Any Ideas?
135,000 miles and started noticing random problems with the cold idle. Usually fixed itself when I tapped the gas. No other funtions seem affected. No, the truck barely starts and i have to keep my foot on the gas. Once warm, it barely idles below 500 rpm. Also I notice a high-histle sound at 2500rpm like a blow off valve. The truck is well maintained and replaced plugs, wires, all filters recently. NO CHECK ENGINE LIGHT ON