Does Toyota Direct Injection Cause Carbon Build Up? Let's Find out!

hello and welcome to the car care Channel and welcome to this 2017 Sienna that we're working on here but we're not really going to talk about the Sienna we're going to talk about Toyota's d4s direct injection system so in this video we're first going to explain what that system is and then we're going to see if it actually works for its intended purpose let's get started and you'll see what's what let's talk about Toyota's d4s system so this system came out right around 2017 in Toyota models in the Lexus side has been going on for a little longer so basically modern cars they're using direct injection direct injection has a lot of benefits mainly for emissions higher performance it's just a better system you inject the fuel directly inside the combustion chamber that way you don't have to waste a lot of this fuel going down the intake and the runner is just more precise you can spray the fuel exactly where you need it when you need it and it's immediate now with direct injection there's a lot of challenges one of them is how do you make a perfect spray pattern the only way they do that is you have to overcome the compression pressure by a lot not let's say compression pressure 200 PSI somewhere around there the direct injectors have to spray at such higher pressure so the pattern will be perfect not just over 200 it'll be dissipated all over the place so these systems can run up to 3 000 PSI that's the thing but the biggest thing with direct injection is it has one downside see port injection which is basically what we're used to with fuel injection since it came out it is its price inside the intake manifold and then it kind of goes to the back of the valve and into the combustion chamber as the engine is pulling the air charge it pulls the fuel with it and that's how you get the fuel delivery but that has a secondary kind of objective or secondary thing that it does it actually cleans the back of the valve because that fuel passes over the intake valve and goes inside the combustion chamber and direct injection only cars that does not happen so over time there will always be some oil inside the intake that's just normal blow-by PCV system that is normal that oil eventually cakes on the intake valve and we have severe carbon buildup that unfortunately is a problem with direct injection cars they all suffer from it some of them not as much as others your driving kind of habits really have to do with it but in this system you have both it's kind of like The Best of Both Worlds you have the port injection which in some cases is actually useful to have which also watches the washes the back of the intake valves then you have direct injection which gives you the benefits of that precise fuel delivery inside the combustion chamber so that's basically what the d4s system is you have both having said that let's take a look at some of the components that make the system the first one is your fuel injectors these are the port injectors there's three of them here three of them here and you notice they're attached to the intake manifold and then underneath the manifold you can kind of see it on the edge here there's two more rails that make the direct injection so the thing is your regular fuel pump in the fuel tank it only has what 40 50 psi it can go maybe to 80 if you push it that's it how are you going to make that 80 psi to up to 3 000. well this car has two fuel pumps one of them is electric one in the tank they all do have it that gets the fuel from the tank to the front then it breaks off into two sections and we can actually see those sections you see one of the fuel lines comes here and goes to the rail and then there's a cross pipe between the two rails that is business as usual 80 psi up to 80 psi to feed the port injectors but then the second fuel line right here that comes from the same fuel pump in the tank goes to the high pressure fuel pump right here this high pressure fuel pump is actually sitting on the valve cover and it's driven by the camshaft it is a mechanical fuel pump it is controlled by the computer right here you see a solenoid to control the pressure now from that you notice there is a metal pipe and the reason it is a metal pipe is because of the high pressure these pipes are one-time use you only can use these pipes once and this goes to the rail and then there's another metal pipe right here this metal pipe passes the fuel from one rail to the other so now we have that high pressure fuel spread around the rails that is in essence the components of the high pressure fuel system now you do have pressure sensors so it would know where the pressure is at at any given point but really that's about it but there is something important about the direct injectors and their service so the port injectors they do have seals if the seals are damaged on the rail side so on the upper side they will leak fuel if the seal is damaged on the bottom side you'll have a vacuum leak hardly the big issue I mean normally when you service them you replace the O-rings at the top and the seal at the bottom life is good but direct injectors if they leak you're going to be leaking combustion it's almost like you are going to lower the compression it's almost like you have a no spark plug and you're trying to start the engine so sealing these is super important they have multiple seals one of them is a Teflon seal that is a one-time use you may basically remove one of these it's garbage you have to replace the seals there's no way around it and direct injectors because they are such high pressure and very precise they're actually calibrated from the factory now in the case of Toyota they have a number on them and that's how you when you go replacing them you got to look at that number and get a similarly calibrated injector but you have to replace the seals but say you have one injector that is bad you removed the rail in the case of this 2grfks you have three injectors on each rail you have to remove the entire rail to replace one injector the one injector will come with new seals but the other two you need to replace the seals it's a very intricate process to replace them require special tools and you have to be very careful because when they leak they not only leak compression they also leak fuel at a rapid rate because remember they are running at very high pressure here so that is kind of the gist of the operation of the system of course it's all computer controlled works pretty good so far let's talk about their reliability a little bit before we talk about do they actually work reliability so far has been decent and I say decent because there has been cases where an injector causes issues kind of fuel contamination causes a lot of issues these can be sensitive make sure you're using good fuel and good fuel doesn't mean premium in the case of the senator example it means top tier fuel use fuel that is good quality don't use the cheapest fuel you can use because these direct injectors they're a little bit sensitive high pressure kind of extreme environment that they work in so using good fuel is important but here are the problems that I've seen from experience with fuel injectors with Toyota high pressure fuel pumps not exactly problematic there has been a case or two maybe of them getting a little louder than usual a few oil leaks not really fuel leaks from the line unless they've been mishandled or not properly installed but the fuel injectors we've had cases where they leak from the from the factor all of a sudden just bring a leak the second thing is they don't spray properly and then you have kind of random misfires or air fuel ratio imbalance because one of these injectors is not spraying properly and then the rest of the three are and the computer looks at it like wait I have an imbalance one cylinder is not getting the numbers that I wanted to because the fuel