So the 78% humidity level was a figment of my imagination?
Read below, the fuel is heated in the fuel rail before returning to the tank via the fuel return line. Remember to help get rid of heat soak problems, and vapor locking the fuel system.. Oh and lest we forget the water you are going to pick up when you refill your tank at the local station. Every fuel storage tank has water in it, and if you get bad gas (ie fuel with a high percentage of water in it, and it has happened) due to a leak in the tank or just from the refining process alone, then it can and will build up in your tank if you fill up often enough.
It may not, but as you might know, most of the fuel systems these days, atleast on Fords, have recirc fuel systems (exception here is the NEW 3.5L which doesnt use a return). Meaning the fuel is pumped into the fuel rail, regulated to a certain pressure, and any excess is being pumped via a return line back to the tank, taking ANY heat the engine has to give off back with it.
Correction, it does NOT draw fresh air in. It only relieves pressure from the vapors into either the intake or the purge canister. (that is what the purge valve is for, why draw fresh air in, and loose the fuel that has evaporated, we want to keep that as much as possible.) That is what sets the CEL, is the low pressure in the system. I recently had an issue with my CEL coming on due to a muskrat chewing through my purge line on my tank. I taped it up and all was good, but it took the light almost 20min on the highway to come on, in 75*F weather. The reason you want higher pressure in the tank is because it requires a higher boiling point for liquids at higher pressures. Fuel ya know has a boiling point of 72*F at sea level. So ya heat the contents of the fuel tank up by recircing it from the engine, you pressurize the fuel in the tank (slightly less than 10psi), and then ya let it cool... Gives ya condensation.
And all the while the vehicle isnt running, there fore the purge system isnt operating, and that vapor will condense the next time you run your engine.
I forgot to add here. That the heat taken back to the tank on diesel engines is MUCH higher due to the fuel flowing through the HEAD and not just a fuel rail. If you check the temp of the fuel before you start a diesel, and after it has ran for 20min I bet on ANY tank you will notice atleast a 5*F difference in the temps due to the heat taken back to the tank. This also helps with anti-gelling during the winter months.
I also forgot to add that the water in a fuel tank will NOT evaporate in liquid form, because the fuel is lighter than water, therefore blocking air from evaporating the fuel. The water in the tank, unless its a hot day, will not boil, but it will condensate once the temp gets high enough in the tank. So more water can be added back to the tank from any air that might have been in there.
Nope. But you need to understand the difference between
-relative- humidity and the amount of moisture in the air.
Many late model vehicles (Ford included) use returnless fuel systems.
I always do. I also try to remember to turn off the coffee pot when I leave the house.
According to this then, keeping your fuel level above 1/4 tank (or whatever it is you're advocating) will result in MORE water in your fuel tank. According to this, the best solution is to not buy fuel, i.e., an EMPTY fuel tank.
Umm, no. Returnless fuel systems have become more prevalent over the last 12 model years.
Like hell it doesn't.
Never heard of the canister vent solenoid (CVS)? Do you actually think that purge can occur without allowing fresh air into the system? Like a said earlier, one would -think- that someone who worked for Fords' technical hot line would have a minimal understanding about how the EVAP systems actually worked. You may want to start with the diagnostics for codes P0455, P1450 and P1451.
There are lots of things that can malfunction that will illuminate the CEL.
Am I supposed to be surprised by this as you were? Did you ever look at the monitor criteria for the EVAP system?
This is just ridiculous.
What fuel has a boiling point of 72*F at sea level? Good god, it couldn't possibly be gasoline, and this site;
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much proves that you are in error.
Pressurize to 10 PSI? No way, no how.
10 inches of water would be more like it. Pressurize to 10 PSI and you'd be popping all sorts of grommets and unclamped vapor hoses.
Condensation from where? You just got done (erroneously) explaining how the system is not vented and is pressurized to 10 PSI. Half of what you say contradicts the other half.
But you earlier claimed that it was the heated fuel from the running engine that caused the condensation. Half of what you say contradicts the other half.
No this was used as an example of WHERE the water would come from. And it is completely possible for this to happen. I have seen it with my own two eyes. Havent you? You work at a dealership..
Not on Fords, what dealership did you say you worked at? Cause EVERY fuel system on a Ford EFI engine that I have seen in about that time span, has used a LOOP system that continuously returns fuel to the tank while the ignition is on. Here is link so you can update your knowledge into the next century. Enjoy.
