Fact or fiction

Can running your vehicle out of fuel, harm/damage your vehicle in any way? If so how and why? How do you know? Please no myths.
This is an attempt to debunk a myth. Any information obtained will be used for said purpose. :rofl:

Any other myths to bust?

In a turbocharged engine it will run lean and there will be a very big chance that you will have detonation. this could also happen in a high boost supercharged application. as far as n/a motors are concerned it probably wont hurt anything but it will be a pain to get it started again.

you can burn your fuel pump

This might be a myth because what I know is only what I was told by somebody who knows more than me...I was told that mixing different companies gasoline, different octanes ect can create a little bit of water in your tank...When your car runs low on gas it can ccidentally pump water into your cylinder, which will mess up combustion, and timing.

Any hardcore proof/evidence?

I heard this from somebody, who heard it from somebody, who heard it from someone else. But I have never seen or heard how this has been proven. ANY input is appreciated.

you can burn your fuel pump

How if the fuel pump only operates at one speed as designed?

This might be a myth because what I know is only what I was told by somebody who knows more than me...I was told that mixing different companies gasoline, different octanes ect can create a little bit of water in your tank...When your car runs low on gas it can ccidentally pump water into your cylinder, which will mess up combustion, and timing.
Gas station pumps have water seperators (most) to deal with condensation in storage tanks. Aside from condensation in the fuel tank, (very minimal if at all) where would the water come from? Gas floats on water, therefore water goes to the bottom of the fuel tank, most fuel tank pickups draw from the bottom of the tank inhibiting the possibility of water in the tank.

How if the fuel pump only operates at one speed as designed?


The fuel pump relies on the fuel in the tank for cooling. no fuel = no cooling = burned up pump. This applies to fuel injected vehicles with in-tank pumps.

I also applies to diesel engines, which use the fuel for both cooling and lubricating the pumps.

The fuel pump relies on the fuel in the tank for cooling. no fuel = no cooling = burned up pump. This applies to fuel injected vehicles with in-tank pumps.

I also applies to diesel engines, which use the fuel for both cooling and lubricating the pumps.

Yeah, but that can only happen if you were to continually try to start it when empty, right?

If the tank is almost empty, and the pump is trying to build and maintain pressure, it will burn up. or, burn out, more to the point.

Best thing to do, is not run low on fuel.

If the tank is almost empty, and the pump is trying to build and maintain pressure, it will burn up. or, burn out, more to the point.

Best thing to do, is not run low on fuel.

Oh you really got my curriosity up. Went to a salvage and got a fuel pump from an '89 V-6 Camaro with 216k miles for $10. In the garage connected to a 60 amp battery charger and battery. Pumped 50 psi with water when I started 4 hours ago. I'll pressure check it again (if its still running) at 10 hours and every 5 after that.

Can running your vehicle out of fuel, harm/damage your vehicle in any way? If so how and why? How do you know? Please no myths.
This is an attempt to debunk a myth. Any information obtained will be used for said purpose. :rofl:

In 1990 I got a brand new, from the factory, special order built for me Ford F150 with 2 tanks.

I always fill both, then run on the rear tank and switch to the front tank, the thought being, I never have more weight behind the rear axle than in front of it (hey its only 120ish lbs but every little bit helps)

Since the gauge responds slightly differently depending on tank, I use as my signal to switch: the rear tank running out of gas and the engine starting to buck.

I have been doing this for over 214000 miles.
I have original fuel pumps (but not tanks, those little plastic shields that come as part of the 4x4 package seem to trap moisture and acid...)
Both pumps make the same noise they did when new.

But the kicker is, I *can* do this as I have 2 tanks, running out in one just requires a switch flick. I doubt very much people in cars with one tank get very low because the alternative is a long walk, and we know how americans hate to walk...

Checked pressure on test pump. Still 50 psi. Still sounds the same. Put it inside an empty ice chest to trap heat, and maybe simulate an empty fuel tank. Was only slightly warm to the touch.

Quaddriver: Thats amazing, 214,000 miles and 14 years of continously running out of gas. According to the handfull of myth believers I know, you should have went through alot of fuel pumps, countless filters and injectors, and a few engines. Have you had ANY mechanical problems that might have even been remotely related to doing this?

I ran my 89 Cavalier out of gas several times before I figured out the gague was/is incorrect. That was 15 years ago, I still have the factory fuel pump at 300,000 miles. Doesn't seem any harm was done.

In a turbocharged engine it will run lean and there will be a very big chance that you will have detonation. this could also happen in a high boost supercharged application. as far as n/a motors are concerned it probably wont hurt anything but it will be a pain to get it started again.

