Snake Oil? Proprietary Throttle Body Cleaners and Tranny Flushes? (like BG)

now what about that 1 performance tweak you mentioned earlier. pressing a pin in the vacuum port of the FPR to max fuel pressure at all times. doesn't that conflict with the mechanics about an atmospheric controlled FPR? doesn't pushing on the diaphragm decrease pressure?

wait I think I just figured it out. let me know.

Ok so, noahpetes image.



here's the reason I was so confused. it was because I was assuming the FPR was on the DELIVERY side of the fuel rails. and then when more vacuum was present (assumingly at high RPMs) the regulator opened up more, allowing more fuel to pass to the injectors. and with less vacuum, it would close the valve, preventing fuel from entering the fuel rail.

this is not the case because our FPRs are on the return side of the fuel rail, and you WANT it to be closed. that way the back pressure in the fuel rails and everything before the FPR will be at it's set PSI relevant to atmospheric pressure, the spring load in side the FPR, and that's it!

fuel delivery was never an issue, nor was it the purpose of a fuel pressure regulator like I assumed. this is what was driving me to ask those earlier semi stupid questions. and is also probably what @Caligula was assuming.

 

My ears are burning and im running out of popcorn...

Heres the thing, one thing that DP did state that is correct, is that the point of port on the intake tract that the FPR is connected to will not have anything near full vacuum as is measured at the throttle plate. There IS vacuum, and there IS restriction within the intake. You CANNOT state that there is atmospheric pressure inside an intake tract. If you did, then like i said, vacuum leaks would not exist, and the MAF sensors would function like an appendix.

Also i already knew the FPR was on the return side. Most every fuel rail is designed this way. The removal or application of vacuum (depending on setup) restricts the return flow to increase rail pressure (or maintain it as demand will be higher in that instance).

Let me throw in there that CARB would never allow a car into California with any device that had a 'vent to atmosphere' or atmospheric pressure as this has been described here. CARB is the reason we have all this oil vapor shit being recirculated back into out intakes from the PCV and gunking up @CodeSeven 's throttle plate (to bring this thread full circle).

Let me also add that if you do a Google image search for the image you posted form the other thread, with the FPR illustration venting to atmosphere, it does not show up anywhere on the internet other than the thread here on Tacomaworld that DP linked to us. Just sayin......

What DP said was that there is no USABLE vacuum at that point in the intake tract. The question that we must ask is what are we defining as usable vacuum and what is the baseline vacuum measurement for the device running on that vacuum source? Atmospheric pressure does affect the outside air density of the available intake air BEFORE it enters the first restriction in the fuel control system, the air filter (or air box). The moment it enters this space, it is part of the internal combustion system. If you read some German repair manuals, it refers to the area from the airbox to the throttle body as the air/fuel preparation system not the intake. The restriction of the intake tract and the pressure differential created by the pistons moving are two functions of what creates vacuum in the intake tract, completely unaffected by atmospheric pressure from the point of the air box. The distance from the beginning of the restriction to the source is directly proportionate to the pressure differential that will be created at that point. The same way you can take a straw of a set diameter, suck on one that is 1 inch long, then the same one that is 12 inch long, the force required to pull a measure of air will be the same, but the force necessary pull the entire volume inside the 12in straw will be increased based on the total increase in volume and drag from inside the straw, or intake. This is why big ass intakes do not necessarily mean more power, as the same sized engine still pulls the same volume of air.

That being said, we already understand the Venturi effect that this intake will maintain about the same volumetric flow as long the the relative altitude of the intake and the diameter doesnt change. Though if it widens, the flow will slow, if it restricts, the flow will accelerate. For fun lets throw in Bernoulli's Principal that faster airflow moving over a fixed object will create a lower pressure zone. Inversely, an area where airflow is slowed or stagnated will relatively have a higher pressure than the area with faster flow. The basic concept of lift.

I also want to add the function of the 'resonators' as we have been calling them. They work as a result of wave harmonics to contain the resulting pressure waves that are formed from air being slammed against closing valves on the intake tract. They contain these harmonics as to prevent them from excessively slowing the high speed flow of air. If a mass of air slows, it must increase in pressure if it is unable to continue at the same speed into a new space. The intake manifold on any car is also a resonator, where instead of containing the rouge harmonics, as in a helmholtz resonator, it directs them into the adjoining intake runners. Part of Newtons Law states that the air mass will be affected by gravity, causing the slower moving, denser airmass to downwash into the resonators.

Now lets look at the intake tract on our tacoma. Imagine a one cubic inch mass of air on its journey into the engine shaped like a smiley face --->


1. First entry and restriction. Also largest volume segment of the intake. will be pulled in though the air filter, into the high volume, low speed, low density segment.

