2008 Blazer automatic will start fine but randomly will not accelerate. The engine will run fine at idle rpms but won't throttle up whether it's in any gear position including neutral. Keep trying to go and will finally take off but it doesn't do it every time. Any suggestions???? thanks , gregjo1948

 

Couple questions to start with as the 2008 is fairly new, nevertheless...

Has the engine been changed or been worked on?
Has anybody done some electrical work?
Has anything happened to the Blazer? (Electrical fire, engine mishap, accident?)
Are there any codes present, SES light?