Chevy Malibu Stalls At Idle

Question:
I replaced the battery, exhaust resonator, fuel pump, and fuel filter on my 2005 Chevrolet Malibu Classic. Still, the engine dies when I turn on the air conditioning. Engine does not die when A/C is off, but does seem to surge at idle occasionally. Three different mechanics have looked at it, and none know what is causing the problem. Any suggestions? Could it possibly be that I need new spark plugs and/or wires? 2005 Chevrolet Malibu Classic 2.2 liter. I replaced battery, resonator, fuel pump, and fuel filter.

Answer:
No, i highly doubt that the spark plugs and plug wires are causing your problems. This 2.2L engine does not have spark plug wires anyway. It hasthe coil over plug setup with spark plug boots instead of wires. There can arc and cause a misfire though.

Without a check engine light or codes, this can be hard to diagnose. But by what you are describing, it does just sound like carbon buildup in the throttle body bore and plate. This is a very common problem on the 2.2L Chevy. First, clean carbon from throttle.

On older cars, the idle was controlled by what is called the Idle Air Control Valve, or IAC motor. When they malfunction the idle cannot be controlled correctly, and the car can dies out or not even start. On today's cars, the throttle is electronically controlled and there really is no idle control motor. Idle is controlled by the throttle itself. The computer (PCM) sends signals to the throttle to open or close it at idle depending on other sensor readings.

One of the things the computer looks at is if the A/C compressor is on. When the A/C is on, this puts a load on the engine, so the idle comes down. The electronic throttle body will compensate by raising the idle a little. If it cannot do that, the car may surge as it is trying to adjust it and could possible stall out if it can't.

You need to clean the throttle. That may all that may be needed. Remove the air duct at the throttle, open it with a your finger, spray carb or brake cleaner on a rag and wipe inside the throat real good. Also spray all around inside. Get out any dark material you see. Put the duct back on then take it for a ride and blow it out real good- accelerate very hard several times.

The engine will stumble on the first start up and first few times pressing the gas pedal, but that is normal until the cleaner is blown out. Take it on the expressway, then get off and come to a stop and let it idle in gear for a minute. Shut Your Chevy Malibu off for a minute, then stat it back up and you should be fixed. Do all this with the A/C off.

Question:
Why do my car vibrate when I'm idled a light and it does not always start on the first start, i have to give it gas by stepping on the accelerator. 2004 chevrolet Impala 3.4L engine. P0300.

Answer:
Code P0300 engine misfire will not be caused by a bad mass airflow sensor, so you wasted your money on that part. Most misfires are caused by a bad spark plug, plug wires or sticking / faulty fuel injector. Check those basic things first. A good scanner will tell you what cylinder is having a problem so you can concentrate on that one instead of just guessing at parts.

Rough idle, and hard starting may be from a leaking fuel pressure regulator. When they fail, gas goes into the vacuum line and causes a rich condition. That is why you have to hit the gas to clear it out and make it start and idle better. Check the 3400 fuel pressure regulator (FPR).


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