2. The intake runner, including the MAF. The air mass is at "atmospheric pressure" until it enters this restriction causing the first pressure change by accelerating the in order to maintain the same mass it is replacing as it enters the combustion chamber. According to Bernoulli's principal, this action creates a lower pressure area inside the intake runner. The pressure differential will vary depending on how much volume is entering the combustion chamber, which in turn will require air mass from upstream to replace it. The intake harmonics will create waveforms moving both back and forth through the manifold and the intake tract from the valvetrain as well as the throttle butterfly and IAC valve.

3. Here is that freakin resonator that the FPR hooks into. To take advantage of Newtons law, these attach to the bottom of the intake. Naturally higher pressure will accumulate into these areas as the harmonics from the intake track fill these voids.

4. The throttle body/IAC. This is The Narrow Sea between Westros and Essos. At WOT, the two sections operate as one, with the harmonics generated by the drivetrain extending into the intake tract. Likewise the pressure differential will be more significant coming form the engine at WOT, and proportionally less as the throttle closes. The IAC also generates these same effects but to a much lesser degree.

Here is the key. Air is continuously drawn in regardless of throttle position in order to keep the engine running. Harmonics do not increase in intensity with RPM, only with frequency. So throughout the entire tract, there IS VACUUM, as there is contained high speed movement of air within a space of reducing volume.

The point the the FPR connects will have a higher pressure related to the area outside of the resonator according to Bernoulli's Principal and Newtons Law. The air mass inside of this space will move in and out at a higher frequency in proportion to RPM, but everything that happens will take place as a secondary result of what happens to the air mass rushing towards the combustion chamber, subject to drag, venturi effect, and wave harmonics. You can see this with a vacuum gauge hooked up to the resonators. It will wiggle like you timing is slightly off from the harmonics, but it will definitely be in negative pressure.

Whats been created in this space that the FPR is reading is a new "baseline pressure" not based on whats is outside the engine, but the conditions created by the engine. It will be lower from atmospheric pressure by a few psi, but will allow a baseline for the FPR that does not rely on what altitude you are at for proper function. It will be based on air mass intake the intake.

At higher altitude, you loose horsepower because the engine has to run faster to pull in the same amount of air, and in turn use less fuel per cycle to match the lower O2 content. The vacuum draw on the FPR will stay relative to the vacuum draw at sea level as the same process that i described above will take place and drop the pressure in a similar manner.

 

And quit sticking your fingers in places.

 

Excuse my typos. Hard to type on my phone.

the resonator deal. in your pic you forgot to label one of the other air intake boot parts (your 4 cyl may not have it). This is what i truly believe is the real resonator. Its a small elbo or hook shaped tube on the back bottom side of the air intake boot just where it curves (or at least there's one on my v6). i've only been calling the one up front a resonator because of the lack of better terminology. lets just call it the atmoapheric chamber

And yes, vacuum leaks do occur. But only involving the ports and hoses that are connected after the therttle body where high vacuum is involved. Like the brake booster and a lot of the emission connections going to the cannister (?) above the front left tire in the motor bay.

and yes there can be a vacuum leak before the throttle body, it just takes a tennis ball sized crack in the intake to make a difference. Like when the boot gets too old and cracks, or a rat makes a homestead, or a bat somehow lodges himself in the throttle body flap.....

And like i mentioned in my previous post. After i cleaned my TB, i removed the fpr hose to get a clamp on while the motor was running. My motor wasn't phased at all. I didn't even hear a slight sucking noise as though there was any air draw. I thought that was really weird. But the only way well find out if theres any vacuum is by putting a gauge to that port. There will probably be 1 mmhg of vacuum in there. Maybe my machinist has a gauge laying around not connected to one of the machines.

This is probably how the fpr is able to vent without being affected by the pre tb intake vacuum. And yes, there can be atmoapheric preasure in that box. its not like the air in there remembers how things used to be and wants to stixk to the old ways. It will change depensing on altituse. Plus that the spring is compensating for that slight vacuum pull.

Im surprised you don't agree on the fpr having higher psi without vacuum, and less with. Especially knowing that its on the tail end of the rail. The only thing thsts happening when the fpr has vacuum is it opens the valve and releases the preasure by allowing the fuel to flow through. Remember, the fpr being closed is the only thing alllowing the fuel pump to build pressure in the rails. Otherwise the fuel would be free flowing at low to no pressure.

 

Yea not too sure, but the intake design is fairly similar between the two. They serve the same function regardless. If you look at the intake tract in the picture, there is another triangular resonator on the 3rz intake, right after the MAF. I was trying to focus on the section that the FPR plugs into. Im looking at a pic of a 5vz engine, and all I see is the large box in frot of the intake tube. Maybe i just cant see it form the pics im seeing.

