Throttle body injector for intake valve cleaning?
02-05-2018, 04:20 PM
#1
Throttle body injector for intake valve cleaning?
Toyota DI engines also have port injection. A major advantage of this is the intake valves get washed down with fuel, which tends to keep them clean. Other brands, such as Honda, don't do this.
How feasible do you think it might be to rig up a single injector somewhere in the intake that, when activated, would spray in gas from a separate tank that is HEAVILY fortified with a fuel injector cleaner like techron? Every oil change or so, run a liter or so through to keep the intake valves clean. Perhaps it's a slow trickle and you have it idle for 40 minutes and that's what's primarily running the engine, or perhaps you have it run while you're on cruise control on a flat freeway.
The only risks I can think of are degrading the MAF sensor if it's in front of that (my first idea was to pour a little Techron right on a fresh air filter and let it evaporate as you drive) or, if it's low octane and you put your foot in it, engine knock. Thoughts? How bad is carbon buildup on higher mileage 3.5's?
How feasible do you think it might be to rig up a single injector somewhere in the intake that, when activated, would spray in gas from a separate tank that is HEAVILY fortified with a fuel injector cleaner like techron? Every oil change or so, run a liter or so through to keep the intake valves clean. Perhaps it's a slow trickle and you have it idle for 40 minutes and that's what's primarily running the engine, or perhaps you have it run while you're on cruise control on a flat freeway.
The only risks I can think of are degrading the MAF sensor if it's in front of that (my first idea was to pour a little Techron right on a fresh air filter and let it evaporate as you drive) or, if it's low octane and you put your foot in it, engine knock. Thoughts? How bad is carbon buildup on higher mileage 3.5's?
02-05-2018, 09:59 PM
#3
A lot has been sorted since the early DI engines. A port injector is one solution, but it's not the only one.
I appreciate the spirit of your solutions, but to be frank, they are at best unwise and useless. ^^^p07 has it right, all bad.
I appreciate the spirit of your solutions, but to be frank, they are at best unwise and useless. ^^^p07 has it right, all bad.
02-05-2018, 09:59 PM
#4
While I understand where you are coming from with this idea, I can’t imagine any good coming from randomly shooting gas (in any amount) through the intake when it’s not designed that way. What I do recommend however is that every 50-75k miles you take it in to get the valves cleaned. The carbon build up is not immediate and takes some time to occur. So your little spritz of gas every 5000 miles really will not do anything for the car. Another option is to have a catch can installed, it’s very popular with the VW crowd and it does help a lot but it will not prevent carbon buildup completely (but it does cut down on it a lot).
I will also say that your concerns are not unfounded. I have seen numerous VW’s with the 2.0T engine for sale requiring new engines with owners citing bent valves as the cause. I also seen first hand an A4 that was literally shooting out bunches of black carbon bits from the exhaust everytime it was revved. I love the prospect of what DI has allowed companies to do, however it really isn’t ready to be the only system and Toyota is doing it properly.
02-06-2018, 10:45 AM
#6
Senior Moderator
Trending Topics
02-06-2018, 12:42 PM
#8
In terms of what is Honda/Acura doing to prevent this buildup, they are doing what everyone else is doing. That is letting you get through the warranty and then good luck thereafter. Toyota is currently the only manufacturer that I am aware of that is actually doing something so consumers don’t have issues down the line. Everybody else is using DI technology with the hopes you’ll get through the warranty and down the line they will suggest you get your valves cleaned as an extra $500 cost. So in reality while DI has allowed better performance and fuel economy (for the most part) it also puts more money into manufacturers pockets when you have to go in and get the valves cleaned every X miles. There is a trend in auto manufacturers towards making things harder for people to DIY at home and designing things so that only the dealer can fix it when it breaks. Though in this specific regard if you’re handy you could take the valve cover off and clean the valves yourself.
