* Throttle Position Sensor (TPS): A faulty TPS can provide inaccurate readings to the engine control module (ECM), leading to improper fuel delivery. A slightly depressed gas pedal might be compensating for a faulty TPS reading. This is a common culprit in these symptoms.
* Crankshaft Position Sensor (CKP): The CKP sensor tells the ECM where the crankshaft is in its rotation. A malfunctioning CKP sensor can cause starting problems, especially in cold weather. The ECM may be struggling to get the timing right for the fuel injection.
* Mass Airflow Sensor (MAF): A dirty or faulty MAF sensor provides inaccurate air flow readings to the ECM. This can result in a lean fuel mixture which is hard to start in cold weather.
* Fuel Injectors: While less likely given the gas pedal slightly helping, clogged or failing fuel injectors could be contributing to a poor fuel mixture.
* Ignition System: Though less probable with a consistent crank, a weak ignition coil or other ignition component could be having trouble firing reliably in the cold.
* Cold Weather Issues: The symptoms are exacerbated by cold weather, suggesting a fuel delivery or ignition issue which is amplified by temperature.
Why depressing the gas pedal helps (sometimes): By depressing the gas pedal, you're potentially adding more air to the mixture, which can help compensate for a lean condition caused by a faulty sensor (TPS, MAF) or a fuel delivery problem. However, this is a temporary fix and masks the underlying problem. It's important to find and fix the root cause to prevent damage and future problems.
What to do:
1. Check the error codes: Use an OBD-II scanner to read any trouble codes stored in the ECM. This is the quickest way to pinpoint a possible culprit.
2. Inspect the TPS, CKP, and MAF sensors: Visually inspect these sensors for damage or dirt. Cleaning the MAF sensor with MAF cleaner is a relatively easy and inexpensive first step, but replacing sensors might be necessary.
3. Check fuel pressure: A mechanic can test the fuel pressure to ensure the fuel pump and injectors are delivering the correct amount of fuel.
4. Consider the ignition system: While less likely, have a mechanic test the ignition coil, spark plugs, and ignition wires if sensor replacement doesn't solve the problem.
Ignoring this could lead to more significant engine problems. It's advisable to have a mechanic diagnose the issue as soon as possible. The temporary fix of depressing the gas pedal should only be used as a means to get the car to a shop.
