Hard start on cold mornings; replaced plugs but did not fix; fuel filter?
If the vehicle runs normally otherwise, your fuel filter is likely not the problem. A plugged fuel filter would likely cause misfiring under load, such as when going uphill.
Make sure, by the way, that you do not touch the gas pedal when starting. That could make it hard to start.
Old fashioned cars used a choke to feed it more fuel for a cold start. Modern cars use a computer to feed the fuel injectors more fuel on a cold start, and rely on a sensor or two to know that it's cold.
Couple of possibilities here:
a) Has the check engine light been on? If you have a bad sensor, such as oxygen, throttle position, or coolant temp sensor, the computer may have an error code stored in it's memory about this.
b) How many miles on the vehicle? Some other problems could be leaky injectors, leaky injector 0-rings, or intake manifold air leaks, all making it difficult to start when cold.
A fuel pressure gauge on the fuel rail would tell you if a leaky injector is causing the fuel pressure to drop....then a cold start would be difficult if there is no pressure in the system.
If there is a leaky o-ring or intake manifold, the vehicle will typically misfire and/or light a check engine light.
×