02-06-2018, 01:08 PM
#9
Latent car nut
iTrader: (2)
Join Date: Jan 2017
Location: Southern New Hampshire
Age: 68
Posts: 7,844
Received 2,005 Likes
on
1,407 Posts
Modern engines are designed to work via precise computer controlled air-fuel ratios. Spraying fuel into the intake at a random amount will throw this off. At best you’re hoping the computer will sense this and compensate for the sudden unexpected fuel increase and wost case scenario one cylinder gets too much fuel completely throwing off the fuel-air ratio preventing proper combustion leading to what is essentially called “flooding”. Though I do not expect flooding to occur if you’re only spraying small amounts in, unless you have precise control of the amount going in this is always a risk and getting precise control will not be easy. I do not feel the risk are worth the small benefits you’re seeking. Especially if you’re going to be spraying once every few thousand miles.
In terms of what is Honda/Acura doing to prevent this buildup, they are doing what everyone else is doing. That is letting you get through the warranty and then good luck thereafter. Toyota is currently the only manufacturer that I am aware of that is actually doing something so consumers don’t have issues down the line. Everybody else is using DI technology with the hopes you’ll get through the warranty and down the line they will suggest you get your valves cleaned as an extra $500 cost. So in reality while DI has allowed better performance and fuel economy (for the most part) it also puts more money into manufacturers pockets when you have to go in and get the valves cleaned every X miles. There is a trend in auto manufacturers towards making things harder for people to DIY at home and designing things so that only the dealer can fix it when it breaks. Though in this specific regard if you’re handy you could take the valve cover off and clean the valves yourself.
02-06-2018, 02:39 PM
#10
I think if you injected far enough upstream to allow evaporation and even distribution, the O2 sensor would dial back the injectors until you got a stoichiometric mixture. It's basically the same idea as methanol kits that people commonly bolt on to DI Turbo engines, but since we have no turbo we'd be doing it for cleaning purposes rather than mixture cooling/octane boosting.
02-06-2018, 02:42 PM
#11
Latent car nut
iTrader: (2)
Join Date: Jan 2017
Location: Southern New Hampshire
Age: 68
Posts: 7,844
Received 2,005 Likes
on
1,407 Posts
I think if you injected far enough upstream to allow evaporation and even distribution, the O2 sensor would dial back the injectors until you got a stoichiometric mixture. It's basically the same idea as methanol kits that people commonly bolt on to DI Turbo engines, but since we have no turbo we'd be doing it for cleaning purposes rather than mixture cooling/octane boosting.
Long story short, injecting fuel into the intake on an engine not so designed is a bad idea no matter how you cut it.
02-06-2018, 03:15 PM
#12
Burning Brakes
Maybe not the same thing, but somewhat related . . . . . . . I thought auto manufacturer learned a valuable lesson from Toyota/Lexus in the late '90's early '00's when they were being hammered for sludge. I am sure the issue is not totally eradicated, but is under control for the most part. Enough to not have to alter your vehicle. Plus wouldn't a mod like that just totally hose your warranty? I mean they could deny anything, not only issues from what you may have altered.
02-06-2018, 03:16 PM
#13
I think you can clean with vapor alone; that's how dry cleaners work.
You can also inject fuel into the intake on a DI engine not designed for that. I've a 335i and methanol injection is a common modification.
You can also inject fuel into the intake on a DI engine not designed for that. I've a 335i and methanol injection is a common modification.
The following users liked this post:
kirbman (01-25-2021)
02-06-2018, 03:34 PM
#14
Latent car nut
iTrader: (2)
Join Date: Jan 2017
Location: Southern New Hampshire
Age: 68
Posts: 7,844
Received 2,005 Likes
on
1,407 Posts
Please understand, the intake charge won't even be "vapor" by the time it reaches the intake valves. Why? Because all of the gasoline injected will be fully evaporated by the time the fuel reaches the intake valves. If you enrich the mixture to the point where fuel vapor reaches the valves, it will be way-WAY too rich for the fuel control system to compensate.
02-06-2018, 07:59 PM
#15
This is not exactly true, there is a thread around here somewhere which references at least two manufacturers of DI engines who are using two injectors per cylinder; the main one is the DI unit, the secondary injector is a port unit which sprays a very small amount of fuel on the back side of the intake valve. Personally I expect this to be the wave of the future.
Please understand, the intake charge won't even be "vapor" by the time it reaches the intake valves. Why? Because all of the gasoline injected will be fully evaporated by the time the fuel reaches the intake valves. If you enrich the mixture to the point where fuel vapor reaches the valves, it will be way-WAY too rich for the fuel control system to compensate.
