2003 suburban 5.3L surges on cold mornings
December 7th, 2015, 3:23 AM
#1
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2003 suburban 5.3L surges on cold mornings
2003 suburban 1500 5.3L surges on cold mornings (mid 20s and below). It also idles quite a bit higher than normal during this condition as if were an old carburetor rig. After it has been up to operating temp for a while this condition goes away. Codes give a multi cylinder misfire. Dealership thought intake gasket was possible cause. It has done this for a few years now during the winter months so I have my doubts about the intake gasket hypothesis. My instincts suggest it is an electrical component somewhere that wants to be in Arizona or somewhere warmer. Any thoughts?
December 7th, 2015, 9:32 AM
#2
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Welcome to the forum. As the engine warms up, the metal tends to expand and perhaps the intake gasket is the correct diagnosis as the expanding metal could seal a small leak.
December 7th, 2015, 9:58 AM
#3
For me, here in AZ, this is an indication of dirty injectors. as they gum up etc they have a hard time adjusting to the ecm inputs etc.
So I usually throw in techron, 20 gallon bottle on a 1/4 tank x 2.
.02
So I usually throw in techron, 20 gallon bottle on a 1/4 tank x 2.
.02
December 7th, 2015, 8:49 PM
#5
+ 2 for intake gaskets. +2 for viewing fuel trim at idle and 2500rpm. if its adding fuel at idle but comes back in spec at 2500 a vacuum leak is indicated.
leaking gaskets lean out the fuel mixture. when its cold, the mixture must be rich.
leaking gaskets lean out the fuel mixture. when its cold, the mixture must be rich.
Last edited by tech2; December 7th, 2015 at 8:51 PM.