Sure enough....I replace the master cylinder reserve, exhaust system, bearings, and now the truck won't start. At first I thought it was the damp, rainy days we had, as it turns over and cranks but will not fire. But two years ago I replaced the cap and rotor and that solved the damp issue. So today I get some starting fluid, spray into carb. Fires right up then stalls! Here comes my next question...when i turn the key to accessory, should I hear the fuel pump prime? All I hear is a small clunk, sounding like it is coming from under the hood. I hear it on my 1999 4.3 Astro. Things replaced over the last two years: coolant sensor oil pressure sensor cap-rotor-plugs-wires Thanks!