Major vacuum leaks occur between the throttle and engine, but minor ones can be just and impactful. We were just discussing this in the other thread where the guy with the Ultragauge and Lambda readings. His MAF was underreporting what was entering into the intake, effectively the same result as a small crack in the intake boot. The reason those resonators or chambers are even more important farther up on the intake as that having harmonic waves affecting the airflow at the MAF will dramatically affect its function.

Remember the sensor in the MAF is a film or wire that uses the flow of air, not density, to change the temperature of the heated element. It doesn't measure an absolute temperature, it measure the amount of voltage drop from its voltage at idle. Any deviation from that point forward will most definitely affect your engine management, its just a question to what degree it will happen. The design of the airbox and intake tract, including the chambers and resonators, play a major role in this.

OK, that term the way you are using it, atmospheric pressure. I think the way its being used is the major issue here, especially with the disagreement im having with Dirtypool and the way he is using it.

Atmospheric pressure is not a single set number. It is a abstract noun that describes the mass of atmosphere being affected by gravity and other forces of nature at your location. Me driving my truck up on the curb, even though i only raised it 4 inches, caused the atmospheric pressure entering the intake to change, as well the atmospheric pressure on the tires, on the roof, etc etc. We discuss the concept of stoichiometry, and the 14.7:1 ratio for ideal (not perfect, but ideal) combustion based on 14.7psi. This is stated as ideal settings as even pressure at sea level can fluctuate at sea level based on tides and weather.

That pressure, whatever number it may be, should not be described as atmospheric pressure, because it is not. It is totally a creation of the vacuum created by the engine and the harmonics of the intake.

It totally depends on the design of the FPR. Adding vacuum could close the diaphragm, increasing pressure, or pull it open, dropping pressure. Just as removing a constant vacuum (as in idle manifold vacuum) could do one or the other. Most modern common fuel rails will have a FPR on the return side like ours, though where the vacuum line is hooked up will determine its function. For example, a FPR can be on the ported side of the throttle, so that its normally open, when the throttle snaps open, the ported vacuum pulls the diaphragm shut, then the flow of fuel holds it open until the throttle comes back down. Again the terminology is very important. You are never trying to increase fuel pressure, the purpose of closing the FPR diaphragm is to maintain pressure as demand by the injectors increase (from more frequent cycling, that is proportionate to RPM).

What ive been arguing is that the "vacuum sensing port" was NOT an oversight by Toyota. The 1VZ, 2VZ, and 3VZ engines have only and always been used in pickups like the Hiluxs, 4runners, and Tacomas until they were discontinued. Ive tried to find pics of other setups on these trucks for the fuel rail or FPR, but they are all the same. Toyota did not just make 'an oversight', as Dirtypool stated, for over 20 years in their literature. Of course the FPR is not being shut open or closed completely by the minimal vacuum in the intake resonator. Though it is being influenced by it, and the pressure being drawn is making a fine adjustment to the overall fuel pressure in the system.

Ok, im going to sleep now.

 

Now there is some real vacuum.
The FSM maintains that there is enough vacuum on the FPR at idle to lower fuel by pressure a nominal 6psi. There is not, call it what you want.

 

I'll call it vacuum.

 

The FSM is incorrect in this description. As you describe, the FPR , in this case is used for altitude compensation



Code, a 2000 Tacoma uses the fuel pressure regulator to maintain a constant fuel pressure relative to ambient pressure. The fuel pressure regulator port is simply for altitude compensation. Like the pool says, the point of location on the intake (pre-throttle plate) sees no measurable pressure change with throttle angle/engine load when compared to ambient pressure.

 

this is the newest vehicle I've ever owned. I have yet to actually look at the engine and think about how everything works. As a matter of fact I'm still trying to figure out how everything works on it. If nothing but air goes through the throttle body what is it that causes it to get so filthy then? I've seen some pics of a few that were taken apart and they were nasty. They looked pretty "carboned" up. If nothing but air goes through it then where is the black crap coming from?

 

Well now that I know this I'll be pulling the throttle body off and cleaning it. Thanks for pointing all this out. I do have a rough idle at times. It used to be just the typical 4 cylinder gentle rocking rough idle but it's gotten rougher over the last 20,000 miles.

 

Caligula has a picture posted above. If you look at his painted in #4 line, there is a hose connected to the valve cover and enters the throttle body about 2" before the throttle plate. This is a crankcase vent, not PCV as it enters before the throttle plate. Meant to capture blow-by gasses it contains contaminates oil/fuel vapors that can/do leave deposits.

 

Thanks for the info. Now I understand why the TB can get filled up with garbage. I'll be taking this stuff apart in the near future to inspect and clean.

 

They are both PCV's, they may not carry the name but they both function as PCVs. One is connected to manifold vacuum, and the one before the throttle in connected to ported vacuum.

The pre throttle one is what causes all the shit here:


The post throttle one is what causes all the shit here: