Re: In-the-tank fuel pumps cause death and destruction

I thought I could find a flow table with a quick search, but no luck yet. I think you'll find that even a 1/4" tube will flow a lot more gasoline that you might guess. 19 gallons in 30 minutes is only 0.63 GPM, and that is really a very low flow rate given any pressure at all.

Matt

Reply to
Matt Whiting
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Your correct, water does not mix in either. Diesel does not evaporate like gasoline which is the physical difference I was referring, and the fuel systems are not required by law to have an closed evaporative system like gasoline tanks have. Because of this most if not all diesel tanks are exposed to large amounts of outside atmosphere which contains water which condenses in the tank.

Reply to
Thomas Moats

I had to go to a Ford Exporer assy. plant one time when we shipped bad fuel pump product that made it all the way into the assembly line. The Ford guy who was dropping the tanks and swapping out the bad pumps with the Explorers up on a lift was smoking a cigarette the whole time. Gasoline was all over the floor, and the old sender units, dripping with gasoline, were being stacked into cardboard boxes that quickly became totally saturated in fuel to the side of the lift. I was simultaneously shocked and amazed.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Reply to
Bill Putney

Maybe if it's the sending unit that is not working?? Or maybe the tank itself that needs replaced??

I'm not always in a hurry to do a job. If it works out, sometimes I'll start draining the tank on one vehicle while I'm finishing up another job. It does cut into my bullshit time but I make more money.

Denny

Reply to
Denny

Are you suggesting buying a 3rd pump so that you can drain the tank to eventually install the 2nd pump???

Reply to
Al Smith

Hey hey hey! One question at a time! 8^)

Actually, the commutation (brushes) are in the fuel that is flowing thru the pump. The motor armature, magnets, pumping elements, and commutator are in the same compartment swimmimg/spinning in the fuel.

Nope. The "bearings" in the ones I worked with (supplied to GM and Ford) were simply holes molded into the plastic end caps of the motors - again - in fuel. That is typical of the modern automotive fuel pump. One reason fuel pumps can become noisy is that those plastic bushings wear (actually, usually the metal shafts wear a lot faster than the plastic due to abrassive glass fibers in the plastic) and the armature starts rattling around.

No - but there are brushes.

Magnetic drives are a great way of eliminating rotating seals, but that magnetic drive wouldn't transmit the torque needed to develop 60-90 psi. 8^)

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Reply to
Bill Putney

Sometimes that has a lot to do with the type of pump. For example, the roller vane type pump is inherently noisy. Often it would be the design of chioce for technical reasons, but the vehicle manufacturer will go with a different type for that reason alone. GM uses roller vanes but very sparingly because of noise.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Reply to
Bill Putney

Well, Thomas, we're arguing from what we've done and what's worked. You, on the other hand, are insisting that it couldn't possibly work. Difference is, we've done it and it has worked.

Reply to
Daniel J. Stern

That was cold! 8^)

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Reply to
Bill Putney

They learned that from the Japanese. I know Subaru and Mazda have been that way for years (and someone else posted Toyota too). I think it is unusual for an "American" car - but good to see thay're wising up.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Reply to
Bill Putney

Well lets do the math. As I stated in a another post it takes about 7 minutes to fill a 2 gallon can from the schrader valve on my car. That is 3.5 minutes per 1 gallon with a stock OEM pump. 3.5 minutes x 19 gallons is 66.5 minutes. The pump in my Crown Vic is rated at 21 GPH. It delivers out the schrader valve at just under 19 GPH. That is why I say bull-shit to the claim of pumping out 19 gallons or 72 liters in half an hour. It can not be done with a stock pump in the tank, and it cant be done with a transfer pump pulling the fuel out the schrader valve. That is especially true if the pump in the tank does not work, it will provide too much resistance to the flow and most likely cause the plastic fuel lines to collapse.

Reply to
Thomas Moats

The claim was to be able to pump out 19 gallons in 1/2 hour through the fuel pressure port on the fuel rail. It can not be done. The pump on a Crown vic is rated at 20GPH. To make the claim true you would need to at least double the GPH and take away the normal restrictions of the fuel system. I did not say you can not pump fuel from the pressure port, I do it on a regularly. I'll say it again, it takes on average 7 minutes to fill a 2 gallon fuel container. Do the math. The claim is bull-shit.

