I have a 1996 Jimmy with a 4.3 Vortec and 225000 miles on it. It was running fine last week and I went out to start it today and I heard something a under the hood and saw a little smoke. The engine will start but idles up to 3500 RPMs and then cuts out. Any idea what this could be or what I should check?

 

Large vacuum leak? Take a look at all of the vacuum lines and make sure that they are all connected properly.

 

I didn't think of that, I will try that today.

Thanks,