injector is not doing its thing these are really about the problems the injectors are super expensive and this is the problem with them because they're such high quality something with Toyota most other injectors are not plastic they're actually full metal some of them are the older ones especially the Lexus side but the newer ones they're all metal most other manufacturers they're all plastic and plastic heat and pressure they don't get along let's put it this way now having said all that did this actually work the idea of work for us the consumers all the marketing Gizmo and Engineering stuff of oh yeah there is a benefit to port injection and all that sure yes but the bottom line is does this engine build carbon this engine has just over 80 000 miles we're replacing spark plugs for the first time you have the plenum off we actually have a view of the intake valves so let's take a look this is going to be hard to show and I'm going to try my best if not we'll just get you guys a video of this but basically these are clean valves see him right there these are not carboned up at all here's a view of the other one there there we go that's a good shot these have zero carbon my friends so that means the system is actually working and this is what's what the promise is that you get the idea this is working and for service just for those who are interested this is the high pressure fuel pump there's not real precautions about removing it basically most of them have two bolts see one of them right here and the other one in the back you got to be careful with these pipes you have to discharge the fuel and that requires a scan tool when you take this fuel line off ideally replace it every time because these are kind of compression fittings and you do want to replace that line every time or at least torque it the spec and a little bit more when you're reusing it ideally don't reuse it but if you must that's fine this fuel line that comes from the fuel pump the low pressure fuel pump nothing really about it connector right here for the solenoid that controls it but the main thing is when you remove one of these this has like a cam lobe and the at the bottom of it you want the lobe to be on the flat side so this wouldn't jump up and be really hard to install and the fuel injectors themselves they're hard to show see part of the rail right there and you can see the side of it right here but the same thing we have that other line right here this line is the crossover between the rear bank and the front Bank rail and then on this side it's really hard to see but something that Toyota loves to do and I really like it these two connectors are actually that connectors for the coil for the fuel injectors so kind of have one Bank two bank very easy to disconnect and it's a separate harness because remember the wires that go to these injectors are under extreme extreme pressures I mean the heat the kind of the area that they're in something in the older cars knock sensors used to be but are still there but knock sensors wires used to deteriorate and now you have to take everything and and in the old cars they used to be separate a separate harness and newer ones not so much on this one however the injector wires or the harness for the injectors is a separate wire than the rest of the wiring harness so basically if the connector is all brake and deteriorate or you have rodent damage whatever you can just replace a small piece of wire and that's it we're not replacing the entire engine harness that is good thinking folks from experience and not just from this car from other cars the system actually works and Toyota is not the only manufacturer that has done this there has been other manufacturers that have done this system and have worked for them as well people really dislike GDI or direct injection GDI by the way stands for gasoline direct injection Toyota does not use that that lingo that's more Hyundai or other manufacturers but direct injection can work and people don't they really dislike it and they see it as a problem well it's not a problem here 80 000 miles I understand this is not high miles but still I've seen cars with 20 000 miles that direct injection only they're already carboned up casing Point Mazda if you drive it the wrong way basically short trips repeated short trips repeated it's going to build up carbon at a rate that is unbelievable here we have nothing and that's the whole point folks cars are only getting more complicated yes would it be nice to only have port injection make this engine super simple yes but in order for this engine to function in the baron days emissions wise they have to do this I don't think Toyota wants to do this complication they spend all this money in research and development and all that and all other manufacturers by the way but this system at least Works where you don't have to pass emissions but have all kind of problems down the road with carbon buildup there's no carbon buildup this is good however and this is this is a very important note even non-direct injected cars can build up Carbon on the valves on the Pistons on everywhere if you don't drive them properly and let's talk briefly before we wrap up the video about that how do you keep your inside of your engine clean from carbon number one change your oil on time I know you think why does this have anything to do with that blow-by folks PCV system oil will end up making its way inside the intake that is normal with gasoline engine so changing your oil on time using good quality oil helps a lot the second thing is avoid short trips I mean there is nothing that destroys a car more than not driving it and worse driving at Short distances I mean by the time you start the car the engine has not really warmed up the oil hasn't really warmed up so you drive it a very short period of time you shut it off guess what hap just happened you have all kinds of fuel in the cylinder you have all kinds of fuel all over the place and on top of it you have that thick oil that's now sitting in the intake and it just sits there and cakes never gets a chance to really warm up completely for some of that fuel to evaporate some of the oil to start moving for the PCB system to work properly that's the one thing that builds carbon folks Italian tune-up is not a myth every once in a while if you let's say drive around time you don't really drive fast you don't really push the car once every month taken on the highway and literally stand on the throttle and just blow all this stuff out of the exhaust because it does help this is important folks I hope this information kind of puts you at ease if you have one of these systems and secondary helps you kind of understand what to not do when you have one of these systems or for that matter really any car avoid them short trips and if you do have no other choice make sure you're maintaining your car accordingly maintenance moves by time when you are kind of doing short trips and that severe driving condition folks I hope this video is helpful informative I hope you learned something new if you like it consider giving a thumbs up if you're not a subscriber consider subscribing to the channel check out some of my other videos until the next video folks may the Lord bless you and keep you and you have yourself a wonderful day

Channel: The Car Care Nut

Views: 133,449

Keywords: Toyota direct injection, gdi, gdi carbon build up, new car problems, modern car problems, toyota, toyota reliability, toyota problems, direct injection carbon build up, direct injection problems, fuel injection problems, car longevity, car, car repair, car reliability, engine, engine fuel injection, modern engine, toyota engine, 2gr-fks, toyota d4s, d4s, the car care nut, car care nut, scotty kilmer, car wizard, south main auto, rainman rays, toyota port and direct injection

Id: vrofW73ZKxw

Length: 16min 47sec (1007 seconds)

Published: Wed Mar 01 2023