Reply to
Thomas Moats

Were you by chance a bored suburban kid, or were you the kid behind the counter at the hardware store (or both)?

Ouch!!

Forget for the moment that you are technically right. You think you could convince the management, lawyers, insurance companies, and stock holders that, statistically over the lifetime of 20 million vehicles, the perfect conditions resulting in huge publicity and multi-million dollar lawsuits would never be met - not even one time? You know - seriously - taking your paint cans and eyedroppers into the conference room just might do it.

Reminds of the engineer that told me I was over-reacting when I went ballistic when a 3 foot long flame shot out of a known leaking hydrogen fitting due to a welder welding above it and showering down sparks - oh

- he had draped the hydorgen equipment with a canvas tarp before he started "to be safe". He was telling me that the conditions for hydrogen exploding were so specific that the chances of it happening were extremely small. The funny thing is that hydrogen in a process oven not 10 feet from that very spot where the flame shot out had exploded, blowing the door off of the oven so hard that it moved a 40 ton press a few inches when it struck it. Fortunately, no one was standing in front of the door at the time. Here's the kicker: That incident happened - not *AFTER* the 3 foot flame incident, but 3 years

*BEFORE* that - and he still told me I was over-reacting - that an explosion could never happen.

Saying "Oh - that could never happen - let's go ahead and do it" is how you end up on the 6 o'clock news. 8^)

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Reply to
Bill Putney

I really hate to be the one to say it, but there probably is some truth to what he says. I can't speak for the auto industry, but where I worked they eliminated probably 95% of the lockwashers used in assembly. They compensated by raising the torque values on the bolts and nuts. This was many years ago and it is still common to have to replace bolts during or after assy because the bolts begin to stretch and specified torque can't be achieved.

H
Reply to
Hairy

That's odd, my Service Manual still refers to it as the 'firewall'.

Reply to
PC Medic

But that isn't the reason that diesels take water in the fuel much more seriously. The reason is that diesels have very high pressure injector pumps. These pumps operate with very tight tolerances and any water that gets into them is very likely to cause instantaneous failure of a very expensive piece of hardware. That is why diesel engines have much better filtration sytems (dirt is as bad as water obviously) and take extreme measures to keep water out of the injector pump.

Matt

Reply to
Matt Whiting

Well, then don't....we are talking about the "auto industry".

So what? They have eliminated many lockwashers in the auto industry, but they now use other methods to lock the bolts/nuts in place. On GM vehicles, it's mainly thru the use of lock nuts, with either a deformed section of the thread, or a plastic insert in the upper portion of the nut. On bolts, a lot of "loctite" is in use from the factory.

There are also many bolts used on the newer engines that use "torque to yield", but these bolts are fine during their lifetime and are simply replaced when you have to loosen them. They are designed that way (to stretch when torqued). But that's really a different topic and has nothing to do with what lock washers are trying to achieve.

Ian

Reply to
shiden_kai

Hi...

If it isn't to be referred to as a firewall anymore; then I doubt it's to prevent my believing that a fire is possible...

Be more inclined to think they don't want me assume that their firewall would necessarily protect me from one.

Take care.

Ken

Reply to
Ken Weitzel

Correction - it was a 15? gallon tank in less than 1/2 hour. 1983? Toyota Supra. That is roughly 68 liters? Been a few years so I'm not 100% sure of the tank size.

The transfer unit used a roller cell type external EFI pump rated for something like 350HP or 150 liters per hour at 20 some PSI IIRC. Emptying the tank through the line was about 30% faster than through the access valve. Flipping a pair of valves on the unit and dropping the hose into the filler neck refueled the car in something like 20 minutes. Trying to suck the fuel out the access port with the valve installed was hopeless..

Reply to
nospam.clare.nce

I'm talking about doing it in the shop, where safety regulations REQUIRE a fuel transfer pump/tank unit. I made the unit we used for about 6 years while I was service manager - and it may still be in use today. I left the dealership in question about 18 years ago

Reply to
nospam.clare.nce

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