When to use a scan tool for intermittent stalling?
When attempting to diagnose an intermittent stalling problem, therefore, it is important to always use a scan tool to first check for any codes that might shed light on the condition, and secondly to look at all the essential sensor inputs to see if they are within range and are supplying accurate information to the PCM.
What makes an engine run and idle without stalling?
Every engine needs three things to run and idle smoothly without stalling: a correct air/fuel ratio, sufficient idle speed for the idle load, and a good spark. If any of these is lacking, the engine may stall. Cold stalling problems are the most common because the engine needs a richer fuel mixture to maintain idle speed until it warms up.
Why is my scanner so slow with WiFi?
When you use a Wi-Fi connection, communication may become unstable (for example, signal interference such as noise disconnects the scanner and computer or the transferring speed of scanned images becomes slow) depending on where you use the ScanSnap.
Why does intermittent stalling occur in a car?
One of the more unusual causes of intermittent stalling we’ve heard about is a defective vehicle speed sensor. When the vehicle stops moving, the PCM may not engage the idle speed motor (carbureted engines) or idle air bypass motor (fuel injected engines) so the engine will idle normally.
When attempting to diagnose an intermittent stalling problem, therefore, it is important to always use a scan tool to first check for any codes that might shed light on the condition, and secondly to look at all the essential sensor inputs to see if they are within range and are supplying accurate information to the PCM.
What does it mean when your car is stalling at idle?
Problems with idle speed —things like slow idle, fast idle, rough idle, or stalling after idling for a few seconds—are symptoms that something is wrong with your engine. These should be investigated, diagnosed, and repaired as soon as possible.
What to do if your car won’t idle?
The Fix: Set idle speed to specs. There may be some type of ignition problem. The Fix: Check and replace distributor cap, rotor, ignition wires, and spark plugs. There may be a fault in the computerized engine control system. The Fix: Bring your car to your mechanic or dealership to check the engine control system with a scan tool.
Why does my car stall at a stoplight?
Rough Idle in the Cold It’s a cold day and you’re stopped at a stoplight. You take your foot off the gas pedal to apply the brake, but your engine begins to idle very roughly, and then it stalls. Yet, when you restart the engine and run the car at higher speeds, it seems to run fine, or at least more smoothly.
One of the more unusual causes of intermittent stalling we’ve heard about is a defective vehicle speed sensor. When the vehicle stops moving, the PCM may not engage the idle speed motor (carbureted engines) or idle air bypass motor (fuel injected engines) so the engine will idle normally.
Is there check engine light for intermittent stalling?
Many times, there will be no check engine light and no fault codes to give you a clue as to what might be causing the engine to stall. So the trick to diagnosing an intermittent stalling problem is to catch the vehicle when it’s acting up — and that rarely happens when you have the vehicle in your shop.
Can a scan tool be used to test idle speed?
If you don’t have a scan tool that can do an idle speed test, or the vehicle does not have this capability, you can still test the response of the ISC system by turning on the A/C to max. If the ISC system is working correctly, the PCM should adjust idle speed to keep the engine from lugging down when the A/C compressor engages.