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Watch out, its a PDF document, you need Adobe reader to view it. Oh and this does come with pictures for you. By the way, this only emphasizes what I have said about the fuel return, and what I have been taught through the years.>
You might want to look at this diagram on the second page. As explained the VMV is mainly used for TESTING purposes only. To check for leaks somewhere in the range of .020"-.040".
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And who said I was suprised by this? Although I figured if it was going to come on, then it would have done so at start up, not while driving down the highway..
Well according to this site, which lists the boiling point of gasoline as
40*-200*C makes me right, because 40x1.8= 72*F. Unless you have a better calculator than I do? You might want to read around before you start knocking down peoples information.
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by this chart you will notice the boiling point of Kerosene which is used to make diesel fuel has a starting boiling point lower than the highest boiling point of gasoline, so in the refining process I would take anything that boiled over 100*C and use it in diesel fuel, not gasoline.
Ok I was wrong on the exact pressure, its actually about 6-10"H2O which is about .25-2.8psi as described here
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Which means in hot weather your fuel tank does have some pressure on it. I did notice in one article that it stated something about a vacuum release valve in the fuel cap, but that it was used in case the VMV or "canister purge valve" gets stuck and vacuum exceeds test specifications.
I dont know how you can say that. Maybe in your mind, or maybe I didnt explain it clear enough.
skimmer: 40C = 72F ? Are you out of your mind? This is just our point FT. Get it right, or shut up. And please don't ask forgiveness for making a typo. That is also the point. If you can't type it in and be correct....stay out.
You reposted that whole post just to add that.. Now THAT was funny. So just curious, which part of that was funny? The part that I was right, or the part that he had other info?
Hold on a minute, if the water comes from leaking underground storage tanks, why are you claiming that it comes from running your fuel level too low? Or are you saying that one should keep their fuel above a certain level to dilute the water that is going to be pumped in unavoidably from underground storage?
You've seen what with your own two eyes, water laying in the bottom of a storage tank being sucked up by the delivery pump and then being dispensed into a fuel tank?
Nope. i will not/have not ever hung around the insides of a fuel storage tank watching water get pulled up the pipes to the pump(s), and if I had, I'd have said something to the person dispensing the fuel.
What I'm saying is that you really have no way of knowing where the water contamination came from. For all you know, it was caused by cross contamination by the bulk carrier that delivered that load of fuel and as a reminder, non of this in any way supports your assertion that not keeping your fuel tank above a certain level is going to result in disabling amounts of water in a fuel tank.
I -have- worked at dealerships, but last time I checked, slavery was abolished sometime right after the civil war.
Yes on Fords.
How far back do you want me to go? (the 70s?) Can I include the major metropolitan natural gas utility fleet where when hired, I was the #1 pick over 375 applicants? How about the major diagnostic equipment manufacturer where I was the regional training manager? How about the state IM-240 program where I was the senior referee overseeing 8 test stations with a total of 44 test lanes, 2 diagnostic centers, chaired the ad hoc steering committee, hosted numerous visiting officials from other states /countries, hosted in service days for just about every tech school instructor in the state/ fuel and ignition manufacturers from across the country, technician outreach, etc, etc, etc...
While the ignition is on? Maybe for two or three seconds when the key is first turned on but rest assured, even from the earliest days of EEC IV, for the fuel pump to continue running, there HAD to be a RPM input to the PCM before the fuel pump would be energized via the fuel pump relay. You want a lesson on repair and overhaul of VV carburetors too since we're covering really old BASIC stuff here?
Well junior, I know a Windsor block when I see one, so my guess is this is some backyard ~expert~ modding an EEC-IV system probably from the late 80s or early 90s. hell, the Windsor hasn't been used in a Mustang since 1995...Puh-leeze... This is shit I was fixing two decades ago, in the dealership where I usually had 40 hours booked before lunch on any Wednesday.
