: (04:31)
Well, the thing that a lot of people run into, and it's not really a downside, but it's a difference in the, in the modern fuel systems, in the common, middle fuel systems as injection pressures get higher and the holes that they squirt the fuel through get smaller, they become fragile in a sense. And so then you can run into all kinds of problems related to your fuel injection system because of, you know, and we can talk about some of the things you can do to prevent problems, but essentially the more modern, more efficient systems are much more sensitive and therefore require a different level of care.

Jamie Irvine: (05:10)
Okay. That makes sense. So let's talk a little bit, you know, it's one thing to just say, okay, these things improve our total cost of operation, or they get our cost per mile down. Like how much, how much of a difference did this system make over the older mechanical systems?

Robert Isherwood: (05:27)
Well, you know, I'm not sure I remember back in the days when I was driving. But I remember, you know, you burned a lot of fuel and so you're talking about fuel economies that are significantly different. Anybody who's driven like an old Mackey seven from back in the day or anything like that will, can, you know, talk about miles per gallon or gallons per mile, more likely. And now, you know, the efficiency levels that we see in the fuel efficiency levels that we see in a modern fleet are really driven by a few things. But one of the major considerations is the advantages in the fuel injection system.

Jamie Irvine: (06:03)
I remember when I was a young man and, you know, loving big, big vehicles and a couple of my buddies got a couple trucks, and I remember being able to, you know, hit the accelerator and watch the RPM go up and the fuel gauge go down and it's just like unbelievable how inefficient those older systems were. I mean, created a lot of horsepower, but burned a lot of fuel.

Robert Isherwood: (06:28)
Yep. And a lot of black smoke. And so one of the things you can tell, if you're seeing black smoke that is unburned fuel and wasting money.

Jamie Irvine: (06:38)
Right. Just going straight out the tailpipes or the stack. Well, we're gonna take a quick break. And when we get back, we're gonna talk about these four causes of common causes of failures and what we can do about it. So we'll take a quick break. We'll be right back. Don't have a heavy-duty part number and need to look up a part? Go to parts.diesellaptops.com or download the app on Apple or Android to create your free account. Looking for high-quality fuel injection for heavy-duty applications. Having one supplier for fuel injection allows you to better serve customers by providing them with a complete line, which increases your sales and profitability. Learn more at ambacinternational.com/aftermarket. We're back from our break before the break. It was great to get a bit of a history lesson on how the common rail fuel injection systems were developed. And some of the reasons, some of the benefits, how they're improving fuel efficiency and lowering emissions. Now let's get into some of the common reasons the common rail injectors might fail. Let's start with filtration, how important is filtration?

Robert Isherwood: (07:45)
It's incredibly important. In fact, to be honest, we manufacture and remanufacture fuel injection systems. We don't sell filters, but the one thing I would always tell people to spend money on is filtration. Because that will save you a lot of heartache. When you think about it, the fuel's being charged up to 30,000 PSI, and then being forced through these tiny, tiny little, you know, thousands of an inch holes. So a piece of dirt, a speck of sand will destroy your fuel injection. A drop of water could completely wipe out a fuel injector. And that is really what causes internal erosion in the parts and the components of the fuel injection system. And then therefore poor engine performance, failure to start, failure to idle, all kinds of things like that happen. And the root cause on all of these things is dirt getting into the fuel and therefore into the fuel injector.

Jamie Irvine: (08:44)
Right? So filtration is critical. Let's talk a little bit about what actually happens when there's contamination. So for example, you talked about water. If you get in your fuel system that can lead to corrosion around the injector inlet and return, like how bad does that problem get? And just explain to us what exactly is happening there.

Robert Isherwood: (09:06)
Worst case it can actually blow the tip right off the fuel injector. So it'll break it. So imagine if you will like an injector, you know, a plunger pushing down on a valve seat and then fuel spraying out. So when that plunger is moving in the cylinder up and down, the space between the wall of the plunger and the wall of the cylinder, isn't in microns, we're talking about millionths of a meter, tiny, tiny. So anything that gets in there will start causing erosion and scoring just like a piston. Now at the bottom of a fuel injector is a ball. And that ball is a valve. That ball is tiny. Like you could hardly see it, it's so tiny, but that ball seating in that valve is the critical point of failure. And as that stuff, you know, dust or whatever, erodes the seat of the ball, then the ball no longer seats, the charge can't build up because you don't have a good clean seal. And then it kind of, instead of let's say injects, it sort of just dribbles, and you have unburnt fuel going up the stack.

Jamie Irvine: (10:20)
And I can see also one of the things I've learned, I mean, we've talked to a lot of people about aftertreatment systems, for example, and you know, one of the things you always have to look at with this is the complete system. And so this is where you're gonna get engine issues. You're going to get, you know, they talk all the time about upstream issues and downstream issues and making sure you're diagnosing the entire thing. So I can see that if you have all this corrosion going on, your engine's not gonna perform at the same level, and you're gonna create all these other problems in other systems.

