2003 GMC Sierra Four Wheel Drive Automatic 126950 miles
I have a 2003 Sierra 5.3L. My problem is that once the engine is up to temperature the idle will fluctuate. It will hunt down as low as 300 RPM. It does this while it is in park or in drive while stopped at a light. It does not stall but sounds like it wants to. I noticed that when it is hunting the volt meter drops below 14 Volts. Sometimes as low as 10V. I change the fuel filter once a year and it was changed less than 6 months ago. I checked the fuel pressure and it was 45-50 PSI. The check engine light is not on and I scanned the computer and did not return any codes. Plugs and wires were changed at 100K miles. It now has about 126K miles. What do you think?
Tuesday, February 19th, 2008 AT 11:18 AM