Well then, you are seriously out of date and in no position to be handing out your supposed truths about how anything built in the last dozen years works. If this represents the state of your knowledge, all I can say is find a different career because you have WAY to much catching up to do. In the mean time, chew on this a bit;
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DO note where they say; "Returnless systems are found on many late model cars and trucks. The first ones appeared back in 1993 on certain Chrysler V6 and V8 truck engines. By 1998, all Chrysler cars and light trucks had them. In 1996, Toyota introduced its first returnless system, followed by General Motors and Ford in 1999. Honda went "returnless" in 2001, and today you'll find returnless fuel injection systems on almost all new vehicles."
Okay, you've now proved that you don't know the difference between a vacuum management valve and a canister vent, even though the latter is shown in your above referenced article (it's the yellow thingy in the lower right corner in the diagram on page 17). Now be a good lad and follow the yellow arrows and note where they originate where it says "from atmosphere" and tell me how this in any way is different from what I've already described.
Is finding an ACCURATE temperature conversion such a major task for you? I don't know where you got that conversion formula, my guess is you either purposely ignored the "add 32*" part hoping to not get caught, or you're just plain sloppy.
40 degrees Celsius equals 104 degrees fahrenheit. No 'ifs, ands or buts.
Ya know, at this point, if you told me the sky was blue, I wouldn't believe you.
You've been wrong about a lot of things. You definitely also need to work on your pressure conversions because there is no way in hell that 10 inches of water equals anywhere near 2.8 PSI. (hint: 1 PSI= 2 inches of mercury=27.6 inches of water)
Oh, just so you know, the guy that wrote that article (John Thornton), we've been friends for quite a few years... Now find me one from Bill Fulton and I'll tell you how long I've known him also.
It may, or it may not. Why don't you go back and actually read the article that ~you~ cited and try to understand when it might and when it might not.
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You worked Fords' tech line and you're first discovering this from a magazine article?
Please don't explain anything to me (or anyone else). I have way more years of experience than you (like 27 years more), way more training, way more certifications and way more dedication to the trade.
Oops I forgot to add the 32 on top of that.. LOL I just did the multiplication.. But hey everyone is entitled to make a mistake... Atleast I admit mine.
Skimmer I suggest if you dont have anything useful to add to this forum, other than bashing on other people, that you not reply.. I do appreciate you pointing out that error though. Thanks.
Only reason I replied to this thread is because it was a DIESEL question, unless someone can refute my knowledge about diesels, can we just drop this and agree that you shouldn't run the tank down to the "low fuel light". We seem to have gotten off the subject on this thread, surprise.. LOL
Fuel is circulated through the head on the International (Ford) 7.3 and 6.0L diesels, and this carries quite a bit of heat back to the tank. Therefore, allowing your tank to get down to about 5 gal allows the fuel to warm up quickly. This will cause a more rapid depletion in the additives of the fuel, and possible over heating (gumming) of the fuel pump. Thanks to the addition of parrafin wax (used to help lubricate the upper cylinder area).
If water wasnt present in fuel (diesel is more prone than gas) then all diesel engine manufacturers wouldnt have need to install fuel/water serparators. Running the fuel down to a minimum level pretty much assures that you will pick up the water in the bottom of the tank, where as otherwise it might not happen as much.
LOL is right. You cited a reference to an outdated gasoline engine to try and prove a point.
Which additives? Why don't these additives deplete at the nozzle where it's even hotter?
"gumming" is not "overheating." Ever hear someone say that their overheating vehicle was "gumming?"
Addition?
Thing is, the water separators are not there because people run their fuel levels low. I've worked two fleets where the diesel trucks were seldom run below 1/2 tank, the trucks were refueled after every shift yet the water separators still caught water, and no, the storage tanks were not leaking. I have also made cross country trips in 1 ton Ford diesels towing a 40 foot 5th wheel enclosed car hauler with two cars inside where we consistently ran the fuel down to one gallon or less left in the tank with absolutely no ill effects.
As someone referenced in an earlier post; Ever try driving with a coffee cup in the cup holder without a lid? Are you going to argue that it doesn't slosh and spill? Does it occur to you that the fuel in the tank is doing the exact same thing? Ever hear of a fuel gauge slosh module?
First one I can think of off the top of my head is Cetane, ya know to help speed up the burn of the fuel in the cylinder. Which is just the opposite of Octane, which is used to slow the burn of gasoline in the cylinder to better control the burn. Most diesel runs a cetane of about 43, but can vary usually between 30-60 for highway grade diesel fuel.
