Hope someone can give me some help. My 2000 Blazer with 4.3, automatic, 4 button transfer case and 150,000 miles. Out of the blue started running rough and has no power. Cap and rotor are 2 yrs old, plug wires are a year old and plugs have 50,000 miles on them. SES light is on for fuel trim but still ran alright, but when started running bad the ses light sometimes flashes but not all the time. The truck had been driven earlier in the day and was fine, stopped and shut it off for about 5 minutes, then left again and it began. At times it will barely run 15 mph or maybe a little faster with no power.

 

Have you checked the fuel pressure yet?

 

Have not checked fuel pressure yet. Went into town to check for codes, multiple misfires on different cylinders, fuel trim on both banks and if I remember right high voltage on o2 sensor. Came home and it ran fine like it always has. Left to run an errand and it started running badly again but within a mile started running fine again. Thanks for the reply Cleburne red, will check that also .

 

Lots of problems with these trucks are due to fuel system woes. Really good practice to check fuel pressure first with any type of driveablility issues. Most parts stores have a free rental pressure checker available

 

Thanks again Cleburne red, will be 1st thing I check.