Q&A

 Master

The truck doesn't have a choke like older carburetor trucks had. A sensor in the cooling system tells the computer in you car the temperature of the engine coolant and adjusts the fuel mixture accordingly. The computer also looks at ambient air temperature, crankshaft and camshaft position and the composition of the exhaust gas to determine if the engine is running lean or rich. It is hard to speculate what the problem could be without experiencing the problem first hand or doing basic diagnostic test too many things could cause this problem.

These trucks do not have a chock. The ECM controls the fuel mixture under all operating condition by useing data collected from verious under hood senors. The GM 4.3L V-6 in notorious for intake gasket failures with will cause problems such as you are having.Check your intake vaccum at normal operating temp. Below 16-17 inches is a strong indicator of a leaking intake. Other signs are having a visiable coolant leak on the ground under your truck when it is warmed up, frequently having to add coolant to the recovery tank, intermittant periods of over heating, and loose of heater output in cold weather. If you are not an experanced "gear head" this is a job best left to a professional Tech.