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2001 Seoul Rocket dies when stops

I have a 2001 Hyundai Accent with 210,000 miles. I had had very few problems with the car in the past 11 years - 2 sensor problems, transmission related at 100K and oxygen sensor at 160K. I have done oil changes every 3000-4000 miles, transmission flushes every 30K, and timing belt replacements every 60K. However, within the last month, the car sometimes dies when I fast or slow brake to a stop. Due to the high mileage, I had the fuel pump and fuel filter replaced and had the timing/tuneup checked. There is no check computer light lit.

What else can I check?

The problem might be with the Idle Air Control valve. The IAC valve allows air past the closed throttle plate when the accelerator is released so the engine can idle. If the IAC valve and/or the idle air bleed port on the throttle body are dirty where air can’t enter the engine when the accerator is released the engine will stall.

You might try removing the IAC valve and clean it along with the throttle body with throttle body cleaner and reinstall the IAC valve to see if that fixes it. If not, then the IAC valve itself may be defective and requires replacement.

Tester

Does this only happen when your foot is on the brake pedal? A brake booster failing could cause a very lean condition and cause a rough idle and stall. Can you coast to a stop and it be OK?

Thank you Tester and W30post. I’ll look into both of your suggestions. The problem just occurred out of the blue. The stall is intermittent - maybe 2-3 times out of 10 when I stop or slow down the car. One time it happened on a 60mph freeway as I slowed down to turn left. My concern is getting rear-ended or losing power on a left turn. The engine is quiet normally so I didn’t notice that I had lost power until I went to press the gas pedal. The idle seems to be low. We have a farm with a gate to keep the livetsock in. One time, I stopped to open the gate and the car just died. Yesterday, I noticed the idle was low and somewhat rough.

I think Tester is on the money here then. A good upper intake cleaning and the IAC valve being cleaned should help.

I’m a fan of SeaFoam being used to clean the upper intake. You will kill a lot of mosquitos but it will run better.