How does a faulty cold start valve affect the running of my engine

One possible reason for this could be a faulty engine coolant temperature (ECT) sensor. The ECT sensor tells the engine control module (ECM) the temperature of the engine coolant, which is used to adjust the air/fuel mixture for starting. If the ECT sensor is faulty, it may be sending incorrect temperature readings to the ECM, causing the engine to not start in cold weather.

Another possibility could be a weak fuel pump check valve. When the fuel pump check valve fails, it can cause the fuel pressure to drop when the engine is turned off, which can cause hard starting in cold weather .

It's also possible that the battery is weak and not providing enough power to start the engine in cold weather. Cold temperatures can reduce the battery's cranking power, which can make it difficult to start the engine.

I would recommend taking your vehicle to a certified mechanic to diagnose the issue.

Hi, Billy. There are a few things that could cause the problem that you have described. A cracked ignition coil can cause these kinds of problems as well as a faulty O2 sensor. If the engine is running well when cold, no miss or stumble, then more than likely the coolant temperature sensor or (ECT) is faulty. You can check this by unplugging the sensor and trying to start the engine. If the ECT is the problem the engine will start and run normally. If the problem is still there then check Idle Air Control (IAC) valve.

yes

two things to check. First, check the EGR valve to see if it is sticking open. this valve is not activated until the engine is warm. This valve could also have a vacuum leak in its diaphragm so check the valve out thoroughly.

Second, there is an engine coolant temp (ECT) sensor that alerts the engine computer as to when the engine is warmed up. If this sensor is faulty and stuck in the full cold mode, it will tell the computer that the engine is cold even when it is fully warmed. The computer will then use the cold engine fuel schedule which is way too much fuel for a warm engine. The engine will run too rich and sputter. In this condition, the computer will schedule too much fuel for a warm start and the engine will flood. That is why you must wait for it too cool down and "match" the faulty sensor.

Note: the ECT has two wires going to it and is dedicated to informing the engine computer. It has nothing to do with the engine temp gauge on the dash board instrument panel. The sender for the dash gauge has only one wire. The two sensors are easily confused.

I'll be honest, it sounds like the transmitter in the key isnt reading. A key remake without the factory transmitter will start the car, but only keep it running for a few seconds before cutting power to the motor. your electronics will still run....This may be too obvious, but honestly, thats what it sounds like.

mcdevito75 here, Sounds like the Cold Idle valve or motor is bad, The fast idle valve or motor depending on your car allows the engine to run a bit faster when cold, the A/C compressor is also hooked up with a device that allows the engine to run a bit faster to handle the load of the A/C compressor or your cars air conditioning, I think your problem is a faulty cold idle valve / motor, have your auto repair shop check it out and replace.

Yes sir , you have a failing valve, soon it will snap in two....please have your head checked. You can do this yourself by placing a long-handed screwdriver , business end down to each cylinder while pressing your ear to the handle(while engine is running)...you will notice a definite difference when you hit which cylinder has the bad valve. Also makes sure the egr valve is clean and your exhaust recycle valve is not stuck.( located in the crossover pipe)

try coolant temperature sensor

mcdevito75 here, Sounds like a faulty cold start valve / sensor. Have the shop check out the cold start system of your engine.