Questions and Answers

Honda Hates The Cold Q. Greetings!! I have a 1989 Honda Civic Hatchback DX, 5-speed, 4 cylinder, dual point fuel injected, no A/C, no cruise, (no anything), with 134,000 on it. I have had fits with this most irritating and intermittent problem.

While driving in colder Montana weather, the engine hesitates, loses power, and eventually stalls. This happens only in the wintertime, and has done so the last two winters. Once the car dies, I can usually wait a few minutes, then fire it back up again and make it home. I've smelled gas strongly during these times, and I'm convinced the engine is flooding and causing it to stall. The check engine light does not come on during these periods.

This latest time it flooded so bad I still haven't been able to start it. Fortunately this happened in the garage prior to even leaving the house. It was about 15° F last night and sure enough when I tried to start it I pulled the cover off of the throttle body and the whole intake was saturated with gas. I beg your assistance on the following:

* Any ideas on what could be causing this flooding and why it is temperature dependant? How would you go about troubleshooting this? I've taken it to the dealer once and they couldn't help me due to the intermittent nature of the problem.

* What's the best way to deal with this flooded engine in order to get it going again (it's still dead in the garage.) Any advice would be greatly appreciated.

Best Regards,
Brady

A. The two things I would check first it the Coolant Temperature Sensor (CTS) and Idle Speed Control Valve (ISCV). If the CTS is starting to go bad, it will tell the computer it is colder than it actually is and the computer will add fuel to compensate. On the other side if the ISCV is not operating correctly, it will not allow enough air to enter to mix with the fuel. Basically it is either too much fuel or too little air.

Now the fly in the ointment is that it happens while you are driving the car as well. This, I do not believe, is related to the starting problem. I think what is happening is as you drive the throttle body is icing up and choking off the engine. When it finally dies and the heat of the engine has a few minutes to melt the accumulated ice, the engine will start and run until the ice forms again.

There is a flexible heat tube that goes from a sheet metal chamber around the exhaust manifold to the air filter housing. Inside the housing is a temp sensor that measures the temperature of the incoming air. if it is too cold, it will open a door and allow air heated by the exhaust manifold to enter and close off the cold air intake. This is how the icing problem is eliminated. If that heat tube is missing or the sensor or door motor is not working, then the warm air can not enter. Since it is vacuum operated, I would check the vacuum supply and lines as well.

The best way to deal with a flooded engine is to not any more fuel to it. Some models have a "clear flood" mode. If you hold the gas pedal to the floor while cranking, it shuts off the fuel and allows the engine to clear itself and start. A check of your owners manual will tell you if your car has this feature.

Lacking that, the best thing to do would be to pinch off the fuel feed line, hold the throttle wide open and crank the engine until it clears. Now keep in mind neither method is foolproof although it does work 90% of the time. Sometimes the plugs, especially older ones, will be so fouled that they just won't fire. The only thing to do in this case is to remove the plugs, clean them, or replace them, and reinstall them.

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