Because at that point in time we dont care. They are being injected into the cylinder and we want them to atomize, and they are already trapped in a closed enviroment (the combustion chamber), so even if it evaporates, it wont be lost just vaporized. The fuel doesnt sit at the very tip of the nozzle, it held behind a poppet valve, and usually requires about 2,700psi (but can be as high as 5,000psi depending on the system), to lift the poppet and expose the fuel to the nozzle end of the injector.
NO but gumming can lead to overheating as it coats surfaces, and doesnt allow for heat transfer as effectively.
Nope, but i have heard of sludge buildup and tarnishing of an engine. Have you ever let a weed eater set in the garage over the winter with fuel in it that has been there since late July? If you have then you have seen this gumming effect for yourself. I have seen filters on weedeaters so plugged that they have to be replaced and the carbs dismantled and cleaned. That is why you dont want to let fuel sit and allow the additives to evaporate. The warmer the fuel is, the faster the evaporation.
Yes there is already some in diesel fuel, but more is added to allow for proper lubrication of the upper cylinder areas. As well as, lubrication of the injectors.
I thought since you broke up the original post, that I would point out at this point I was discussing how to MINIMIZE the amount of water collected in the fuel/water separator.
NOTE: When I capitalize I am not shouting, I am stressing the word. Please do not misconstrue this.
Just curious, how long did you drive that truck after you did that? Because I can almost guarantee that the fuel in the tank at that level was over
100*F, ya know since CHT runs about 200*F and that fuel being returned to the tank had to be atleast 150*F. Depending on ambient temperature the amount of heat dissipated through the tank could be more or less.
I have!! Lets all act shocked now! The only reason for the slosh module is to keep the fuel guage from "bouncing" as the fuel level gets lower in the tank, by averaging the fuel readings over a certain time period. This can also lead to innaccurate fuel readings, and from what I can make of that, you are helping my argument with that statement. The reason I say that is because if your guage is reading just above E, then more than likely, you have less fuel in your tank than that. Especially if you take alot of corners, or drive down very rough roads. Also, the reason for slosh modules is becuase alot of manufacturers took the baffles out of fuel tanks in an effort to reduce manufacturing costs and increase productivity. Someone somewhere decided that an electronic "baffle" was more time effective, thus cheaper, than actually designing baffles into fuel tanks anymore. If you doubt me on this, read this page. Look at Regulations for vehicles less than
10,000 GVW answer #2.
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Might I add that the slosh module has nothing to do with how the fuel acts in the tank. It only effects how the information that the sender gives is interpretted, and thus displayed via the fuel guage.
Umm.. You seem to be describing Cetane both as a hydrocarbon chain -and- as a rating number, which means that you're just regurgitating words from memory without any thought to what is relevant or appropriate.
We don't? Why wouldn't we care about what the heated fuel might do to the nozzles while it is waiting for the nozzle to open. If it's going to gum up the fuel pump, certainly it would gum up the nozzle...
What about the fuel in the rail -at- the nozzle soaking up heat like what would happen at a hot shut down. If heat causes the fuel to change properties and gum up a fuel pump, certainly this can happen at the much hotter (relatively) fuel nozzle.
And we're also to believe that these physical changes only occur at ambient pressure and will not happen at pressures between
2700 PSI and 5000 PSI in close proximity to the cylinder head.
Well, which is it?
You have a diesel powered weed eater?
Me thinks you are talking about gasoline and gasoline engines.
They add paraffin wax to diesel fuel do they? Sounds very counter productive.
But, but, but... there is huge amounts of water in diesel fuel to begin with, your cautions seem to amount to a fart in a wind storm.
I can't give an exact mileage, I know that it has gone over
100,000 in the 2+ years since I shared to co-driving.
Do you know what the temperature ranges are in Iraq, Nevada, Arizona, etc.... the temperatures ranges that you are warning about exist as ambient in inhabited places of the world where diesels are very common. How about a tank farm in Texas during summer, do you think the tanks of diesel fuel won't go above
100*F sitting there baking in the Texas sun?
You (as usual) miss the point entirely. If slosh modules are needed to accurize fuel gauge readings it's because the fuel in the tank is being violently sloshed when the vehicle is driven making your point about picking up water from the bottom of the tank meaningless because NOTHING segregates itself to the bottom of the tank to begin with DUE TO the sloshing that naturally occurs while the vehicle is in motion.