02-06-2018, 09:56 PM
#16
I think some things I've read that the OEM's are doing is precise control of the injection event. A slight delay, after the valve closes or is almost closed helps a great deal. The other is very precise control of how and when the PCV system operates. It's technology that is still evolving but OEM's are figuring it out and the benefit to economy and performance is worth living with the ever decreasing downsides...its better than auto stop/start!
02-06-2018, 10:04 PM
#17
I think some things I've read that the OEM's are doing is precise control of the injection event. A slight delay, after the valve closes or is almost closed helps a great deal. The other is very precise control of how and when the PCV system operates. It's technology that is still evolving but OEM's are figuring it out and the benefit to economy and performance is worth living with the ever decreasing downsides...its better than auto stop/start!
Tell me about it, I despise stop start.
02-07-2018, 11:23 AM
#18
Please understand, the intake charge won't even be "vapor" by the time it reaches the intake valves. Why? Because all of the gasoline injected will be fully evaporated by the time the fuel reaches the intake valves. If you enrich the mixture to the point where fuel vapor reaches the valves, it will be way-WAY too rich for the fuel control system to compensate.
It'll only be too rich if your single injector is putting out more fuel than the six other injectors would be putting out under the same conditions.
Regarding precise timing to control deposits, that'd only be helpful in an Atkinson cycle engine, where the intake valve is held open momentarily during the compression stroke. Squirting a dab of fuel out would help keep the valves clean though.
02-07-2018, 11:26 AM
#19
I'm half-expecting to see pictures of a MDX with an engine fire.
02-07-2018, 11:29 AM
#20
Latent car nut
iTrader: (2)
Join Date: Jan 2017
Location: Southern New Hampshire
Age: 68
Posts: 7,844
Received 2,005 Likes
on
1,407 Posts
You said it won't be vapor by the time it gets to the intake valves, and then in the next sentence you said it will be vapor by the time it reaches the intake valves.
It'll only be too rich if your single injector is putting out more fuel than the six other injectors would be putting out under the same conditions.
Regarding precise timing to control deposits, that'd only be helpful in an Atkinson cycle engine, where the intake valve is held open momentarily during the compression stroke. Squirting a dab of fuel out would help keep the valves clean though.
It'll only be too rich if your single injector is putting out more fuel than the six other injectors would be putting out under the same conditions.
Regarding precise timing to control deposits, that'd only be helpful in an Atkinson cycle engine, where the intake valve is held open momentarily during the compression stroke. Squirting a dab of fuel out would help keep the valves clean though.
02-08-2018, 01:04 PM
#22
How'd that happen!?
Throttle body injection was used for decades. It's less precise, but I'm not advocating continuous use. Nothing will run lean because if there's excess O2 in the exhaust, it'll be detected, and running mildly rich is only harmful to fuel economy.
Throttle body injection was used for decades. It's less precise, but I'm not advocating continuous use. Nothing will run lean because if there's excess O2 in the exhaust, it'll be detected, and running mildly rich is only harmful to fuel economy.
02-08-2018, 01:19 PM
#23
Latent car nut
iTrader: (2)
Join Date: Jan 2017
Location: Southern New Hampshire
Age: 68
Posts: 7,844
Received 2,005 Likes
on
1,407 Posts
You can believe what you want, however, in reality, any DI engine not designed with additional port injectors (or an upstream injector) will run way too rich. Not only will fuel economy suffer, but so too will the exhaust emissions and the catalytic converters.
02-08-2018, 08:46 PM
#24
There have been a couple of MDX's that caught on fire while parked, this is one that was posted a while back.
Thread
Thread Starter
Forum
Replies
Last Post
mzilvar
Car Parts for Sale
33
09-10-2014 12:53 AM
P-TownTL35
2G TL Performance Parts & Modifications
4
11-22-2012 11:41 PM
akertulis
3G TL Performance Parts & Modifications
7
11-16-2010 11:33 PM
Excelerate
1G TSX Performance Parts & Modifications
1
12-06-2008 08:41 AM