Posted by Traveler on March 16, 19100 at 22:01:02:
In Reply to: Weak valve springs posted by Reel Man on March 16, 19100 at 20:45:40:
If it did have weak valve springs, that would affect high RPM operation and not idle. I've never heard of any such spring problem.
Bad idle on the TBI engines usually comes from 3 sources:
1.) leaking throttle body to manifold gasket
2.) EGR not turning off fully at idle
3.) Plugs, wires, or other ignition problem.
Less likely causes are a bad or dirty IAC motor and passages, dirty fuel injectors.