OK, what about the Cetane ratings dont you understand? The higher the number the faster the diesel burns, which means the higher the Cetane content in the fuel. I never said it was a hydrocarbon, personally I dont care what the formulation for Cetane is. I know what it does and why it is there, and I dont need to know anymore than that.
As I stated below the fuel is only stationary in the injector long enough for the injection event to take place, otherwise any leftover fuel drains and the rail is open to free flow around the injector.. So we are talking a matter of milliseconds that the fuel is stationary in the injector..
You are starting to show that you dont know how the HEUI system works. Because as soon as injection stops, the remaining fuel (if any) is open to drain. It doesnt hold the fuel in the injector. Once the fuel is in the rail, its in a enclosed space and pressurized, so at this point the fuel shouldn't separate or evaporate. That is why I keep talking about the fuel tank.
WHAT?? Now you are putting words in to my mouth. Did I not just say that we want the fuel to atomize during injection into the cylinder?? Because I thought I did. Not to mention your statement would go back to the beginning of my post here about not caring if the fuel changes its state during injection, because we want it to.
Again someone with a minimal amount of common sense would realize that the (gumming) would refer back to what was causing the overheating.
I am not even goin to justify that amount of insanity.
I have seen it happen in diesels as well. Just like gasoline, diesel fuel contains an "additive package", and in that package is all kinds of things, some of which is detergents to help clean the system. The longer the fuel sits the more the package depletes. It also happens the same way when you heat the diesel fuel. The hotter the fuel gets the quicker the "package" is depleted.
Why do you think they have to add anti-geling agents to diesel fuel in cold weather? Its to help keep the paraffin wax suspended in the fuel, and not solidifying.
I dont know if you noticed, but I did correct myself. I already stated that I forgot to add the 32 after doing the multiplication. But then again I guess you dont care about that! All you care about is running people down on here, and trying to make you look like your SH** dont stink. Well yer wrong my friend, everyone's stinks at some point in time. Atleast I admit my mistakes.
Apparently a lot less than you. Cetane is a hydrocarbon chain molecule formally known as Hexadecane, it has a cetane rating of 100 and as such, is used as a benchmark much the same as octane is used for gasoline. Point being is; you cited cetane as an -additive- that would be "rapidly depleted" if and when diesel fuel were warmed above some imagined temperature. Thing is, Cetane is not necessarily a component of diesel fuel to begin with, it is simply a hydrocarbon that ignites rather easily and is used as a reference to a scale.
Prove that Cetane is a component of diesel fuel, I will be happy to show that other compoinds are used to adjust the cetane rating of diesel fuel.
Because you didn't know, and you don't know.
How can you know that something is there and why it's there when you totally misuse the word to begin with?
Horse shit. What happens when a hot engine is shut off? Where does the fuel go? Are you claiming that Ford P$Ds magically evacuate all fuel from the rail?
You can't think past the end of your nose. Shut of a hot engine and the fuel is there to cook, the fuel temperature will increase due to heat soak and it will increase above those "the sky is falling" temperatures you keep claiming.
Where is the rail? Is it outside the engine compartment? Maybe it's inside the HVAC where the A/C can blow cold air on it. Any other fantasies you'd care to share?
No, you are tripping on yours.
Again, what is so different about a temperature rise in the fuel tank that will cause rapid depletion of additives that somehow doesn't exist/occur on top of the engine in the fuel plumbing?
Your first statement was that heating was gumming. Your second statement was that gumming can lead to overheating. Got a third whopper? (did I just spell 'backpedal' w-h-o-p-p-e-r?) Why doesn't this gumming and overheating happen in a standard run of the mill Stanadyne mechanical injection pump that is engine mounted and subject to a lot more heat than the 100* you claim will cause such problems?
You brought it up.
Oh, so you -were- talking about gasoline and gasoline engines. Weren't you just complaining that this was strictly a diesel discussion?
Ah, yes... here we go with additives again , and heating the fuel (even though it's been done for about 100 years).
Well gee, if they didn't "add" the paraffin wax to begin with, they wouldn't need to add anti-jelling agents to counter act it. Hmmm... I see a conspiracy. Or, maybe they -don't- ADD paraffin, maybe it happens to occur naturally as part of the HC chain.
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