Robert Isherwood: (10:50)
Yep. And sometimes injector problems will show up in hard to start issues, you know, sticktation on the smaller engines is a well known problem. And then sometimes it'll show up like, you know, your DPF will, and your DEF system will start choking and you'll have regens happening really frequently. And a regen is, you know, basically cleaning the soot, where did the soot come from? The soot came from poor compulsion in your engine and likely from an injector problem, so that your first sign, maybe why is this thing regening every single time I get in it.

Jamie Irvine: (11:24)
Right. So filtration is a big issue, it helps prevent things like corrosion around the injector, inlet and return. How often does improper installation play a role in injector failure as a remanufacturer you see a lot of the injectors and you get to tear them apart and analyze why they failed. How often is improper installation, the actual cause of the failure?

Robert Isherwood: (11:48)
Yeah, more often than you would want to see happen. And actually, you know, if you keep your trucks in reputable shops with well trained technicians, it doesn't happen very often, but it can happen and you can see it happening when you take the injector. So one of the interesting things is an improper installation. The injector may actually run and the engine will run rough or it'll misfire. And then you'll, you know, you might get an engine light or something like that, but it's running, but just not optimally. And when you pull it apart, you realize, well it wasn't torque down properly, or the there's a copper ring, a copper crush gasket. Sometimes we see where there's, they inadvertently put two crush gaskets, it's in the way you do that is when you take the old injector out, you have to look down on the hole and make sure you actually get the old and crush gasket out.

Robert Isherwood: (12:36)
If you don't, you put the other one on top of it. Now you have two and you know, all kinds of problems. When think about it, you know, the combustion event and a diesel engine is extremely powerful. The force of the fuel coming in is extremely high. So the tiniest little incorrect torque settings, or improper gasket or something like that. Now you have a leak path for all the combustion gaskets. And so you'll have, you know, literally fire, unburned fuel blowing up past the injector, and then, you know, all kinds of problems.

Jamie Irvine: (13:12)
Okay. So even if you get all of this correct, right, it's installed correctly. The filtration is right up to where it needs to be to keep, keep contaminants out of the system, we're avoiding corrosion. Therefore you still gotta start with the right part. So let's talk for a minute because I've heard, like I did some research ahead of this interview and I wanted to see what some of the, you know, the forums and some of the technicians were talking about, and I heard kind of the same theme repeated over and over again, which was that you should avoid reman parts, but I love remanufacturing. And I was a remanufacturer and I just knew that couldn't be correct. So can we correct that a little bit? And let's talk for a minute about the difference of avoiding a non OEM quality part, whether it's reman or new, because I think that's what really at the heart of what they were saying is low quality parts. So how do we avoid that? What should we be looking for? What denotes a high-quality fuel injection part.

Robert Isherwood: (14:11)
Yeah. And it's so important. I mean, it's important in everything, you know, from, from, you know, bumper to arm tires, to tires, to trailers, you wanna have high quality parts. And fuel injection, it's extremely important because the pressures are vastly higher and the tolerances are the most precise things in the vehicle. What happens is it costs, you know, fuel injection isn't cheap. And so people shop around and they find, you know, suppliers that come maybe from not so reputable sources or people that will they'll call it quote remanufactured. But what they really mean is they sprayed it with a garden hose, what we call fluff and buff. So they clean it off. They get the soot off of it, they throw it back in a box and they sell it again. At AMBAC and at many other high quality reman manufacturers, there are remanufacturing process happens in the same plant to the same quality standards as our OEM manufacturing process.

Robert Isherwood: (15:06)
We are an OEM fuel injection manufacturer for the U.S. Military and other organizations and have been for over a hundred years. This isn't something you learn in a day and you don't go down to your auto parts store and buy some degreaser and degrease something and call it remanufacture. That's really the difference and the quality and how can you know that you're dealing with the high quality remanufacture parts part of it you can tell in warranty. And for example, AMBAC has a two year unlimited mile warranty. Part of it, you can tell by reputation. And if you're in the industry for a little while you get to know the people who've been around for a long time, stick with the ones you know.

Jamie Irvine: (15:47)
Right. That history, that long history of high-quality manufacturing, it matters. So you've been listening to The Heavy-Duty Parts Report. I'm your host, Jamie Irvine. We've been speaking with Robert Isherwood, the CEO of AMBAC International. To learn more about their fuel injection program, go to ambacinternational.com/aftermarket, links are in the show notes. Robert, thank you so much for being on The Heavy-Duty Parts Report for a third time. Great to have you back on the show.

Robert Isherwood: (16:15)
Oh yeah. Jamie, thank you very much for having me. It's been a lot of fun and I look forward to doing it again. 

What are common rail injectors?
Are there downsides to this system?