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2004 Chevy Venture, Failing compressor?

This started out as an intermittent problem after I would run the a/c for a bit. Now it happens every time I get in the van regardless of if I turn on the a/c. The engine begins acting like I am pressing the gas pedal, but not flooring it. I have to press hard on the brake in order to get the vehicle to stop because it is trying to race ahead and I don’t have to press the gas until around 45 mph. What in the world is going on with my van? If I throw it in neutral it just goes nuts. I have been pulling over, shutting off the van, waiting a few minutes, and then cranking up again. It could take a couple of minutes for it to start again or it will do it right away. Help please.

Throttle butterfly valve could be catching in the throttle body, the mechanical linkage between the pedal and the throttle could be getting stuck, the IAC could be broke or stuck. Air leaks can cause this too sometimes.

Anyway, something’s definitely amiss. Since it is a serious safety issue, you should get this check straight away by a mechanic or someone knowledgeable. A visual inspection would be the first thing to do. Is the check engine light on btw?

No check engine light. The IAC sounds familiar. I think I have had that replaced in the past. Been a bit though. I will check for air leaks tomorrow myself in the daylight. Could it be caused from a poorly connected air filter hose?

I will report back tomorrow. Thanks for the late night help.


Air filter hose? Possibly. The MAF requires the air flow stream through that hose in the way the car designers specified. You might see some weird looking appendages on that. Common in some cars. Those are to make the airflow stream correctly. Otherwise it confuses the MAF and makes it think there is more or less air moving into the engine than there really is. But for it to cause the symptoms you report, that’s something I’m not familiear with, and it would have to be pretty severe constriction I think. I doubt that is it.

Generally if a hose that affects engine operation is improperly connected of fallen off it’ll create a vacuum leak, and that causes a whole different set of symptoms.

The sensors/systems that are primary in determining how much gas is fed to the engine that are liekly to affect idle speed are

Idle Air Control; that adjusts idle speed
Mass AirFlow sensor; that sends the “how much air is flowing in” signal to the ECU
Oxygen Sensor (often called the O2 sensor or the Air/Fuel sensor) that tells the ECU that the engine needs more or less fuel to get the proper ratio

The crank (or cam, depending on the engine) Speed Sensor is a variable too, but your symptoms don’t fit that type of failure.

Most parts stores will check the ECU for stored failure codes. Even though you have no light, you probably have codes. Get them checked and post them.