Turbo and sc theory sounds very realistic. Anybody else back that up?
But to restart on a previously empty tank: Electronic non mechanical injection (mechanical pump is rare in injected gasoline applications) Turn ignition switch off and on two or three times (cycling the priming function of the pump) then start. Old school carbureted with mechanical pump: Pour equivalent to three teaspoonfulls of gas into carb. choke stack, start and allow to idle for a minute or two. Repeat if needed. If electric fuel pump: start as normal. This info came from a few owners manuals I've seen. I still havent been properly instructed on how to restart a rare but existant fully mechanical gasoline injection system.
I hear they realy are a pain. Does anybody have any experience or knowledge of them?

I ran my 89 Cavalier out of gas several times before I figured out the gague was/is incorrect. That was 15 years ago, I still have the factory fuel pump at 300,000 miles. Doesn't seem any harm was done.

300,000 miles. Pure G.M. quality? 2.2L?

Quaddriver: Thats amazing, 214,000 miles and 14 years of continously running out of gas. According to the handfull of myth believers I know, you should have went through alot of fuel pumps, countless filters and injectors, and a few engines. Have you had ANY mechanical problems that might have even been remotely related to doing this?

well aside from maint stuff, at 175K the pinion bearing went out on the rear axle so I rebuilt that, and fairly recently at 211K I lost the OD spring/roller clutch so I rebuilt the tranny. not sure I can blame either on the fuel pumps tho.

Pump still running, full 50 psi, just slightly warm.

hum this thread might turn into.... Fact or Friction:icon16: at some point.

That 1989 is a 2.0 with 88 horsepower. Hold on to your seats folks.

My test pump was still running and sounding just fine and still produced 50 psi when I disconnected it at noon today. No burnt smell or excessive heat. I believe it might be safe to say that "burns up the pump" is eliminated. What about further down the line?

Come on. Anybody? Ok how about that old sugar in the gas tank myth? (sugar dont mix with gas, chemically impossible, stays granular in tank and is caught by the filter clogging it) Myth believers say it "blows up" the engine.

I have head that myth is that true??

I have head that myth is that true??

Which one? The sugar? No. It only clogs the fuel filter and possibly the "pre-pump sock".
The out of gas? Personally still undecided. But leaning toward no.
Have you heard anything that you think might be a myth?

if your fuel pump is in the gas tank without gas You WILL burn your fuel pump

Again this is a depends situation...

If you were running a top fuel dragster and the fuel rail stopped releasing fuel under full acceleration, you would end up with a very large bill for parts and a lot of labour picking up the parts around the strip.

An old 500cc two-stroke MotoGP bike at full speed along the front straight at Monza would lunch itself too. It would be leaned out and no lubrication...

In an average domestic car cruising along the road - probably would not have any significant effect. Not enough revs, heat or load.

if your fuel pump is in the gas tank without gas You WILL burn your fuel pump

READ the ENTIRE thread.
Quit just repeating yourself. And if you believe this is realy true, how do you realy know?????!!!!!
See also post #s 13, 15, 21, and 24 !!!

Great experiment. I wait to hear the final results after several hours of dry running. Thanks for donating your time and effort and ten dollars to the education of the forum.
Jake

Great experiment. I wait to hear the final results after several hours of dry running. Thanks for donating your time and effort and ten dollars to the education of the forum.
Jake

UUUuumm, READ THE WHOLE THREAD.

I don't care if you believe me or not but my story is all truth and nothing but the truth.

My friend is a poora$$, he doens't work and his parents pay for insurance and gas. He drives an 89 toyota corola that we have literally revived from the flesh eating virus (RUST). He had half fenders and three quarters of his doors. So he obviously didn't care for it. He always let the gas tank near empty. He stuck on to my every word as gold when I told him that "a gas tank has a 10km reserve that you don't see on your guage". So he kept running his tank low even though I told him that he shouldn't do it often because his fuel pump might die. He said that he didn't give a crap, the entire car was only worth $100-200. The funny thing is, months later, he had a fuel pump failure. Maybe it was just due to old age but the point is THE FUEL PUMP DIED. I have no theoretical explanation to what happend but that's what happend.

he burned the pump its not rocket science

The warning to never run out of gasoline was ment for electric (in tank) fuel pumps. They lose their cooling and in some cases lubrication and start to wear. I just rebuilt a 4.3 for my neighbors mud truck and he runs his tank dry all the time. One day the pump will fail him and he will know why thanks to me bugging him about it.

Please Read The Whole Thread Before Posting A Reply

I havn't read all the way through this, so I don't know if this has been posted.

The way I was always taught to relieve fuel pressure was to siphon out the gas, and let the engine run until it dies from lack of gas.