My 1988 Chev pick-up truck (V6) wont idle. It starts great every time, but about 10 seconds after it has been started, the truck stalls. I have replaced the base gasket on the throttle body, cleaned the throttle body. Cleaned the EGR valve the best I could. Checked the timming and yet the problem still remains. What can I try next?

You might try some injector cleaner in the fuel. Is the fuel in the tank relatively fresh? Check the exhaust system for being plugged--kinked pipe, plugged muffler (should sound throaty if good). Try opening the exhaust by disconnecting the outlet side of the converter. You could try blocking the EGR valve with a metal plate between it and the manifold. I've seen EGR valves that leaked vacuum from the exhaust side and pulled outside air through the stem seal. Check the throttle position sensor for intermittant output. You might try some injector cleaner in the fuel. Is the fuel in the tank relatively fresh? Check the exhaust system for being plugged--kinked pipe, plugged muffler (should sound throaty if good). Try opening the exhaust by disconnecting the outlet side of the converter. You could try blocking the EGR valve with a metal plate between it and the manifold. I've seen EGR valves that leaked vacuum from the exhaust side and pulled outside air through the stem seal. Check the throttle position sensor for intermittant output.

Observe the fuel injector spray pattern with the engine running (a flashlight helps). It should be fan shaped--if partial fan or misdirected to the side, remove the injector (watch how it comes out) and inspect the lower end for blocked screen. Remove the screen while noting it's orientation. Try blowing through the injector backwards with compressed air. Rent a fuel pressure tester and read the pressure on the fuel line at the injector (it needs a 't' fitting that connects between the fuel line and the throttle body). It should be about 8 or 9 PSI with the engine running. If very low, suspect the fuel pump for being worn out. Observe the fuel injector spray pattern with the engine running (a flashlight helps). It should be fan shaped--if partial fan or misdirected to the side, remove the injector (watch how it comes out) and inspect the lower end for blocked screen. Remove the screen while noting it's orientation. Try blowing through the injector backwards with compressed air. Rent a fuel pressure tester and read the pressure on the fuel line at the injector (it needs a 't' fitting that connects between the fuel line and the throttle body). It should be about 8 or 9 PSI with the engine running. If very low, suspect the fuel pump for being worn out.