Not Jobless
Mr Funbags
How hot does gasoline have to get before aeration occurs?
This is in a pressurized EFI system running about 36psi.
This is in a pressurized EFI system running about 36psi.
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Aeration
- Thread starter Not Jobless
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As in vapor locking? Im sure the higher fuel press requires more heat to vapor it. Im curious now since my fuel system is a bit close to the exhaust...
Glenn
Well-Known Member
That's true. Cooling system works on that principle.
Not Jobless
Mr Funbags
No, not vapor lock.
The point in which the fuel gets hot enough, under pressure, to create vapor in the lines and cause performance issues.
64FJ40
Well-Known Member
The problem is that gasoline isn't a homogeneous compound. It's got a bunch of different alkenes and alkanes and various hydrocarbons all mixed together. Each one of those different compounds has a diffferent vapor pressure. Some will volatilize at cooler temps, and others at higher temps.
No matter how cold it is (in real world situations), some of the liquid will become vapor, so there's no defined point where it 'happens'. It's just that, the warmer it is, the faster it happens. Keeping the system under pressure helps counter the effect, but I can't tell you how much for sure. 36psi is about 2.5atm (above the ambient atmospheric pressure of ~1), so I'd guess that the fuel under pressure is more resistant to vaporization by a factor of about 3.5 <--- WAGNER.
No matter how cold it is (in real world situations), some of the liquid will become vapor, so there's no defined point where it 'happens'. It's just that, the warmer it is, the faster it happens. Keeping the system under pressure helps counter the effect, but I can't tell you how much for sure. 36psi is about 2.5atm (above the ambient atmospheric pressure of ~1), so I'd guess that the fuel under pressure is more resistant to vaporization by a factor of about 3.5 <--- WAGNER.
Ashes
Well-Known Member
Altitude may play a small part in this too. Liquids boil at different temperatures at different altitudes.
jeepmauler
Well-Known Member
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I'm gonna say 210* on the guage and air temp 'bout 90* seems to send my shitbox into fits
but you already new that:flipoff:
Nuzzy
Well-Known Member
I'm gonna say 210* on the guage and air temp 'bout 90* seems to send my shitbox into fits
You act like you've just done some real world testing... :redneck:
Binder
Well-Known Member
You have no idea........
CrustyJeep
Well-Known Member
Vapor lock :flipoff:
I don't know what temp the fuel would have to reach to boil under 36 PSI, but we all know it's quite hot. I would never expect it to happen with the pump circulating fuel. I've only seen it happen after hot shutdown, and then only on a hot day.
CrustyJeep
Well-Known Member
Altitude is negated by a pressurized system, although hot shut down + high altitude + fuel system pressure drop could be a problem.
Binder
Well-Known Member
Less common on a circulating system but it still happens. The 5.0 does have a dead headed fuel rail (I checked) which contributes here too. We could probably do some testing with a thermocouple but in the end it just needs to be cooler.
CrustyJeep
Well-Known Member
What??? That can't be right...
Not Jobless
Mr Funbags
Huh?
All fuel pumped to the motor is returned to the tank via the pressure regulator and return line, minus of course what is burned.
CrustyJeep
Well-Known Member
Yeah, then I'd be really surprised if vapor is the problem, unless you're getting the classic hot restart problem.
Binder
Well-Known Member
Look at your fuel rail. The fuel goes into and out of it on the same spot. There's only like 2 inches that is through circulated. The end injectors are a dead givaway. There is no way the fuel is circulated past them.....
jeepmauler
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I was chatting with Conover today and he felt that the injectors were fubar.I did have probs with them right from the get go and alot of what he cited as examples/symptoms were spot on to what we were dealing with.Maybe it's time for 24# 'jectors and MAF:FIREdevil:
jeepmauler
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Brad started having issues towards the end of the week but my junk would barely run from the get go
F'in sucked!! so many possible causes to the symptoms presented that trouble shooting was a NIGHTMARE!! Seemed the root of the problem was heat affecting "X" and the whole shiteree took a dump Way more complex than that but thats the "jist".Rick and Brad got it runnin good enough to still alow me to destroy some ****:; :FIREdevil:
Binder
Well-Known Member
Could very well be.....It's definately heat sensitive, maybe your injectors are being effected by heat?<shrug>
If I had all of the answers it would have been running like a top last week......
