Engine Problem, Please Help! - Problem Solved Options

[fgvillegas]

Hi Guys,

I have a problem when I have just started the engine specially when the car was not used for an hour or so. And the problem is sure to happen on cold start.

Everything seems normal when I start the engine. But when it starts running, it seems like there is not enough fuel being supplied or maybe the throttle is a little sticky. The reason why I say this is because when I press the gas pedal as I do normally, I experience some hesitations. And when I press the gas pedal a little more the car will suddenly run fast and throw my passengers aback.

What I need to do is to rev the engine to about 3K or so whenever it hesitates. After doing this for maybe 3 to 5 times, the engine will start to work as expected. The longer I drive, the smoother it gets.

What could be wrong? Could it be the following?

• Injectors
• Spark plugs
• PCV valve
• Fuel filter
• Fuel pump
• Sticky throttle

What confuses me is: Why does it only happen at the start? I was thinking that it should always be the same if the problem is any of the above.

Please help!

Thanks

This post has been edited by fgvillegas: May 4, 2010 - 1:37 AM

[fgvillegas]

Hi Guys,

I finally figured what the problem is. It's the O2 sensor.

I first reset to ECU before disconnecting the O2 sensor socket then I zeroed out the air correction of my SAFC2. When I started the engine. The problem is gone. Just to check further, I run the car and see if the hesitation is still there. It's gone too.

Just to make sure that the problem is the O2 sensor, I reconnect the socket again and restart the engine. The problem went back.

For now, I just disconnected the socket of the O2 sensor while waiting for my order to come. I know that the default setting A/F setting of a disconnect O2 sensor is not as good as a working O2 sensor. But for now, I can live with that. It's better than having a rich A/F ratio setting using the SAFC2.

Thanks to all who helped and responded.

I hope this will also help anyone who may experience the same problem.