1999 Chevy 5.3L issue

[MacGyver]

My truck had developed a stumble and backfire only when the engine is cold. After a minute on the road it runs like a champ. No SES light or any other warning.

1999 Chevy 5.3L with a whopping 51,000 miles.

Any ideas?

[Trim'd Up]

Maybe intake manifold gaskets. My cousins truck did the same thing and that's what it was. It never showed an idiot light, but I think it showed a fault of some kind on the scan tool if I remember right. It has been a while.

[MacGyver]

I have Diacom marine software. I wonder if it'll work on a truck :huh:

[MacGyver]

I forgot to mention, it starts and idles just fine. It only stumbles when I try to accelerate.

[Ted]

It is the intake gasket, they leak cold and since the computer is not in closed loop, it will not pick up the lean condition.

[MacGyver]

Thanks Ted. From what I've been reading online, this is a common problem. I want a new truck anyway :26: