1994 Civic VX stalls when gas tank gets below one-quarter full

I have a 1994 Honda Civic VX with the 1.5 liter VTEC-E engine and 145,000 miles. For the past year or so it has been stalling when the gas tank gets low, about 3 gallons or less in the tank. It?s pretty strange. It runs perfectly fine when the tank is full or half-full, but then it just stalls when the tank gets down to about a quarter full. Sometimes it restarts and I can make it to a gas station, and sometimes not, but if I simply fill up the tank, it runs fine until it gets down to about a quarter of a tank again. To try to solve the problem, I have replaced the following items, one by one, none of which has solved the problem:



Fuel pump

Fuel filter

Fuel pressure regulator

Evaporative emissions canister

Engine Control Module (with a used unit)

Main relay, containing the fuel pump relay

Fuel level sending unit

Ignition coil



I took it to a Honda dealer for the problem, but all they found was a problem with the ignition coil, which I replaced, but that had no effect on the stalling problem (but cured a flickering battery light - the coil was arcing).



Also, I did not drop the gas tank and clean it after replacing the fuel pump as the repair manual recommended, but I took a peek inside the tank and noticed no obvious debris. And the plastic mesh filter at the end of the old pump had no visible debris on it.



So, does anyone have any suggestions on what might be wrong? Thanks!

[b]The symtom you describe sure sounds like a weak fuel pump. So it’s possible that the replacement fuel pump is defective. But before I would go back and replace the pump, I’d check the fuel pressure when this event occurs.

When the fuel in the tank nears the point where this occurs, connect a fuel pressure gauge to the fuel rail routing the hose under the hinged end of the hood. Now tape the gauge to the windshield, and take a drive around the neighborhood. When this problem happens, check the fuel pressure.

I hope you didn’t get a bunk new fuel pump!

Tester[/b]

This may sound unusual, but have you checked the capacity of the tank ? I had a guy with a 1994 Accord who was complaining about how relatively often he had to stop for gas, and it turned out his fuel sending unit was bad (reading empty, when he still had a half tank). Maybe yours is reading 1/4, but is really almost dry.
jeff

You said the plastic mesh filter looked fine. Did you replace it, or did you re-use the old one? That is the fuel strainer, and at least the fuel pumps Ive bought wont even guarantee them if you dont replace the strainer with the pump. The strainer is a primary fuel filter.

Since youve replaced the sending unit, maybe the gauge in the dash is bad. Or maybe there is poor wiring somewhere between the sender and the gauge, causing a false reading.

Did you check the line to the charcoal canister to see if it’s plugged/kinked? If it is, the gas tank would build up a vacuum as the gas is upmped out.

You could check this by removing the gas cap when the problem occurs. If you hear a big “whoosh” of air entering the tank and the problem goes away, you can bet on a plugged line, since you’ve already changed the canister.

  • mountainbike

The problem didn’t change in any significant way when I changed the fuel pump, but I’m curious about the fuel pressure so I’ll give it a try. Thanks for the idea! (I have run a car out of gas a few times in my life, and when this particular problem happens, it sure feels like it’s running out of gas.)

The fuel level seems to register the same now that I have the new sending unit in the car versus the old sending unit, so I doubt it’s the sending unit. I say that because with the old sending unit installed, when the car would stall I would fill it up and it would take 7 to 8 gallons to completely fill it. The tank capacity is 10 gallons and the fuel guage would read a quarter to an eighth full when it would stall. Now, with the new sending unit, it still reads a quarter to an eighth full when it stalls, and the car still takes 7 or 8 gallons to fill the tank. So it doesn’t seem to be the fuel level sending unit.

This is a very good idea and of course very easy to test, so I’ll give it a try. Thanks!

The new pump had its own new mesh filter on the end of it, so of course I left it on. The new pump just has not had any significant effect on the problem.