Posted by Reel Man on March 17, 19100 at 22:22:20:
In Reply to: Re: Weak valve springs posted by Traveler on March 16, 19100 at 22:01:02:
Thanks Traveler for the info, however, all the items you mentioned have been investigated by a whole lot of mechs, including Chevy dealerships, and most if not all electronic and fuel delivery systems have either been changed or tested thoroughly, and the culprit has eluded everyone to date. The question re: weak springs was yet one more attempt to isolate the problem.
: 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.