Car stalling - is it water in gas tank or electrical?

I have a 1999 Honda Accord. I recently filled the gas tank at a local gas station. The tank was half full at the time. After driving about 25 miles, my car suddenly stalled. When I tried to start it, it would start then die withing 1 second. I poured in dry gas and that seemed to have cleared the problem until the next day, when it stalled again. The same thing happened when I tried to start the car and dry gas again fixed it. When it happened a third time, I took it to the Honda dealer and told them I might have water in the gas tank. They looked at it, said that it was my main relay, and replaced it. However, the next day, the same thing happened, only worse. I was about 8 miles from home and it stalled three times before I got it home. The last time, I kept the car in place but ran the engine at about 4,000 RPM for a couple of minutes. I noticed that the tachometer twice dropped to 0, then instantly picked up again to 4,000 RPM. I was upset at the Honda dealer so I took it to a mechanic recommended on this site. He kept the car for three days. He could not make it happen. He thinks that it is electrical but does not know which part. Before I brought it to him, I had probably poured about 8 bottles of dry gas into the tank since the problem started. So, could it have been water in the gas tank or is it electrical? Does anyone have an idea?

Thank you,

Alex Lopov

The tachometer dropping to zero might point to a defective distributor module. This module is what sends the crankshaft signal to both the tach and the engine computer. When the signals from this module become erratic, the computer has no reference for engine RPM’s and the computer shuts the the fuel injectors down. The module is that little plastic box mounted at the base of the distributor.


If you suspect water in the fuel, siphon some gas out of the tank into a clear jug or jar, leave over night and check for water in the bottom the next day.

Basically a sound idea probably, but aside from the safety issue (gasoline is fairly toxic) every car I’ve tried to siphon lawnmower gas from in the past three decades has had baffles in the filler pipe that make siphoning next to impossible. It would be possible to pump a sample out using the fuel pump, but it’s likely to be a bit risky as it is probably hard to do without spilling a lot of gas.

Last car I had that behaved like that did indeed suffer from water in the fuel tank, but the problem was that the water rusted the tank and the rust then somehow managed to form a large flake that periodically blocked the fuel filter.

So maybe, change the fuel filter (if there is one) and try to catch as much as possible of the gasoline that escapes during the process. Examine it for rust particles then leave it overnight to see if water separates out. If neither rust nor water shows up, move on for a while to other possibilities – ignition wiring, intermittent fuel pump, etc.

It is not unusual to have a bad ingnitor in honda dist. 97 to 02 model years.