1995 Honda Acura - Won't Start When Low on Gas

You are correct there is a vacume, the vent in the cap does let air in but only after a slight vacume is formed.

Why you may ask, its so that when you have a crash the fuel is less likely to leak out if theres a vacume in the tank.

Drilling a hole would stop this safety feature from working, and invalidate the warrenty.

why dont you just keep the tank topped up?

The easiest solution as mentioned is to just keep it filled with gas. Your theory is correct, but the system should work right up until the car is empty. It seems to require too much vaccum pressure to get air into the tank. In rare cases, I have read that the vaccum can be large enough to cause the tank to partially collapse and that creates a whole new set of issues.

I admit to not being familiar with your exact system, but in general, air is introduced into the fuel tank through an evaporative emissions control system, usually some form of charcoal canister and a one way/pressure control valve. Could it be that some part of the system is blocked, such as an intake hose or one of the hoses that leads into the system?

I would much rather see you spend some time diagnosing and correcting this problem than have you drill a hole in the gas cap. A hole destroys the concept of evaporative emissions control and if you have to meet any type of emission standards where you live, you can bet that the car will not pass the test. Add to that the safety issues about having gas vapors possibly collecting in various areas of the car and you can see, it really isn't a good idea.

That should do the trick......tank caps have not had a hole in them for many, many years now because of emmisions on a warm day.....

Also it costs money to pay for petrol and for it to just evaporate away!!

The below should explain

http://www.familycar.com/CLASSROOM/emission.htm

http://alflash.com.ua/evap.htm

Your technical facts are correct- however your phrase where everybody wants to go to heaven etc is not true for a certain religion who are taught that the more infidels they kill the more reward they will get in heaven. Worrying is that approx 30% have this religion.

Well I'll definitely not be drilling a hole in my gas cap.

And I'll mention the event to my mechanic.

While I knew it was not recommended to let the gas in the tank get low, sometimes I do.

The car is getting pretty old. At least I had the timing chain replaced before the engine broke.

I've never run it out of gas completely, which I'm real intent on avoiding thinking that for a car this age there may be things in the tank that if I ever run it out of gas that might end up going through the engine, or clogging the fuel filter.

Since there is no water drain, like on an aircraft fuel tank I figure there is likely some water down there at the bottom of the tank.

First , I agree with the answer "writer" put forth. You have a problem which appears as a nuisance to you. Really , have someone familiar with your vehicle's evap system check it out . Sometimes it's so simple as a collapsed hose and you could get rid of this nusiance.

It doesn't have to be a big problem. If you paid someone to repair your vehicle's problem and they drilled a hole in the cap you probably would not appreciate that kind of repair.

Ive had a thought ( need to lye down now)

It could be the fuel pump is on its way out, As load increases on it as vacume builds up.

worth a try if you can get one cheap.

Reasoning The car was originaly designed to allow for running out of fuel, and restarting would just mean refilling.

So as yours wont run there must be a fault.

Try a new or used fuel pump

You could be partially on the right track that the pump might be partly on the way out, remember some modern cars have two pumps, or maybe the second pump has just given up the ghost, but there should still never be a vacuum in the tank (or pressure for that matter) on "common or garden" cars.....that is still wrong.

Any expanding or contracting air/gases must always pass through a charcoil filter attached to the tank in some way, the same filter that expanding gases sfrom the tank as the tank is filled or the petrol starts gassing on a warm day...or whatever....this allows the air pressure in the tank to remain around the same pressure as the outside air....

I expect there are some cars around where pressure (or a vacuum) is intentionally made in the tank, but there are probably very few of them around.....I would be interested if anyone can mention one of them....

Is the Honda A on the level, or going down hill or up hill when that happened? As those who have run on vapours on a trip know, you alway hope to be (and car tank/pump designs typically favor) going uphill when fuel level is very low. [One can coast down to the filling station on empty, but not coast (or hand push) uphill very far.]

At almost empty (for a level car), the difference between fuel availability can be "re-startup-significant" at even slight differentials in car nose orientation between going-up and going-down. If this was the case for you, the hearing of pressure escape (a phenomenon which is not typically a harbinger of anything dastardly) in conjunction with no-start and go-start conditions could merely be coincidental.

Damaging the filler cap merely because you happened to let the fuel run too low hardly seems fitting!

Also, it could be a fallacy to see significance...when first cranking might have merely primed the pump, or primed the rail (ready for the second crank) of a fuel delivery system that had just been allowed to run partially dry...in an intervening opening of the fuel tank. These kinds of troubleshooting rush judgments happen all too often.