2001 Silvardo cold start issues

[MGT999]

My 01 5.3 Silverado does not like mornings. Now that the weather is cooler, it starts right up, but will idle up and then quickly fall. Starts sputtering, coughing badly and if I touch the gas, it will stumble and then the idle will race for second or so and then drop back to the cough/sputter again. Once warmed up, it seems to run fine and start fine, though I did just recently notice a little spark knock when you first hit the throttle.

 

So far, I've replaced the fuel pressure regulator, idle air control valve, cleaned the throttle body, fairly new fuel filter and nothing as fixed the issue.

 

Any thoughts??

[MGT999]

any help or advice would be much appreciated.....

[pwall]

Do you have access to a OBDII scanner that can pull any codes that may have been set ?

 

And welcome to

[GM-Tech]

Fuel pressure is critical, especially cold when it needs all the fuel it can get. So, check your fuel pressure.

[MGT999]

Do you have access to a OBDII scanner that can pull any codes that may have been set ?

 

I've heard Autozone will run the codes, so I can try that.

 

 

Fuel pressure is critical, especially cold when it needs all the fuel it can get. So, check your fuel pressure.

 

<{POST_SNAPBACK}>

 

 

 

 

I replaced the fuel pressure regulator, but maybe it's bad. Wheres the best place to check the pressure at?

 

Thank you both for the help!

[GM-Tech]

Wheres the best place to check the pressure at?

 

There's a test port on the fuel line towards the rear of the engine.