01 Suburban 5.3 Hard Start When Cold

[mike g 09]

Hello.

 

I have an 01 suburban with a 5.3 v8 in it.

 

When the temp drops much below -15 F, it won't start very well. (Past two winters). It will turn over beautifully, but won't fire. Typically it will go like this: I'll plug in the block heater over night (thus the easy turning), and turn on the key for about 20 seconds before cranking it. It won't fire, so I turn the key to run for another 30 seconds, and then try again. It sometimes will start like this, but when it is -20, to minus 30 degrees F, it may not start until it warms up around noon.

 

I can hear the fuel pump in this situation, sort of a weak vibrating motor sound, difficult to describe "rrrrrrrrr"

 

Thoughts? Could it be the fuel pump?

 

Also, on a possibly related note, it throws the P0446 code,(EVAP system), which I attribute to living on gravel roads. ((I tried to remove the evap canister, but had a real problem removing the fittings, so that problem is unfixed at this time)

 

Thanks in advance,

[mike g 09]

bump.

[bigredmariner]

Sounds like the throttle body needs cleaning, the blade may not be opening up enough during start up due to carbon build up. Is the 2001 cable operated TB? I can't remember.

 

The evap code wouldn't cause any of this nor would it effect anything. It's just an emissions issue, sometimes it will decrease your mpg's slightly but the code isn't gonna put you stranded on the side of the road.

[mike g 09]

Sounds like the throttle body needs cleaning, the blade may not be opening up enough during start up due to carbon build up. Is the 2001 cable operated TB? I can't remember.

 

The evap code wouldn't cause any of this nor would it effect anything. It's just an emissions issue, sometimes it will decrease your mpg's slightly but the code isn't gonna put you stranded on the side of the road.

 

Hey, thanks for the reply. I looked, it is a cable-operated throttle body. Are the throttle bodies known to have carbon buildup, and cause problems like this? I guess something like that hadn't occured to me.

[ColoradoSkiCountry]

They sure are. I'd go ahead and spray in some TBC and let it soak for a bit then dry it out with a rag (what you can reach) I'm still certain that you have a fuel pump and or FPR issue.

 

 

Sounds like the throttle body needs cleaning, the blade may not be opening up enough during start up due to carbon build up. Is the 2001 cable operated TB? I can't remember.

 

The evap code wouldn't cause any of this nor would it effect anything. It's just an emissions issue, sometimes it will decrease your mpg's slightly but the code isn't gonna put you stranded on the side of the road.

 

Hey, thanks for the reply. I looked, it is a cable-operated throttle body. Are the throttle bodies known to have carbon buildup, and cause problems like this? I guess something like that hadn't occured to me.

 

[mike g 09]

S

They sure are. I'd go ahead and spray in some TBC and let it soak for a bit then dry it out with a rag (what you can reach) I'm still certain that you have a fuel pump and or FPR issue.

 

 

Sounds like the throttle body needs cleaning, the blade may not be opening up enough during start up due to carbon build up. Is the 2001 cable operated TB? I can't remember.

 

The evap code wouldn't cause any of this nor would it effect anything. It's just an emissions issue, sometimes it will decrease your mpg's slightly but the code isn't gonna put you stranded on the side of the road.

 

Hey, thanks for the reply. I looked, it is a cable-operated throttle body. Are the throttle bodies known to have carbon buildup, and cause problems like this? I guess something like that hadn't occured to me.

 

 

 

How likely is it to be the fuel pump or FPR? Should I just buy a fuel pressure gage and check the pressure?

 

I would like to be proactive on this -- I really don't want a bad fuel pump or something like that, in January....

[ColoradoSkiCountry]

most definitely I would suggest checking the fuel pressure first before replacing. Someone else will need to give you what the fuel pressure should be.